Pathophysiology of Generalized Pustular Psoriasis

Expanding the therapeutic horizons of spesolimab: a review of off-label applications for inflammatory skin diseases

PURPOSE

This review aims to outline the crucial role of IL-36 signaling in inflammatory skin diseases and summarize the therapeutic potential of spesolimab. Our goal is to provide insights into the off-label applications of spesolimab and future directions for its use in treating other challenging skin diseases.

MATERIALS AND METHODS

We conducted a comprehensive literature search across PubMed, Embase, Web of Science, MEDLINE, Scopus, and the Cochrane Library to identify relevant studies. For RCTs, we additionally searched the ClinicalTrials.gov database.

RESULTS

In this review, we examine its off-label applications for conditions such as palmoplantar pustulosis, acrodermatitis continua of Hallopeau, hidradenitis suppurativa, pyoderma gangrenosum, and acute generalized exanthematous pustulosis. This review also explores the role of IL-36 in the pathophysiology of these disorders and discusses how spesolimab may address the limitations of current therapies for refractory cases. Randomized controlled trials and case reports are summarized to highlight the efficacy and tolerability of spesolimab across various inflammatory skin conditions. We highlight the challenges presented by the absence of standardized treatment guidelines and the need for larger clinical trials.

CONCLUSIONS

This review underscores the potential of spesolimab to enhance treatment strategies for inflammatory skin diseases.

Generalized Pustular Psoriasis with Cushing's Syndrome: A Case of Effective Spesolimab Treatment

Generalized pustular psoriasis (GPP) is a rare neutrophilic skin disease characterized by persistent symptoms and sudden onset of painful, sterile pustules. These pustules may be accompanied by systemic inflammation and can be life-threatening in severe cases. Presently, there is an absence of standardized guidelines for treatment, and the majority of conventional treatments employed by clinicians are predicated on the utilization of glucocorticosteroids, immunosuppressants, and retinoids to attain anti-inflammatory and immune-suppressing effects. However, the therapeutic effect is often unsatisfactory and patients are prone to side effects. The IL-36 receptor monoclonal antibody, Spesolimab, signifies a novel therapeutic modality that has received approval from both the National Drug Administration (NMPA) of China and the US Food and Drug Administration (FDA) for the management of acute exacerbations of GPP. We report a case of a 40-year-old male patient diagnosed with GPP who had no significant improvement in symptoms and development of Cushing's syndrome after up to six months of treatment with glucocorticoids, immunosuppressants, and retinoids. The patient was treated with Spesolimab, a monoclonal antibody, resulting in a substantial improvement in symptoms. This development offers novel treatment options and provides a reference for clinical medication for patients with this particular type of GPP.

Update on Generalized Pustular Psoriasis

Generalized pustular psoriasis (GPP) is a rare but severe inflammatory skin disease characterized by the eruption of widespread sterile pustules, often accompanied by systemic inflammation. Although GPP can coexist with plaque psoriasis, it is increasingly recognized as a distinct entity with unique clinicopathological, immunologic, and genetic features. The dysregulated IL-36 pathway, including mutations in the IL36RN gene, is implicated in GPP pathogenesis, providing a molecular basis for targeted therapies. Diagnosing GPP requires a comprehensive evaluation, including clinical presentation, potential triggers, patient history, histopathologic findings, and laboratory results. Disease severity must be assessed through both cutaneous symptoms and systemic involvement, as GPP flares can lead to life-threatening complications such as sepsis and multi-organ failure. Historically, GPP treatment primarily relied on therapies approved for plaque psoriasis, despite their limited specificity for this condition. Recent advances in understanding the molecular mechanisms of GPP, particularly the central role of interleukin-36 pathway, have led to the development of targeted therapies for this rare condition. Currently, spesolimab is the only therapy specifically approved for treating GPP flares in adolescents and adults, in both Europe and the United States of America. However, the management of GPP remains complex and challenging. This narrative review provides an overview of the epidemiology, pathophysiology, clinical features, comorbidities, and evolving therapeutic strategies for GPP.

Indian expert Delphi consensus on the diagnosis and management of flares of generalised pustular psoriasis

Generalised pustular psoriasis (GPP) is a chronic, multisystemic, autoinflammatory disease with predominantly cutaneous manifestations, characterised by recurrent episodes of widespread, macroscopic and aseptic pustules. It has a highly unpredictable, heterogeneous and unstable clinical course. There are no consensus guidelines in India for the management of GPP. The objective of this Delphi panel study was to achieve consensus on problem areas in the understanding and management of GPP. Based on the inputs from an expert panel, 19 topics across six domains were identified as being important regarding the understanding and management of GPP. Statements were developed for these 19 topics, and consensus for the statements was sought using the modified Delphi method. Twelve experts evaluated the statements, indicating their agreement or disagreement. Consensus was considered to be reached when ≥80% of experts agreed with a statement. After two rounds of discussion, consensus was reached for 17 out of 19 (89%) statements and no consensus was achieved for two (11%) statements. We have presented the statements along with the respective degrees of consensus. Wherever relevant, clarifications or additional comments by experts are provided in the document.

Interventions in cytokine signaling: novel horizons for psoriasis treatment

Intricate interactions between immune cells and cytokines define psoriasis, a chronic inflammatory skin condition that is immunological-mediated. Cytokines, including interleukins (ILs), interferons (IFNs), tumor necrosis factors (TNFs), chemokines, and transforming growth factor-β (TGF-β), are essential for controlling cellular activity and immunological responses, maintaining homeostasis and contributing to the pathogenesis of psoriasis. These molecules modulate the immune microenvironment by either promoting or suppressing inflammation, which significantly impacts therapeutic outcomes. Recent research indicates that treatment strategies targeting cytokines and chemokines have significant potential, offering new approaches for regulating the immune system, inhibiting the progression of psoriasis, and reducing adverse effects of traditional therapies. This review consolidates current knowledge on cytokine and chemokine signaling pathways in psoriasis and examines their significance in treatment. Specific attention is given to cytokines like IL-17, IL-23, and TNF-α, underscoring the necessity for innovative therapies to modulate these pathways and address inflammatory processes. This review emphasizes the principal part of cytokines in the -pathological process of psoriasis and explores the challenges and opportunities they present for therapeutic intervention. Furthermore, we examine recent advancements in targeted therapies, with a particular focus on monoclonal antibodies, in ongoing research and clinical trials.

Early Neutrophil Activation in Psoriatic Skin at Relapse Following Dead Sea Climatotherapy

Psoriasis, a chronic inflammatory skin disorder characterised by erythematous and scaly plaques, can be both physically and emotionally distressing for patients. Dead Sea climatotherapy (DSC), a treatment modality combining sun exposure, mineral-rich water and mud therapy during 4 weeks at Ein Gedi, Israel, is used for a small group of patients with psoriasis. This study aimed to investigate the cellular composition of psoriatic skin lesions at relapse after complete clearance from DSC. Skin biopsies from baseline, end of treatment and relapse were collected from eight patients with plaque psoriasis who achieved complete clearance from Dead Sea climatotherapy treatment. These biopsies were subjected to immunohistochemistry, RNA sequencing and quantitative polymerase chain reaction analysis (qPCR). Our findings demonstrate that DSC effectively reduces inflammatory markers to levels comparable to baseline non-lesional skin in the short term. The differential expression analysis identified several upregulated differentially expressed genes, including OSM, CXCL8, TREM1, CXCL1, CSF3R, BCL2A1 and CXCL2, in relapsed psoriasis skin compared with baseline lesional skin. These findings were confirmed by qPCR analysis. Pathway enrichment analysis indicated a marked upregulation of neutrophil-associated pathways in relapse skin compared with baseline lesional skin. Immunohistochemical staining for neutrophil markers, such as CD11b, CD15, CD66b, CD207, MPO and NE, showed a non-significant trend towards enhanced neutrophil infiltration and activation at relapse. In conclusion, while DSC provides short-term effectiveness in managing psoriasis, the initial relapse phase is associated with neutrophil activation and migration. Thus, targeting neutrophils early in the psoriasis disease course may disturb the evolution of psoriasis, potentially preventing disease chronicity.

Proteomic Profiling and Clinical Insights: The Role of MMP9 in Differentiating Psoriasis Vulgaris from Generalized Pustular Psoriasis

Background

Generalized pustular psoriasis (GPP) constitutes a rare, severe inflammatory disorder that differs from psoriasis vulgaris (PV). The IL-36 pathway has been identified as a key element in GPP pathogenesis.

Objective

To explore protein expression between PV and GPP, providing insights into potential mechanisms.

Methods

We performed proteomic analysis of tissue specimens from patients with PV and GPP to identify differentially expressed proteins. Comparative analysis of the proteomic data was performed and proteins with significant differences were further identified using immunofluorescence and Western blot techniques. Differential proteins were also explored by evaluating the efficacy of IL-36R inhibitors before and after GPP treatment, providing potential avenues for targeted therapeutic strategies.

Results

Tissue proteomic profiling showed that matrix metallopeptidase 9 (MMP9) increased significantly in the GPP as compared to PV. Immunofluorescence and Western blot analysis confirmed that MMP9 is higher expressed in GPP. And after therapy with IL-36 inhibitors showed that the level of MMP9 expression was markedly reduced.

Conclusion

MMP9 may be involved with the pathogenesis of GPP.

Oxidative Stress and Generalised Pustular Psoriasis: Report of d-ROM Measurements in Nine Cases Including Three of Pustular Psoriasis of Pregnancy

Reactive oxygen species (ROS) are involved in the pathogenesis of generalised pustular psoriasis (GPP), but this involvement has not been fully elucidated. We performed the diacron-reactive oxygen metabolite (d-ROM) test and the biological antioxidant potential (BAP) test on sera from nine patients with active GPP who were hospitalised and treated at our hospital, including three patients with pustular psoriasis of pregnancy (PPP). The serum d-ROM and BAP levels were evaluated before treatment and at 1 month of treatment. We also performed immunostaining of 4-hydroxy-2-nonenal (4-HNE) in skin tissues. In the GPP patients, the average d-ROM levels were significantly reduced at 1 month of treatment (reduced to 343.0 ± 82.1 U.Carr from 423.2 ± 95.0 U.Carr, p = 0.005). The Generalised Pustular Psoriasis Area and Severity Index (GPPASI) score correlated with d-ROM levels (r = 0.57, p = 0.10), suggesting that those levels reflect the disease severity. In normal pregnancy, d-ROM values are known to increase from mid-term to late-term. The d-ROM values increased when GPP worsened in the case of PPP. Immunohistochemical staining of 4-HNE was positive for subcorneal pustules, neutrophils, and for the cytoplasm of epidermal keratinocytes, especially in upper epidermal layers. Our findings indicate that 4-HNE may play an important role in GPP and PPP.

Considerations for defining and diagnosing generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare, chronic skin disease, characterized by widespread pustules and erythema, often accompanied with systemic signs and symptoms. GPP flares occur episodically but may be protracted. Left untreated, GPP can be life-threatening. Despite being first reported over 100 years ago, definitions and diagnostic criteria for GPP have been inconsistent and varied due, in part, to its rarity and a limited understanding of its pathogenesis. As such, many patients with GPP face delays in diagnosis and subsequent treatment. This manuscript aims to increase the recognition of GPP and provide foundational considerations to aid in the definition and diagnosis of this disease.

Spesolimab: A Review of the First IL-36 Blocker Approved for Generalized Pustular Psoriasis

OBJECTIVE

This article reviews clinical trial data that assesses the safety, efficacy, and clinical application of spesolimab, an interleukin-36 (IL-36) blocker, for the treatment of generalized pustular psoriasis (GPP).

DATA SOURCES

A review of the literature was conducted using the search terms: "spesolimab," "BI 655130," and "spevigo" in MEDLINE (PubMed) and Clinicaltrials.gov from January 1, 1950 to October 31, 2023.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles in English relating to the pharmacodynamics, pharmacokinetics, efficacy, and safety of spesolimab were included.

DATA SYNTHESIS

In one phase 2 clinical trial evaluating single dose IV spesolimab for GPP flares at day 8, 54% of patients receiving spesolimab had a GPP physician global assessment (GPPGA) pustulation subscore of 0, and 43% had a GPPGA total score of 0 compared with 6% and 11% for the placebo group, respectively. Another phase 2 clinical trial assessing subcutaneous spesolimab found 23% of patients in low-dose, 29% in medium-dose, and 10% of high-dose spesolimab had flares by week 48 compared with 52% of the placebo group. Hazard ratios for time to GPP flare compared with placebo were 0.16 (P = 0.0005), 0.35 (P = 0.0057), and 0.47 (P = 0.027) for the spesolimab groups, respectively. Infection rates were similar across treatment and placebo groups, and severe adverse events such as drug reactions with eosinophilia and systemic symptom (DRESS), cholelithiasis, and breast cancer occurred with spesolimab.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS

Spesolimab is a first-in-class IL-36 monoclonal antibody receptor antagonist approved for the treatment of acute GPP flares. It is a safe and effective therapeutic agent in preventing future GPP flares, with no current comparator trials with other GPP agents.

CONCLUSION

Spesolimab is a safe and effective treatment for acute GPP flares in adults. Future clinical trials can establish safety and efficacy compared with other agents.

Pustular mycosis fungoides has a poor outcome: a multicentric clinicopathological and molecular case series

BACKGROUND

Mycosis fungoides (MF) usually has an indolent course. However, some patients develop more aggressive disease and few prognostic parameters have been identified. Isolated cases of pustular MF (pMF) suggest an unfavourable prognosis.

OBJECTIVES

To describe the clinicopathological characteristics and prognostic value of pMF.

METHODS

We retrospectively collected data from all patients with MF with histological pustules diagnosed from 2009 to 2020. The outcomes and clinicopathological characteristics of pMF at diagnosis (pMFD) were compared with those of a cohort of patients with nonpustular MF (NpMF).

RESULTS

Thirty-three patients with pMF (including 22 with pMFD) and 86 with NpMF were included. Median age at diagnosis of pMF was 61 years [interquartile range (IQR) 50-75]. The median duration of follow-up for patients with pMFD was 32 months (IQR 14-49). Clinically, 33% of patients with pMF had pustules. Large cell transformation (LCT) occurred in 17 patients. Patients with pMFD had significantly more advanced-stage disease and showed more LCT at diagnosis than those with NpMF [50% vs. 7% (P < 0.001) and 23% vs. 0% (P < 0.001), respectively]. On multivariate Cox analysis, the presence of histological pustules at diagnosis was associated with shorter overall survival (OS) in all patients [hazard ratio (HR) 13.90, 95% confidence interval (CI) 2.40-79.00); P = 0.003] and in patients with early-stage disease (HR 11.09, 95% CI 1.56-78.82; P = 0.02). In multivariate Fine and Gray model analysis, pMFD was associated with a higher cumulative incidence of LCT (subdistribution HR 13.90, 95% CI 2.43-79.00; P = 0.003) in all patients. Median OS after the occurrence of histological pustules during follow-up in all patients with pMF was 37 months, with a 5-year OS rate of 25% (95% CI 0.06-0.50).

CONCLUSIONS

pMF often follows an aggressive course, with a high risk of LCT and shorter survival, even for patients with early-stage disease. Histological pustules at diagnosis of MF might represent an independent poor prognostic factor, to be confirmed by further studies. As pustules are not always identified clinically, pustules found on histology should be mentioned in MF pathology reports and should prompt discussion of closer follow-up.

Successful Treatment of Pediatric Generalized Pustular Psoriasis (GPP) with Spesolimab: 5 Case Reports and Evaluations of Circulating IL-36 Levels

Background

Generalized pustular psoriasis (GPP) is a rare, severe, and potentially life-threatening inflammatory cutaneous disease. IL-36 is a key treatment target in GPP. Spesolimab, a humanized monoclonal antibody of the IL-36 receptor, has demonstrated a good efficacy and a favorable safety profile in adults with GPP. However, data on its use in children are scarce.

Methods

We treated patients aged 4-12 years with GPP with a single dose of spesolimab. The Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) total score, GPPGA pustulation sub-score, Generalized Pustular Psoriasis Area and Severity Index (GPPASI), and the Japanese Dermatological Association severity index for GPP were evaluated. The levels of IL-36α, IL-36β, and IL-36γ were detected by the magnetic bead-based immunoassays, and the levels of IL-17A, IL-17C, IFN-γ, TNF, IL-6, and IL-8 were measured by the Olink proximity extension assay technology.

Results

We included five patients (four boys and one girl) with a median age was 6.9 years old (range: 4.8 to 10.6 years), and a median age of onset of 1.7 years (range: 3 months-10 years and 5 months). After 1 week of spesolimab administration, all patients had a total GPPGA score of 0/1 and pustulation subscore of 0, all patients had a GPPASI of 50, and four patients had a GPPASI of 75. Meanwhile, plasma levels of IL-36α, IL-36β, IL-36γ, IL-17A, IL-17C, IFN-γ, TNF, IL-6, IL-8 all decreased, and those of IL-36α, IL-36β, IL-17A, IL-17C, and IL-6 were statistically significant. There was no recurrence after 2 to 8 months of treatment. No other adverse event was recorded apart from one patient who experienced an upper respiratory infection in the first week.

Conclusion

Spesolimab might be a prospective option for children aged 4 to 12 years.

Deciphering the Etiologies of Adult Erythroderma: An Updated Guide to Presentations, Diagnostic Tools, Pathophysiologies, and Treatments

Erythroderma, an inflammatory skin condition characterized by widespread erythema with variable degrees of exfoliation, pustulation, or vesiculobullous formation, is associated with high morbidity and mortality. Determining the underlying cause of erythroderma frequently presents a diagnostic challenge, which may contribute to the condition's relatively poor prognosis. This review covers the clinical presentation, pathophysiology, diagnosis, and treatment of erythroderma. It discusses similarities and differences among the many underlying etiologies of the condition and differences between erythrodermic and non-erythrodermic presentations of the same dermatosis. Finally, this article explores current research that may provide future tools in the diagnosis and management of erythroderma.

Biologics for generalized pustular psoriasis: a systematic review and single-arm meta-analysis

Introduction

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening auto-inflammatory disease. Currently, there are no consensus-based guidelines or universally accepted treatments. Biologics represent a potential therapeutic option. This study systematically assessed the efficacy and safety of biologics in GPP.

Methods

Relevant studies from three databases were systematically searched until June 28, 2024. Statistical information, including the single-arm proportion rate of the outcomes and 95% confidence intervals (CIs), was analyzed to determine treatment effects. Heterogeneity was assessed using I² values, and subgroup analyses were performed based on drug targets and treatment durations. Data were quantitatively synthesized using a random-effects meta-analysis. Analyses were performed using R statistical software version 4.4.0.

Results

A total of 329 patients from 16 studies were included. The proportion of responders treated with IL-36 inhibitors and IL-17 inhibitors is higher than those treated with TNF-α inhibitors and IL-23 inhibitors. IL-36 inhibitors appear to achieve the highest response rates between 4 and 8 weeks, while IL-17 inhibitors, TNF-alpha inhibitors, and IL-23 inhibitors show a gradual increase in response rates up to 12 weeks. IL-36 inhibitors achieve a 40% (95% CI: 27%-54%) GPPASI75 response rate and a 55% (95% CI: 41%-68%) GPPGA (0,1) response rate within 2 weeks, significantly outperforming other biologics. The recurrence rates of GPP within 52 weeks, ranked from highest to lowest, are: IL-36 inhibitors (21% [95% CI: 9%-28%]), TNF-alpha inhibitors (20% [95% CI: 2%-46%]), IL-17 inhibitors (15% [95% CI: 1%-37%]), and IL-23 inhibitors (5% [95% CI: 0%-29%]). Additionally, 6% (95% CI: 1%-11%) of patients experienced severe adverse events.

Discussion

This meta-analysis highlights the efficacy and safety of biologics in patients with GPP, offering valuable evidence to guide future clinical practice. IL-36 inhibitors show a faster and more substantial clinical response in GPP compared to other biologics. Further research is necessary to assess their role in specific subpopulations and to evaluate their potential long-term effects on flare prevention.

Pustular Erythroderma in an Infant

An infant boy presented with generalized rash, fever, and severe skin pain. What is your diagnosis?

Non-invasive epidermal proteome assessment-based diagnosis and molecular subclassification of psoriasis and eczematous dermatitis

Background

Immunologic heterogeneity is known to exist within both eczematous dermatitis and psoriasis; however, selection of molecularly targeted therapies for individual patients generally does assess for or incorporate such information about patient-specific immune changes.

Objective

We sought to develop a rapid, non-invasive method for obtaining and analyzing epidermal protein biomarkers from skin and utilize this methodology to dissect immunologic heterogeneity in both psoriasis and eczematous dermatitis.

Methods

We optimize and evaluate detergent-based immune profiling system (DIPS) which utilizes a combination of two detergents to solubilize full-thickness epidermis when applied to the skin with an applicator. Downstream proteomic profiling of this material allows high-throughput immunologic characterization of immune biomarkers.

Results

DIPS was performed on 43 patients with psoriasis and 27 patients with eczematous dermatitis. This approach was found to be painless, nonscarring, and enabled rapid turnaround from sample collection to data output. We used this approach to accurately differentiate psoriasis and eczema using a limited set of proteins and to identify cases of eczema/psoriasis overlap with non-canonical molecular profiles. Additionally, we measured patient-specific cytokine profiles in eczema that correlated with response to IL-4Rα blockade.

Conclusion

DIPS is a promising new non-invasive cutaneous immune profiling approach that can deconvolute immune heterogeneity amongst patients with both psoriasis and eczematous dermatitis.

Clinical Implication

DIPS has potential applications in both research and day-to-day dermatologic practice and may help personalize diagnosis and medication selection in patients with inflammatory skin diseases.

Capsule summary

Detergent-based immune profiling system (DIPS), a novel non-invasive approach for molecular evaluation of skin disease, is described and evaluated in psoriasis and eczematous dermatitis.

[Translated article] Improvements in the Management of Patients With Generalized Pustular Psoriasis in Spain: Recommendations From a Group of Experts

This consensus document analyzed the management and emotional journey of patients with GPP (generalized pustular psoriasis), and the desirable course of the disease while detecting critical points and translating them into needs and recommendations. This project was conducted in 3 phases with participation from an advisory committee (n=8), an expert panel (n=15) and patients with GPP (n=6). The patients' disease progression was heterogeneous due to disease variations, different health care models implemented and available resources, and the lack of diagnostic and treatment guidelines. A total of 45 different recommendations have been made to optimize management and address the emotional component of these patients. Five of them stand out for their impact and viability. Therefore, a roadmap of priorities has been made generally available to improve the management of patients with GPP.

Current Treatments for Generalized Pustular Psoriasis: A Narrative Summary of a Systematic Literature Search

Generalized pustular psoriasis (GPP) is a rare, chronic and potentially life-threatening autoinflammatory skin disease characterized by widespread eruption of sterile pustules, with or without systemic inflammation. GPP can significantly reduce patients' quality of life (QoL). Several therapeutic approaches have been described in the literature, but there is no consensus on optimal treatment. In this review, we summarize published literature on efficacy, safety and QoL outcomes associated with current treatment of GPP with both approved and non-approved products. Embase and MEDLINE databases were searched (1980-September 2023). A search protocol was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered on the PROSPERO database (CRD42021215437). Details on publication, population, intervention, efficacy, safety and QoL were captured and checked by independent reviewers. In total, 118 publications were included, with only 19% of publications reporting on the results of clinical trials. Treatment modalities reported for GPP included non-biologic systemic therapies such as retinoids, cyclosporine and methotrexate, topical agents, biologics and small molecules, among others. Results were highly heterogeneous and methodological quality was very low, with only the interleukin-36R inhibitor spesolimab reporting results from placebo-controlled randomized trials; based on this, spesolimab is now approved for GPP treatment in regions including the USA, Japan, China, the EU and several other countries. Some other biologics are approved exclusively in Japan and Taiwan for the treatment of GPP based on open-label studies with small patient numbers in lieu of double-blind studies. Non-standardization of clinical outcomes across studies remains a major hurdle in reaching a consensus on optimal treatment. However, recently trials have been conducted using well-defined, disease-specific endpoints to evaluate GPP-targeted treatments, which will hopefully advance patient care. In conclusion, this review highlights the need for prospective randomized studies with GPP-specific endpoints to determine the optimal treatment strategy.

Improvements in the Management of Patients With Generalized Pustular Psoriasis in Spain: Recommendations From a Group of Experts

This consensus document analyzed the management and emotional journey of patients with GPP (generalized pustular psoriasis), and the desirable course of the disease while detecting critical points and translating them into needs and recommendations. This project was conducted in 3 phases with participation from an advisory committee (n=8), an expert panel (n=15) and patients with GPP (n=6). The patients' disease progression was heterogeneous due to disease variations, different health care models implemented and available resources, and the lack of diagnostic and treatment guidelines. A total of 45 different recommendations have been made to optimize management and address the emotional component of these patients. Five of them stand out for their impact and viability. Therefore, a roadmap of priorities has been made generally available to improve the management of patients with GPP.

RNA-binding proteins potentially regulate alternative splicing of immune/inflammatory-associated genes during the progression of generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare but severe form of psoriasis. However, the pathogenesis of GPP has not been fully elucidated. Although RNA-binding proteins (RBPs) and the alternative splicing (AS) process are essential for regulating post-transcriptional gene expression, their roles in GPP are still unclear. We aimed to elucidate the regulatory mechanisms to identify potential new therapeutic targets. Here, We analyzed an RNA sequencing (RNA-seq) dataset (GSE200977) of peripheral blood mononuclear cells (PBMCs) of 24 patients with GPP, psoriasis vulgaris (PV), and healthy controls (HCs) from the Gene Expression Omnibus (GEO) database. We found that the abnormal alternative splicing (AS) events associated with GPP were mainly "alt3p/alt5p", and 15 AS genes were differentially expressed. Notably, the proportions of different immune cell types were correlated with the expression levels of regulatory alternatively spliced genes (RASGs): significant differences were observed in expression levels of DTD2, NDUFAF3, NBPF15, and FBLN7 in B cells and ARFIP1, IPO11, and RP11-326L24.9 in neutrophils in the GPP samples. Furthermore, We identified 32 differentially expressed RNA-binding proteins (RBPs) (18 up-regulated and 14 down-regulated). Co-expression networks between 14 pairs of differentially expressed RBPs and RASGs were subsequently constructed, demonstrating that these differentially expressed RBPs may affect the progression of GPP by regulating the AS of downstream immune/inflammatory-related genes such as LINC00989, ENC1 and MMP25-AS1. Our results were innovative in revealing the involvement of inflammation-related RBPs and RASGs in the development of GPP from the perspective of RBP-regulated AS.

Characteristics and management of generalized pustular psoriasis (GPP): Experience from the Central and Eastern Europe (CEE) GPP Expert Network

BACKGROUND

Generalized pustular psoriasis (GPP) is a rare, inflammatory skin disease characterized by widespread eruption of sterile pustules with or without systemic symptoms.

OBJECTIVES

This study aimed to describe the demographics of patients with GPP in Central and Eastern Europe (CEE), present the clinical characteristics of individual GPP flares and explore the current treatment landscape.

METHODS

Patient demographics were collected at the times of last observation and previous treatment. Characteristics of a patient's last (most recent) and most severe (from all documented episodes) flare were provided at clinician's discretion.

RESULTS

Fifty-eight patients were recruited from 12 centres in nine CEE countries; median (range) age was 61 (16-92) years and 60.3% (35 out of 58) were female. The most common comorbidities were hypertension (43.1% [25 out of 58]) and hyperlipidaemia (32.8% [19 out of 58]). Thirty-four patients (58.6%) presented with concomitant plaque psoriasis before or during the course of GPP. Data from two separate flares were recorded in 26 individuals; in 32 patients, the most recent flare was reported as the most severe. Over 90% of patients with a flare episode classified as most severe by clinicians were hospitalized, with >75% of these individuals having a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) total score of 3 or 4. Systemic symptoms were more common in patients with a GPPGA score of 3 or 4 but were also manifest in individuals with a GPPGA score ≤2. A significant correlation was observed between a combined systemic disease score of clinical and laboratory features and both GPPGA total score (r = 0.385, p < 0.001) and GPPGA pustulation subscore (r = 0.305, p < 0.05).

CONCLUSIONS

Considerable heterogeneity in the presentation of GPP flares was observed, both between patients and within-patient. All GPP flares were associated with a significant clinical burden, highlighting the unmet need for accurate and early diagnosis.

Repeated stress to the skin amplifies neutrophil infiltration in a keratin 17- and PKCα-dependent manner

Neutrophils are the first immune cells to reach inflamed sites and contribute to the pathogenesis of chronic inflammatory skin diseases. Yet, little is known about the pattern of neutrophil infiltration in inflamed skin in vivo and the mechanisms mediating their recruitment. Here, we provide insight into the dynamics of neutrophil infiltration in skin in response to acute or repeated inflammatory stress, highlighting a novel keratinocyte- and keratin 17 (K17)-dependent mechanism that regulates neutrophil recruitment to inflamed skin. We used the phorbol ester TPA and UVB, alone or in combination, to induce sterile inflammation in mouse skin. A single TPA treatment results in a neutrophil influx in the dermis that peaks at 12 h and resolves within 24 h. A subsequent TPA treatment or a UVB challenge, when applied 24 h but not 48 h later, accelerates, amplifies, and prolongs neutrophil infiltration. This transient amplification response (TAR) is mediated by local signals in inflamed skin, can be recapitulated in ex vivo culture, and involves the K17-dependent sustainment of protein kinase Cα (PKCα) activity and release of chemoattractants by stressed keratinocytes. K17 binds RACK1, a scaffold protein essential for PKCα activity. The N-terminal head domain of K17 is crucial for its association with RACK1 and regulation of PKCα activity. Analysis of RNAseq data reveals a signature consistent with TAR and PKCα activation in inflammatory skin diseases. These findings uncover a novel, keratin-dependent mechanism that amplifies neutrophil recruitment in skin under stress, with direct implications for inflammatory skin disorders.

Biochanin A Ameliorates Imiquimod-Induced Psoriasis-Like Skin Inflammation in Mice by Modulating the NF-κB and MAPK Signaling Pathways

Psoriasis is a chronic skin inflammatory disorder characterized by the hyper-activation of the immune system and the over-proliferation of epidermal keratinocytes. This study aimed to investigate the anti-psoriatic activity of Biochanin A (BCA), a phytomolecule with known anti-inflammatory and anti-cancer properties, using the IMQ-induced psoriasis-like mouse model. Network pharmacology analysis was performed to investigate the targetability of Biochanin A (BCA) against psoriasis. Psoriasis-like skin inflammation was established using BALB/c mice by topical application of IMQ (5%). BCA cream (0.3%, 1%, 3%) was applied on the skin regions every day for 6 days. The skin phenotypes-erythema and scaling were scored every day. On the 7th day, skin tissues were collected for gene expression analysis, histopathological analysis, cytokine levels determination, and western blot analysis for signaling mechanisms. The network pharmacology analysis has identified 57 common targets between psoriasis and BCA. The topical application of IMQ induced a typical psoriasis-like skin phenotype including redness, skin thickening, and plaque formation. Upon BCA treatment, the psoriasis-like symptoms were significantly reduced in a dose-dependent manner. The targets identified by the network pharmacology (MMP9, EGFR, and PTGS2) and the pro-inflammatory cytokine gene expression were found to be significantly elevated in IMQ controls, and upon BCA treatment they were found significantly reduced. The release of cytokines linked to psoriasis (IL-17A and IL-23) were significantly reduced upon BCA treatment. Furthermore, our findings demonstrated that BCA treatment alleviated the psoriasis-like symptoms via modulating NF-κB and MAPK signaling pathways. Our results demonstrate the therapeutic potential of BCA against IMQ-induced psoriasis-like skin inflammation.

New and Emerging Treatments for Generalized Pustular Psoriasis: Focus on IL-36 Receptor Inhibitors

Generalized Pustular Psoriasis (GPP) is a rare and severe subtype of psoriasis that significantly impacts patients' quality of life. Until recently, no specific treatment modalities were available, and treatment for GPP followed the guidelines for the treatment of plaque psoriasis, consisting of conventional treatments, such as retinoids, methotrexate, and even biologics, which although effective in some cases, may be associated with significant side effects, necessitating more effective and safe options. The pathophysiology of Generalized Pustular Psoriasis is complex and not fully understood, but there is some overlap with the pathogenesis of Plaque Psoriasis. In GPP, the innate immune system seems to play a more significant role, with the interleukin (IL)-36 pathway being fundamentally involved. Spesolimab and imsidolimab, two recently developed therapeutic agents, target the IL-36 inflammatory pathway by binding to the IL-36 receptor (IL-36R). Both biologics have already been evaluated in phase 1 and 2 clinical trials and have shown promising results in terms of safety and efficacy. IL-36 receptor inhibitors demonstrated great efficacy and good safety profile in the management of patients with GPP, demonstrating their potential to emerge as a leading treatment option. This review aims to explore and summarize the current scientific literature on the most recently developed treatments for GPP.

Rare Filaggrin Variants Are Associated with Pustular Skin Diseases in Asians

Reactive pustular eruptions (RPEs) can manifest in a variety of conditions, including pustular psoriasis (PP) and adult-onset immunodeficiency syndrome due to anti-interferon-γ autoantibody (AOID). These RPEs can be attributed to different causes, one of which is genetic factors. However, the genetic basis for pustular skin diseases remains poorly understood. In our study, we conducted whole-exome sequencing on a cohort of 17 AOID patients with pustular reactions (AOID-PR) and 24 PP patients. We found that 76% and 58% of the AOID-PR and PP patients, respectively, carried rare genetic variations within the filaggrin (FLG) gene family. A total of 12 out of 21 SNPs on FLG had previously received clinical classifications, with only p.Ser2706Ter classified as pathogenic. In contrast, none of the FLG3 SNPs identified in this study had prior clinical classifications. Overall, these variations had not been previously documented in cases of pustular disorders, and two of them were entirely novel discoveries. Immunohistochemical analysis of skin biopsies revealed that FLG variants like p.Ser860Trp, p.Gly3903Ter, p.Gly2440Glu, and p.Glu2133Asp caused reductions in FLG levels similar to the pathogenic FLG p.Ser2706Ter. These results highlight rare FLG variants as potential novel genetic risk factors contributing to pustule formation in both AOID and PP.

Generalized Pustular Psoriasis and Systemic Organ Dysfunctions

This review explores the intricate relationship between generalized pustular psoriasis (GPP) and various systemic diseases, shedding light on the broader impacts of this severe skin condition beyond its primary dermatological manifestations. GPP is identified as not only a profound contributor to skin pathology but also a significant risk factor for systemic diseases affecting cardiovascular, hepatic, renal, pulmonary, and skeletal systems, as well as associated with an increased incidence of anemia, depression, anxiety, and arthritis. The research highlights the complex interplay of cytokines, particularly IL-17 and IL-36, which are central to the pathophysiology of GPP and implicated in the exacerbation of systemic conditions. Key findings indicate a higher incidence of cardiovascular events in GPP patients compared to those with other severe forms of psoriasis, notably with a stronger correlation between myocardial infarction history and GPP development. Liver disturbances, frequently reversible upon psoriasis remission, suggest a cytokine-mediated link to hepatic health. Renal dysfunction appears elevated in GPP sufferers, with IL-17 and IL-36 potentially driving renal fibrosis. Similarly, interstitial lung disease and osteoporosis in GPP patients underscore the systemic reach of inflammatory processes initiated in the skin. The associations with anemia, depression, anxiety, and arthritis further complicate the clinical management of GPP, requiring a multidisciplinary approach. The study concludes that managing GPP effectively requires a holistic approach that addresses both the cutaneous and systemic dimensions of the disease, advocating for continued research into the mechanisms that connect GPP with broader health implications to refine therapeutic strategies.

Antiproliferative and Anti-Inflammatory Effects of the Polyphenols Phloretin and Balsacone C in a Coculture of T Cells and Psoriatic Keratinocytes

Plaque psoriasis is a chronic inflammatory skin disease causing red inflamed lesions covered by scales. Leukocytes, including dendritic cells and T cells, participate in the inflammation of the skin by producing multiple cytokines, thus contributing to the hyperproliferation of keratinocytes. Lack of effectiveness and toxic side effects are the main concerns with conventional treatments, and research involving new antipsoriatic molecules is essential. In this study, the anti-inflammatory and antiproliferative effects of two natural polyphenols, phloretin and balsacone C, were investigated using the coculture of T cells and psoriatic keratinocytes. Phloretin exerted antiproliferative activity by regulating the expression of antigen Ki67 and proliferating cell nuclear antigen (PCNA). These effects were comparable to those of methotrexate, a reference treatment for moderate to severe psoriasis. With balsacone C, the expression of Ki67 was also reduced. Additionally, phloretin decreased the levels of multiple pro-inflammatory cytokines: monocyte chemoattractant protein-1 (MCP-1/CCL2), macrophage inflammatory protein-1α (MIP-1α), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 alpha (IL-1α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-17A (IL-17A), and tumor necrosis factor alpha (TNF-α). The increased interleukin-2 (IL-2) levels with phloretin and methotrexate also represented anti-inflammatory activity. Balsacone C and methotrexate decreased the levels of IL-1α and IL-1β, but methotrexate exerted a higher reduction. In summary, the anti-inflammatory effects of phloretin were more pronounced than those of methotrexate and balsacone C. In addition, the expression of lymphocyte common antigen (CD45) was more similar to that of the healthy condition after using phloretin or methotrexate. Finally, phloretin stood out from the other compounds and appears promising for psoriasis treatment.

Neutrophil IL-26 fuels autoinflammation

Pustular psoriasis is an inflammatory skin disease with features of neutrophil-mediated sterile autoinflammation. In this issue of JEM, Baldo et al. (https://doi.org/10.1084/jem.20231464) show that this autoinflammation is driven by a vicious cycle through neutrophil-derived IL-26.

The anti-inflammatory activity of flavonoids and alkaloids from Sophora flavescens alleviates psoriasiform lesions: Prenylation and methoxylation beneficially enhance bioactivity and skin targeting

The herb Sophora flavescens displays anti-inflammatory activity and can provide a source of antipsoriatic medications. We aimed to evaluate whether S. flavescens extracts and compounds can relieve psoriasiform inflammation. The ability of flavonoids (maackiain, sophoraflavanone G, leachianone A) and alkaloids (matrine, oxymatrine) isolated from S. flavescens to inhibit production of cytokine/chemokines was examined in keratinocytes and macrophages. Physicochemical properties and skin absorption were determined by in silico molecular modeling and the in vitro permeation test (IVPT) to establish the structure-permeation relationship (SPR). The ethyl acetate extract exhibited higher inhibition of interleukin (IL)-6, IL-8, and CXCL1 production in tumor necrosis factor-α-stimulated keratinocytes compared to the ethanol and water extracts. The flavonoids demonstrated higher cytokine/chemokine inhibition than alkaloids, with the prenylated flavanones (sophoraflavanone G, leachianone A) led to the highest suppression. Flavonoids exerted anti-inflammatory effects via the extracellular signal-regulated kinase, p38, activator protein-1, and nuclear factor-κB signaling pathways. In the IVPT, prenylation of the flavanone skeleton significantly promoted skin absorption from 0.01 to 0.22 nmol/mg (sophoraflavanone G vs. eriodictyol). Further methoxylation of a prenylated flavanone (leachianone A) elevated skin absorption to 2.65 nmol/mg. Topical leachianone A reduced the epidermal thickness in IMQ-treated mice by 47%, and inhibited cutaneous scaling and cytokine/chemokine overexpression at comparable levels to a commercial betamethasone product. Thus, prenylation and methoxylation of S. flavescens flavanones may enable the design of novel antipsoriatic agents.

Generalized pustular psoriasis in a toddler with IL36RN mutation: a case report

Generalized Pustular Psoriasis (GPP) is a dermatological autoinflammatory disease that rarely occurs in children and is associated with complex genetic factors. GPP pathogenesis has been associated with mutations in IL36RN gene, which encodes an interleukin-36 receptor antagonist. GPP usually occurs without a history of psoriasis in the patients or their family members. This case report describes the clinical course of a 3-year-old toddler with GPP. The diagnosis of GPP was confirmed through a comprehensive series of examinations, and genetic testing revealed an IL36RN mutation, providing further insight into the genetic basis of the condition. This case highlights the importance of a genetic perspective for diagnosing GPP, particularly in children.

Exploring the Clinical Presentation, Course, and Burden of Disease in Generalized Pustular Psoriasis [Podcast]

Generalized pustular psoriasis (GPP) is the most severe form of pustular psoriasis and affects large areas of the body. GPP is a rare disease, and has a variable presentation; thus, its diagnosis is challenging. The onset of symptoms is rapid, with the appearance of painful skin erythema, followed by the widespread eruption of sterile pustules. Acute GPP (called a flare) is often accompanied by systemic symptoms, including high fever, pain in skin lesions, malaise, and fatigue. Approximately half of GPP flares require hospitalization, with an average inpatient duration of 10-14 days. GPP prevalence estimates range from approximately 2-124 cases per million persons, with a female predominance. The most common age of onset of GPP is 40-60 years, although cases have been described in younger adults and children. GPP affects every aspect of patients' lives and has a high physical and psycho-social impact. Recent research on the interleukin-36 pathway associated with GPP led to the development of a GPP-specific treatment, spesolimab, which was approved by the US FDA in September 2022. This podcast explores the clinical presentation, disease course, and burden of disease in GPP, including differential diagnosis and common triggers of an acute flare.

Generalized pustular psoriasis successfully treated with spesolimab: A case report

Generalized pustular psoriasis is defined as a primary, sterile, macroscopically visible pustular eruption on non-acral skin, which can occur with or without systemic inflammation and/or psoriasis vulgaris, and can either be relapsing or be persistent, according to the European Rare and Severe Psoriasis Expert Network. The treatment of generalized pustular psoriasis may be challenging. We describe a 48-year-old woman with a 15-year history of severe generalized pustular psoriasis and plaque psoriasis resistant to multiple courses of treatments with conventional and biological agents who had a rapid, complete and durable (up to 12 months) clinical remission with spesolimab, an anti-interleukin-36 receptor antagonist monoclonal antibody recently approved for the treatment of generalized pustular psoriasis flares.

Successful treatment of acrodermatitis continua of Hallopeau coexisting with generalized pustular psoriasis with spesolimab: a case report

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory pustular dermatosis that presents as painful erythema with sterile pustules on nonacral skin. No unified standard and guideline for the treatment of GPP has been established. Several biologics have been tried for GPP, with varying success. Acrodermatitis continua of Hallopeau (ACH) is a very rare disabling variant of pustular psoriasis characterized by sterile pustules on the fingers and toes, including the nail bed. Comparatively, treating ACH is highly challenging due to its commonly therapy-resistant disease course. The pathogenic role of IL-36 signaling axis has been currently identified in GPP development. Spesolimab, the first anti-interleukin-36 receptor biologic, has been approved for treating GPP flares and shown promising results. In view of a shared pathogenesis between GPP and ACH, specolimab may be an effective treatment for ACH. Currently, there is no case and clinical trial data exist on this condition. Therefore, this case was aim to describe real-world experience of spesolimab use in ACH coexisting with GPP. We report an Asian patient with a 16-year-history of GPP and ACH with marked pustulosis on the nail bed and onychodystrophy. He received conventional systemic regimen acitretin, cyclosporine and biologics adalimumab and secukinumab, but experienced relapse for skin lesions and refractory for nail lesions. He was then treated with a single dose of spesolimab in combination with secukinumab, which resulted in skin clearance and nearly complete resolution of nail lesions over a 32-week period. Our observation suggests that spesolimab should be considered for the treatment of ACH, especially in the patients with intractable nail lesions and concomitant GPP.

Clinical and Disease Burden of Patients with Generalized Pustular Psoriasis: A Review of Real-World Evidence

Generalized pustular psoriasis (GPP) is a chronic, rare, and potentially life-threatening disease. There is limited understanding of patient characteristics in GPP and their correlation with disease progression or healthcare resource utilization. Our review aims to examine real-world evidence on these characteristics and the associated disease burden as related to economic and quality of life factors. Results showed that most patients with GPP experienced flares once a year, lasting from 2 weeks to 3 months, with > 80% of patients having residual disease post-flare, with/without treatment, indicating the long-term nature of GPP. The impact of GPP on patients' daily activities was significant, even in the absence of a flare. GPP adversely affected mental health, and anxiety and depression were reported regularly. Patients with GPP had more comorbidities, were prescribed more medication, and had more inpatient and outpatient visits than in matched plaque psoriasis or general population cohorts. Improving the education of healthcare providers in diagnosing GPP, defining disease flares, and managing the disease, as well as making globally accepted clinical guidelines for GPP treatment available, could help to reduce the burden on patients with GPP. Effective therapies that control and prevent GPP flares and manage chronic disease are needed.

Low grade of satisfaction related to the use of current systemic therapies among pustular psoriasis patients: a therapeutic unmet need to be fulfilled

Introduction

Pustular psoriasis is considered a separate entity from plaque psoriasis and can be categorized as generalized pustular psoriasis (GPP), acrodermatitis continua of Hallopeau, or palmoplantar pustulosis (PPP). Current guidelines mostly include treatment options that have not been specifically developed for the treatment of pustular psoriasis. The majority of them does not have indication for the treatment of pustular psoriasis. Their effectiveness and safeness have been described in small cohort-based studies or case series with a low level of evidence. Previous studies evaluated treatment response through physician-based assessment but none reported patient satisfaction to treatment, quality of life and patient perception of disease severity during systemic therapies, particularly with biologics commonly used in plaque psoriasis. This study aimed to investigate patient satisfaction to treatment and patients' quality of life during treatment, correlating patient-reported outcomes with residual disease severity.

Methods

A cross-sectional, cohort-based, single center study included patients affected by pustular psoriasis undergoing treatment with systemic agents. Demographic, clinical characteristics were collected. Treatment satisfaction as well as disease severity were assessed through dedicated assessment scores.

Results

A total of 31 patients affected by GPP or PPP were included. Despite biologic treatment, 80.6% of patients continued to experience mild-to-severe disease activity, with discrepancies between patient and physician assessments. Patients reported a substantial impairment in their quality of life, with notable limitations in physical activity and emotional distress. Mental health conditions, such as depression and anxiety disorders, were common. Treatment satisfaction varied, with moderate scores for effectiveness and convenience. Only a small proportion of patients (41.9%) reported complete or high overall treatment satisfaction. GPP and PPP subcohorts exhibited similar quality of life and treatment satisfaction levels.

Discussion

This study highlights the suboptimal control of PP despite biologic therapies, resulting in a significant impact on patients' quality of life and treatment satisfaction. The findings highlight the need for specific therapies and standardized guidelines for managing PP. New targeted therapies, such as spesolimab, hold promise for optimizing treatment satisfaction and improving patients' quality of life in this challenging condition. Future research should focus on refining treatment strategies to address the unmet needs of PP patients comprehensively.

Neutrophil extracellular traps and neutrophilic dermatosis: an update review

Neutrophils have both antimicrobial ability and pathogenic effect in the immune system, neutrophil extracellular traps (NETs) formation is one of the representative behaviors of their dual role. NETs formation was triggered by pathogen-related components and pathogen non-related proteins as cytokines to exert its effector functions. Recent studies indicate that the pathogenicity of NETs contributed to several skin diseases such as psoriasis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and neutrophilic dermatosis. Especially in neutrophilic dermatosis, a heterogeneous group of inflammatory skin disorders characterized with sterile neutrophilic infiltrate on dermis, NETs formation was reported as the way of participation of neutrophils in the pathogenesis of these diseases. In this review, we describe the different processes of NETs formation, then summarized the most recent updates about the pathogenesis of neutrophilic dermatosis and the participation of NETs, including pyoderma gangrenosum and PAPA syndrome, Behçet syndrome, hidradenitis suppurativa, Sweet Syndrome, pustular dermatosis and other neutrophilic dermatosis. Furthermore, we discuss the link between NETs formation and the development of neutrophilic dermatosis.

Immune cells in the epithelial immune microenvironment of psoriasis: emerging therapeutic targets

Psoriasis is a chronic autoimmune inflammatory disease characterized by erroneous metabolism of keratinocytes. The development of psoriasis is closely related to abnormal activation and disorders of the immune system. Dysregulated skin protective mechanisms can activate inflammatory pathways within the epithelial immune microenvironment (EIME), leading to the development of autoimmune-related and inflammatory skin diseases. In this review, we initially emphasized the pathogenesis of psoriasis, paying particular attention to the interactions between the abnormal activation of immune cells and the production of cytokines in psoriasis. Subsequently, we delved into the significance of the interactions between EIME and immune cells in the emergence of psoriasis. A thorough understanding of these immune processes is crucial to the development of targeted therapies for psoriasis. Finally, we discussed the potential novel targeted therapies aimed at modulating the EIME in psoriasis. This comprehensive examination sheds light on the intricate underlying immune mechanisms and provides insights into potential therapeutic avenues of immune-mediated inflammatory diseases.

Spesolimab for the Treatment of Generalized Pustular Psoriasis

Generalized pustular psoriasis (GPP) is a rare but severe skin inflammatory disorder characterized by the eruption of widespread sterile neutrophilic pustules, often accompanied by systemic inflammation. Given its life-threatening potential, GPP requires prompt accurate diagnosis and effective treatment, but its rarity and relapsing-remitting nature pose challenges in performing large-scale randomized controlled clinical trials. Established international guidelines are currently lacking and management guidance often follows that for plaque psoriasis. However, while it can co-exist with plaque psoriasis and has traditionally been classified as a most severe form of psoriasis, GPP is now recognized as a distinct entity, with its own clinicopathological, autoinflammatory, immunologic and genetic features. Research conducted over the past decade revealed that an imbalance of interleukin (IL)-36 signaling favoring the proinflammatory activity is the central driver of the pathogenesis of GPP, thereby laying the groundwork for the development of targeted therapies for the disease. This article reviews the evidence thus far on spesolimab, a selective humanized antibody against the IL-36 receptor that was recently licensed in Europe and the United States for the treatment of GPP flares in adults. In phase II, randomized controlled clinical trials, spesolimab led to rapid and effective skin clearance in patients experiencing a GPP flare and demonstrated superiority to placebo in preventing flares for up to 48 weeks with maintenance treatment, with reassuring safety and tolerability profiles. Spesolimab is considered to be a first-in-class medication establishing itself as the standard of care for the treatment of GPP flares, thus changing the paradigm of the management of GPP to a new era of scientifically- and evidence-based targeted therapy for this distinctive disease.

Clinical characteristics and heterogeneity of generalized pustular psoriasis: A comparative study in a large retrospective cohort

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening skin disease and the clinical heterogeneity of which is largely unknown. Retrospective cohort analysis was conducted on hospitalized GPP patients between January 2010 and November 2022. A total of 416 patients with GPP and psoriasis vulgaris (PV) respectively were included, matched 1:1 by sex and age. The heterogeneity of GPP was stratified by PV history and age. Compared with PV, GPP was significantly associated with prolonged hospitalization (11.7 vs. 10.3 day, p < 0.001), elevated neutrophil lymphocyte ratio (NLR) (5.93 vs. 2.44, p < 0.001) and anemia (13.9% vs. 1.2%, p < 0.001). Moreover, GPP alone (without PV history) was a relatively severer subtype with higher temperature (37.6°C vs. 38.0°C, p = 0.002) and skin infections (5.2% vs. 11.4%, p = 0.019) than GPP with PV. For patients across different age, compared with juvenile patients, clinical features support a severer phenotype in middle-aged, including higher incidence of anaemia (7.5% vs. 16.0%, p = 0.023) and NLR score (3.83 vs. 6.88, p < 0.001). Interleukin-6 (r = 0.59), high density lipoprotein cholesterol (r = -0.56), albumin (r = -0.53) and C-reactive protein-to-albumin ratio (r = 0.49) were the most relevant markers of severity in GPP alone, GPP with PV, juvenile and middle-aged GPP, respectively. This retrospective cohort suggests that GPP is highly heterogeneous and GPP alone and middle-aged GPP exhibit severe disease phenotypes. More attention on the heterogeneity of this severe disease is warranted to meet the unmet needs and promote the individualized management of GPP.

Knowledge Mapping and Research Hotspots of Generalized Pustular Psoriasis: A Bibliometric Analysis from 2003 to 2023

Background

Generalised pustular psoriasis (GPP) is a chronic inflammatory skin disease. We aimed to visualize the research hotspots and trends of GPP using bibliometric analysis to enhance our comprehension of the future advancements in both basic science and clinical research.

Methods

Relevant publications from July 2003 to July 2023 were obtained from the Web of Science Core Collection on July 12, 2023. The analysis of countries, institutions, authors, references, and keywords associated with this subject was conducted through the utilisation of CiteSpace 6.2.R4, VOSviewer 1.6.18, and Microsoft Excel 2019.

Results

A total of 578 papers were analyzed, authored by 2758 researchers from 191 countries/regions and 1868 institutions, published in 174 academic journals. There was an overall upward trajectory in the volume of annual publications, accompanied by a gradual intensification of research interest in GPP. The United States, UDICE-French Research Universities, and Akiyama M of Nagoya University were the most productive and influential country, institution, and author, respectively. The Journal of Dermatology ranked first with the highest publications, and the Journal of the American Academy of Dermatology received the most citations. High-frequency keywords included "generalized pustular psoriasis", "psoriasis, interleukin-36", "plaque psoriasis", "skin-disease", and "antagonist deficiency". Recent research focuses have included "safety", "secukinumab", "spesolimab", "ap1s3 mutations", and "interleukin-36". Burst detection analysis of keywords showed that "moderate", "ixekizumab treatment", "mutations", "efficacy", and "safety" are current research frontiers in this field.

Conclusion

This bibliometric analysis delineated the landmark publications in GPP that have defined current research hotspots and development trends, notably the applications, efficacy, and safety of biological agents. Future research endeavors are warranted to explore other biological therapeutic options for both acute GPP and the long-term management of chronic GPP.

Autoinflammatory Keratinization Diseases-The Concept, Pathophysiology, and Clinical Implications

Recent advances in medical genetics elucidated the background of diseases characterized by superficial dermal and epidermal inflammation with resultant aberrant keratosis. This led to introducing the term autoinflammatory keratinization diseases encompassing entities in which monogenic mutations cause spontaneous activation of the innate immunity and subsequent disruption of the keratinization process. Originally, autoinflammatory keratinization diseases were attributed to pathogenic variants of CARD14 (generalized pustular psoriasis with concomitant psoriasis vulgaris, palmoplantar pustulosis, type V pityriasis rubra pilaris), IL36RN (generalized pustular psoriasis without concomitant psoriasis vulgaris, impetigo herpetiformis, acrodermatitis continua of Hallopeau), NLRP1 (familial forms of keratosis lichenoides chronica), and genes of the mevalonate pathway, i.e., MVK, PMVK, MVD, and FDPS (porokeratosis). Since then, endotypes underlying novel entities matching the concept of autoinflammatory keratinization diseases have been discovered (mutations of JAK1, POMP, and EGFR). This review describes the concept and pathophysiology of autoinflammatory keratinization diseases and outlines the characteristic clinical features of the associated entities. Furthermore, a novel term for NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) describing the spectrum of autoinflammatory keratinization diseases secondary to NLRP1 mutations is proposed.

Concurrent Presentation of Pustular Psoriasis and Late-Onset Rheumatoid Arthritis: A Diagnostic Challenge in a Community Hospital Setting

The coexistence of autoimmune diseases presents a significant diagnostic challenge in clinical practice, particularly in settings with limited resources. This case report details a rare instance of pustular psoriasis occurring concurrently with rheumatoid arthritis, underscoring the complexities involved in diagnosing overlapping autoimmune disorders. A 70-year-old male with a history of chronic heart failure, atrial fibrillation, and other comorbidities presented to a rural community hospital with a year-long persistent rash and joint and back pain. Physical examination and blood tests revealed high inflammatory markers. A dermatological assessment, including a skin biopsy, diagnosed generalized pustular psoriasis. However, the atypical presentation of acute polyarthritis led to further investigations, revealing elevated rheumatoid factor and anti-citrullinated protein antibody levels, resulting in a diagnosis of late-onset rheumatoid arthritis. The patient underwent a comprehensive treatment regime, including prednisolone, cefazolin, oral terbinafine, methotrexate, and infliximab, leading to gradual symptom improvement to the previous activity of daily life and discharge on the 27th day of hospitalization. This case illustrates the diagnostic intricacies in identifying concurrent autoimmune disorders and highlights the crucial role of general physicians in systematically approaching complex cases in resource-limited settings. It emphasizes the need for heightened clinical vigilance and a multifaceted diagnostic approach when managing patients with overlapping rheumatic symptoms, advocating for consideration of coexisting conditions in autoimmune diseases.

Generalized pustular psoriasis: practical recommendations for Spanish primary care and emergency physicians

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory skin disease that can lead to life-threatening complications and require emergency medical treatment. Recurrent GPP flares are characterized by the sudden onset of widespread erythematous skin rash with sterile pustules, at times associated with fever, chills, general malaise, and other systemic inflammatory manifestations. Systemic complications such as cardiorespiratory failure, infections, and sepsis are potentially life-threatening and can result in an emergency department visit and/or hospitalization. Acute GPP episodes can be difficult to recognize and diagnose. The low incidence of the disease, its relapsing nature, the unpredictability of flare onset, and the lack of standardized diagnostic criteria are major obstacles to achieving rapid recognition and diagnosis in both the emergency department and the hospital setting.There is scarce evidence supporting the efficacy and safety of treatments commonly used for GPP; consequently, there is an unmet need for therapies that specifically target the condition. Our aim is to present a multidisciplinary approach to GPP to achieve a rapid diagnosis ensuring that the patient receives the most appropriate treatment for their pathology. The main recommendation for primary care and emergency physicians is to contact a dermatologist immediately for advice or to refer the patient when GPP or a flare is suspected.

Efficacy and safety of subcutaneous spesolimab for the prevention of generalised pustular psoriasis flares (Effisayil 2): an international, multicentre, randomised, placebo-controlled trial

BACKGROUND

Spesolimab is an anti-interleukin-36 receptor monoclonal antibody approved to treat generalised pustular psoriasis (GPP) flares. We aimed to assess the efficacy and safety of spesolimab for GPP flare prevention.

METHODS

This multicentre, randomised, placebo-controlled, phase 2b trial was done at 60 hospitals and clinics in 20 countries. Eligible study participants were aged between 12 and 75 years with a documented history of GPP as per the European Rare and Severe Psoriasis Expert Network criteria, with a history of at least two past GPP flares, and a GPP Physician Global Assessment (GPPGA) score of 0 or 1 at screening and random assignment. Patients were randomly assigned (1:1:1:1) to receive subcutaneous placebo, subcutaneous low-dose spesolimab (300 mg loading dose followed by 150 mg every 12 weeks), subcutaneous medium-dose spesolimab (600 mg loading dose followed by 300 mg every 12 weeks), or subcutaneous high-dose spesolimab (600 mg loading dose followed by 300 mg every 4 weeks) over 48 weeks. The primary objective was to demonstrate a non-flat dose-response curve on the primary endpoint, time to first GPP flare.

FINDINGS

From June 8, 2020, to Nov 23, 2022, 157 patients were screened, of whom 123 were randomly assigned. 92 were assigned to receive spesolimab (30 high dose, 31 medium dose, and 31 low dose) and 31 to placebo. All patients were either Asian (79 [64%] of 123) or White (44 [36%]). Patient groups were similar in sex distribution (76 [62%] female and 47 [38%] male), age (mean 40·4 years, SD 15·8), and GPP Physician Global Assessment score. A non-flat dose-response relationship was established on the primary endpoint. By week 48, 35 patients had GPP flares; seven (23%) of 31 patients in the low-dose spesolimab group, nine (29%) of 31 patients in the medium-dose spesolimab group, three (10%) of 30 patients in the high-dose spesolimab group, and 16 (52%) of 31 patients in the placebo group. High-dose spesolimab was significantly superior versus placebo on the primary outcome of time to GPP flare (hazard ratio [HR]=0·16, 95% CI 0·05-0·54; p=0·0005) endpoint. HRs were 0·35 (95% CI 0·14-0·86, nominal p=0·0057) in the low-dose spesolimab group and 0·47 (0·21-1·06, p=0·027) in the medium-dose spesolimab group. We established a non-flat dose-response relationship for spesolimab compared with placebo, with statistically significant p values for each predefined model (linear p=0·0022, emax1 p=0·0024, emax2 p=0·0023, and exponential p=0·0034). Infection rates were similar across treatment arms; there were no deaths and no hypersensitivity reactions leading to discontinuation.

INTERPRETATION

High-dose spesolimab was superior to placebo in GPP flare prevention, significantly reducing the risk of a GPP flare and flare occurrence over 48 weeks. Given the chronic nature of GPP, a treatment for flare prevention is a significant shift in the clinical approach, and could ultimately lead to improvements in patient morbidity and quality of life.

FUNDING

Boehringer Ingelheim.

Exploring the Clinical Assessment, Guidelines, and Options for the Treatment of Generalized Pustular Psoriasis [Podcast]

Acute episodes of generalized pustular psoriasis (GPP), known as "flares", are characterized by the widespread appearance of pustules with surrounding skin erythema, and are often accompanied by systemic symptoms. The clinical course of GPP is unpredictable, and symptoms vary in extent and severity; the disease may be relapsing-remitting with recurrent episodes of pustulosis, or be more persistent. The triggers that may lead to flares include withdrawal of corticosteroids, stress, pregnancy, and infections. GPP-specific assessment tools, such as the Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) and the General Pustular Psoriasis Area and Severity Index (GPPASI), were developed to evaluate the severity of disease, and to monitor the patient's response to therapy during clinical trials. Spesolimab is the first GPP-specific treatment available in the United States for the treatment of GPP flares in adults, and was approved by the US FDA in September 2022. To date, spesolimab has been approved by regulatory agencies in almost 40 countries, including Japan, Mainland China, and the European Union. Spesolimab is a first-in-class humanized monoclonal antibody that targets the interleukin-36 receptor, and blocks the downstream effects of the interleukin-36 pathway, which is associated with GPP pathogenesis. Data from clinical trials demonstrate the safety and efficacy of spesolimab in providing rapid clinical improvement for patients with GPP flares. Standardized international guidelines for the diagnosis and management of GPP are needed, and no recent GPP guidelines are available in the US. This podcast discusses clinical assessment tools for GPP (GPPGA and GPPASI), the evolution of GPP management guidelines, the therapeutic landscape of GPP, efficacy and safety data for spesolimab, and examines important considerations for patients living with this condition.

A comprehensive overview of psoriatic research over the past 20 years: machine learning-based bibliometric analysis

Background

The surge in the number of publications on psoriasis has posed significant challenges for researchers in effectively managing the vast amount of information. However, due to the lack of tools to process metadata, no comprehensive bibliometric analysis has been conducted.

Objectives

This study is to evaluate the trends and current hotspots of psoriatic research from a macroscopic perspective through a bibliometric analysis assisted by machine learning based semantic analysis.

Methods

Publications indexed under the Medical Subject Headings (MeSH) term "Psoriasis" from 2003 to 2022 were extracted from PubMed. The generative statistical algorithm latent Dirichlet allocation (LDA) was applied to identify specific topics and trends based on abstracts. The unsupervised Louvain algorithm was used to establish a network identifying relationships between topics.

Results

A total of 28,178 publications were identified. The publications were derived from 176 countries, with United States, China, and Italy being the top three countries. For the term "psoriasis", 9,183 MeSH terms appeared 337,545 times. Among them, MeSH term "Severity of illness index", "Treatment outcome", "Dermatologic agents" occur most frequently. A total of 21,928 publications were included in LDA algorithm, which identified three main areas and 50 branched topics, with "Molecular pathogenesis", "Clinical trials", and "Skin inflammation" being the most increased topics. LDA networks identified "Skin inflammation" was tightly associated with "Molecular pathogenesis" and "Biological agents". "Nail psoriasis" and "Epidemiological study" have presented as new research hotspots, and attention on topics of comorbidities, including "Cardiovascular comorbidities", "Psoriatic arthritis", "Obesity" and "Psychological disorders" have increased gradually.

Conclusions

Research on psoriasis is flourishing, with molecular pathogenesis, skin inflammation, and clinical trials being the current hotspots. The strong association between skin inflammation and biologic agents indicated the effective translation between basic research and clinical application in psoriasis. Besides, nail psoriasis, epidemiological study and comorbidities of psoriasis also draw increased attention.