Management of Pustular Psoriasis; The Way Ahead

Pustular psoriasis is a specialized variant of psoriasis which can be life threatening if not treated at the earliest. The pathogenesis has been recently linked to the role of interleukin 36. Apart from the corticosteroids, systemic antipsoriatics like acitretin, cyclosporine and methotrexate have been used with some success though unpredictable. With recent identification of role of IL-36 in the pathogenesis of pustular psoriasis, biologics targeting the IL-36 receptors have been used to manage the situation with high degree of success. This narrative review deals with the recent concepts of pathogenesis of pustular psoriasis as well as the current management scenario.

Human Leukocyte Antigen Markers for Distinguishing Pustular Psoriasis and Adult-Onset Immunodeficiency with Pustular Reaction

Pustular skin diseases, with pustular psoriasis (PP) being the prototype, are immune-mediated diseases characterized by the presence of multiple pustules, resulting from neutrophil accumulation in the layer of epidermis. Sterile skin pustular eruption, like PP, is also observed in 20-30% of patients with adult-onset immunodeficiency syndrome (AOID) and anti-interferon γ autoantibodies (IFN-γ), leading to challenges in classification and diagnosis. While the mechanism underlying this similar phenotype remains unknown, genetic factors in relation to the immune system are suspected of playing an important role. Here, the association between human leukocyte antigen (HLA) genes, which play essential roles in antigen presentation, contributing to immune response, and the presence of skin pustules in AOID and PP was revealed. HLA genotyping of 41 patients from multiple centers in Thailand who presented with multiple sterile skin pustules (17 AOID patients and 24 PP patients) was conducted using a next-generation-sequencing-based approach. In comparison to healthy controls, HLA-B*13:01 (OR = 3.825, 95%CI: 2.08-7.035), C*03:04 (OR = 3.665, 95%CI: 2.102-6.39), and DQB1*05:02 (OR = 2.134, 95%CI: 1.326-3.434) were significantly associated with the group of aforementioned conditions having sterile cutaneous pustules, suggesting a common genetic-related mechanism. We found that DPB1*05:01 (OR = 3.851, p = 0.008) and DRB1*15:02 (OR = 3.195, p = 0.033) have a significant association with pustular reaction in AOID patients, with PP patients used as a control. A variant in the DRB1 gene, rs17885482 (OR = 9.073, p = 0.005), was observed to be a risk factor for PP when using AOID patients who had pustular reactions as a control group. DPB1*05:01 and DRB1*15:02 alleles, as well as the rs17885482 variant in the DRB1 gene, were proposed as novel biomarkers to differentiate PP and AOID patients who first present with multiple sterile skin pustules without known documented underlying conditions.

Generalized pustular psoriasis: A global Delphi consensus on clinical course, diagnosis, treatment goals and disease management

BACKGROUND

Generalized pustular psoriasis (GPP) is a rare and highly heterogeneous skin disease, characterized by flares of neutrophilic pustules and erythema. As a rare disease with few clinical studies and no standardized management approaches, there is a paucity of knowledge regarding GPP.

OBJECTIVES

Conduct a Delphi panel study to identify current evidence and gain advanced insights into GPP.

METHODS

A systematic literature review was used to identify published literature and develop statements categorized into four key domains: clinical course and flare definition; diagnosis; treatment goals; and holistic management. Statements were rated on a Likert scale by a panel of dermatologists in two rounds of online questionnaires; the threshold for consensus was agreement by ≥80%.

RESULTS

Twenty-one panellists reached consensus on 70.9%, 61.8%, 100.0% and 81.8% of statements in the 'clinical course and flare definition', 'diagnosis', 'treatment goals' and 'holistic management of GPP' domains, respectively. There was clear consensus on GPP being phenotypically, genetically and immunologically distinct from plaque psoriasis. Clinical course is highly variable, with an extensive range of complications. Clinical and histologic features supporting GPP diagnosis reached high levels of agreement, and although laboratory evaluations were considered helpful for diagnosis and monitoring disease severity, there was uncertainty around the value of individual tests. All acute and long-term treatment goals reached consensus, including rapid and sustained clearance of pustules, erythema, scaling and crust, clearance of skin lesions and prevention of new flares. Potential triggers, associated comorbidities and differential diagnoses achieved low rates of consensus, indicating that further evidence is needed.

CONCLUSIONS

Global consensus between dermatologists was reached on clinically meaningful goals for GPP treatment, on key features of GPP flares and on approaches for assessing disease severity and multidisciplinary management of patients. On this basis, we present a management algorithm for patients with GPP for use in clinical practice.

An update on therapeutic options for palmoplantar pustulosis: a narrative review and expert recommendations

INTRODUCTION

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease belonging to the localized form of pustular psoriasis. It is characterized by sterile pustule formation in palms and soles and a recurrent disease course. Although we have many treatments for PPP, there is no authoritative guidance.

AREAS COVERED

A thorough search of PubMed was conducted to identify studies in PPP from 1973 onwards, with additional references to specific articles. Any treatment methods were outcomes of interest, including topical treatment, systemic treatment, biologics, other targeted treatments, phototherapy, and tonsillectomy.

EXPERT OPINION

Topical corticosteroids are suggested as first-line therapy. Oral acitretin has become the most applied systemic retinoid recommended in PPP without joint involvement. For patients with arthritis, immunosuppressants like cyclosporin A and methotrexate are more recommended. UVA1, NB-UVB, and 308-nm excimer laser are effective phototherapy options. The combinations of topical or systemic agents and phototherapy may enhance the efficacy, particularly in recalcitrant cases. Secukinumab, ustekinumab, and apremilast are the most investigated targeted therapies. However, heterogeneous reported outcomes in clinical trials provided low-to-moderate quality evidence of their efficacy. Future studies are required to address these evidence gaps. We suggest managing PPP based on the acute phase, maintenance phase, and comorbidities.

Impact of topical emollient, steroids alone or combined with calcipotriol, on the immune infiltrate and clinical outcome in psoriasis

Psoriasis is a chronic inflammatory disease whereby long-term disease control remains a challenge for the patients. Latest evidence suggests that combined topical treatment with steroids and vitamin D analogue foam (Calcipotriol/Betamethasone) is efficient in long-term management of the disease and reducing the number of relapses. Its effects on cellular inflammation and cytokine production remain to be explored. We set out to examine the effect of topical therapies on cellular infiltrate and cytokine profile in the lesional skin of psoriasis patients. This was a monocentric, double-blind, randomized trial with 30 patients. Patients were treated with the combined Calcipotriol/Betamethasone foam, Betamethasone foam alone, Clobetasol Propionate ointment or placebo. 4 mm skin biopsies from lesional and non-lesional sites were taken before and 4 weeks after treatment. Cellular infiltrate, IFNγ and IL-17 were studied by immunofluorescence. Each patient was their own control. Evolution in skin inflammation was studied in parallel with changes in patient's epidermal thickness and their tPASI clinical score. Lesional skin was characterized by increased epidermal thickness, increased number of IL-17 and IFNγ producing CD8+ T cells, NK cells and neutrophils. All treatment reduced epidermal thickness and improved patients tPASI scores. Only the combined Calcipotriol/Betamethasone foam completely abolished epidermal and dermal influx of CD8+ T cells, reduced number of CD8 + IFNγ+ cells (but not CD8 + IL-17+ cells) and significantly reduced the number of MPO+ neutrophils which were predominantly IL-17+. None of the treatments had effect on NK cells. We have shown the combined topical treatment with Calcipotriol/Betamethasone foam to be effective in reducing cellular influx into lesional skin of psoriasis patients and this effect to be superior to emollient or Betamethasone alone. Its previously described efficacy in the clinic may be attributed to its unique and rapid ability to inhibit both adaptive CD8+ T cell and innate immune neutrophilia influx into the skin, which was not observed for the other treatments.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Unconventional treatment options in psoriasis: A review

Psoriasis is a common skin disease that affects 1-3% of the general population. The treatment depends on body surface area involved, quality of life impairment and associated comorbidities. The treatment options include topical therapy, phototherapy, conventional systemic therapy (methotrexate, cyclosporine and acitretin), biologics and oral small molecules (apremilast and tofacitinib). Despite the availability of newer therapies such as biologics and oral small molecules, many a time, there is a paucity of treatment options due to the chronic nature of the disease, end-organ toxicity of the conventional drugs or high cost of newer drugs. In these scenarios, unconventional treatment options may be utilized as stand-alone or adjuvant therapy. In this review, we have discussed these uncommonly used treatment options in the management of psoriasis.

Paradoxical psoriasis in pediatric patients: A systematic review

BACKGROUND

Paradoxical psoriasis occurs in pediatric patients following treatment with biologic agents. These presentations are not well described, and optimal treatment strategies have not been established.

OBJECTIVE

To describe the reported rates, demographic characteristics, clinical presentation, and treatment options for TNF-α inhibitor-induced psoriasis.

METHODS

Systematic review of published cases and cohort studies of paradoxical psoriasis induced by biologic agents, with specific reference to TNF-α inhibitors.

RESULTS

We identified 4564 pediatric patients treated with TNF-α inhibitors, of whom 210 (4.6%) developed paradoxical psoriasis. Infliximab was the drug most likely to induce psoriasis (8.3%), followed by adalimumab (3.3%). Individual-level data were acquired from 129 individuals with a mean age of 13.6 years (SD: 4.0); 45.0% were male. The scalp was the most commonly affected area (47.5%), followed by the ears (30.8%). Most (63.3%) patients were continued on TNF-α inhibitor therapy. Among those who switched TNF-α inhibitors, only 32.0% had complete clearance of their skin lesions. Among patients who were switched to a non-TNF-α inhibitor, 81% had complete clearance of their paradoxical psoriasis.

LIMITATIONS

Data were acquired from retrospective studies including case reports and case series.

CONCLUSION

TNF-α inhibitor-induced psoriasis is a common adverse effect; however, most patients can continue their original therapy and be managed with skin-directed topical or systemic medications. If a patient requires medication discontinuation, switching to a new TNF-α inhibitor is unlikely to lead to resolution of their skin lesions.

Dapsone Ameliorates Colitis through TLR4/NF-kB Pathway in TNBS Induced Colitis Model in Rat

BACKGROUND

Crohn's disease (CD), a type of inflammatory bowel disease (IBD), emerges with severe gastrointestinal (GI) tract inflammation, sometimes known as hostile abdomen. Conventional treatment of CD has several limitations such as insufficient response to treatment, and intolerable side effects of drugs. In addition, the high cost of biologic drugs prevents patients from continuing their treatment. Dapsone showed vigorous anti-inflammatory effects on the skin diseases, lung diseases and inflammatory diseases of the nervous system. Hence, we decided to investigate the effect of dapsone on animal model of CD.

METHODS

In this study, colitis was induced by instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) 100 mg/kg. Rats were treated with daily gavage of dapsone (10, 12.5 and 20 mg/kg). Seven days after induction of colitis, specimens were collected for pathological and molecular assessments.

RESULTS

Dapsone (12.5 and 20 mg/kg) preserved the histologic architecture of the colon and prevented crypts irregularity. Additionally, it decreased tissue edema and hindered inflammatory cells infiltration. Besides, all doses of dapsone decreased tissue concentration of tumor necrosis factor α (TNF-α) and interferon γ (INFγ). Western blot revealed that dapsone could attenuate inflammation via downregulation of toll-like receptor 4 (TLR4) and dephosphorylation of nuclear factor kB (NF-kB).

CONCLUSION

Based on these findings, dapsone attenuates inflammation and decreases TNF-α and INF-γ in animal model of CD. It acts through TLR4/NF-kB pathway to exert these effects.

Development of enzyme linked immunosorbent assay and lateral flow immunoassay for the rapid detection of dapsone in milk

High-throughput rapid detection of dapsone in milk without pretreatment.

Subcorneal pustular dermatosis: Comprehensive review and report of a case presenting during pregnancy

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, relapsing, sterile pustular eruption of unknown etiology that develops most commonly in middle-aged or mature women. This article reviews the presentation, associations, and management of the condition and highlights advances in pathophysiology. Onset of SPD during pregnancy has not been reported. Herein, we report a case of SPD that developed during pregnancy. The patient was treated with dapsone without complications for her or the fetus. An association between T helper (Th) 17 and Th2 environments in the development of SPD has been advocated. Pregnancy is characterized by a predominance of Th2 responses and increased interleukin-17 levels and thus may favor the development of the condition.

Update on the use of dapsone in dermatology

Dapsone (4,4'-diaminodiphenylsulfone) is the only remaining sulfone used in anthropoid therapeutics and is commercially available as an oral formulation, an inhaled preparation, and a 5% or 7.5% cream. Dapsone has antimicrobial effects stemming from its sulfonamide-like ability to inhibit the synthesis of dihydrofolic acid. It also has anti-inflammatory properties such as inhibiting the production of reactive oxygen species, reducing the effect of eosinophil peroxidase on mast cells and down-regulating neutrophil-mediated inflammatory responses. This allows for its use in the treatment of a wide variety of inflammatory and infectious skin conditions. Currently in dermatology, the US Food and Drug Administration (FDA)-approved indications for dapsone are leprosy, dermatitis herpetiformis, and acne vulgaris. However, it proved itself as an adjunctive therapeutic agent to many other skin disorders. In this review, we discuss existing evidence on the mechanisms of action of dapsone, its FDA-approved indications, off-label uses, and side effects.

An update on generalized pustular psoriasis

Introduction: Generalized pustular psoriasis (GPP) is a rare, severe relapsing/remitting, multisystem disease that can be difficult to treat. Recent clinical, histological, and genetic evidence suggests that GPP is a distinct clinical entity from plaque psoriasis and requires a separate diagnosis. The interleukin-36 pathway appears to be central to GPP pathogenesis. As no therapeutic agents have been approved for GPP to date in the United States or Europe, the introduction of anti-IL-36 therapies may change disease management. Areas covered: Using PubMed and Google Scholar, we reviewed the literature for articles related to GPP, psoriasis, and the genetics, pathogenesis, and treatment thereof. Expert opinion: New therapeutic options and updated guidelines for GPP treatment are needed. Ideal agents would have rapid onset of action and rapid time to achieve disease clearance, have the ability to prevent acute flares and avert recurrence, and possess a favorable safety profile. Such therapies should be readily accessible via approval or listing on formularies. Scoring systems to establish GPP disease burden and objective outcome measures could also help with further evaluation of therapies and treatment access issues. IL-36 remains a promising target, as supported by early phase data suggesting efficacy and safety for a novel anti-IL-36 therapy.

Neutrophil Extracellular Traps Induce Human Th17 Cells: Effect of Psoriasis-Associated TRAF3IP2 Genotype

Psoriasis lesions are rich in IL-17-producing T cells as well as neutrophils, which release webs of DNA-protein complexes known as neutrophil extracellular traps (NETs). Because we and others have observed increased NETosis in psoriatic lesions, we hypothesized that NETs contribute to increased T helper type 17 (Th17) cells in psoriasis. After stimulating peripheral blood mononuclear cells with anti-CD3/CD28 beads for 7 days, we found significantly higher percentages of CD3⁺CD4⁺IL-17⁺ (Th17) cells in the presence versus absence of NETs, as assessed by flow cytometry, IL-17 ELISA, and IL17A/F and RORC mRNAs. Memory, but not naïve, T cells were competent and monocytes were required for CD3/CD28-mediated Th17 induction, with or without NETs. Th17 induction was enhanced by the T allele of rs33980500 (T/C), a psoriasis risk-associated variant in the TRAF3IP2 gene encoding the D10N variant of Act1, a key mediator of IL-17 signal transduction. Global transcriptome analysis of CD3/CD28-stimulated peripheral blood mononuclear cells by RNA sequencing confirmed the stimulatory effects of NETs, demonstrated NET-induced enhancement of cytokine gene expression, and verified that the effect of Act1 D10N was greater in the presence of NETs. Collectively, these results implicate NETs and the Act1 D10N variant in human Th17 induction from peripheral blood mononuclear cells, with ramifications for immunogenetic studies of psoriasis and other autoimmune diseases.

TNF Inhibitor-Induced Psoriasis: Proposed Algorithm for Treatment and Management

Tumor necrosis factor a (TNF-α)-targeted therapies have expanded the therapeutic options for patients with inflammatory bowel disease (IBD), rheumatoid arthritis (RA), psoriasis, and psoriatic arthritis (PsA) and have significantly improved patients' quality of life. Paradoxically, anti-TNF-α agents may induce psoriatic eruptions or worsen preexisting psoriatic skin disease. Currently, there is no standard approach for the management of TNF inhibitor-induced psoriasis. Here, we conduct a literature review on TNF inhibitor-induced psoriasis and introduce a novel treatment algorithm for maintaining otherwise effective anti-TNF therapy versus switching to a different class as appropriate in the management of patients with IBD, RA, psoriasis, or PsA.

Underdiagnosed and undertreated psoriasis: Nuances of treating psoriasis affecting the scalp, face, intertriginous areas, genitals, hands, feet, and nails

Psoriasis of the scalp, face, intertriginous areas, genitals, hands, feet, and nails is often underdiagnosed, and disease management can be challenging. Despite the small surface area commonly affected by psoriasis in these locations, patients have disproportionate levels of physical impairment and emotional distress. Limitations in current disease severity indices do not fully capture the impact of disease on a patient's quality of life, and, combined with limitations in current therapies, many patients do not receive proper or adequate care. In this review, we discuss the clinical manifestations of psoriasis in these less commonly diagnosed areas and its impact on patient quality of life. We also examine clinical studies evaluating the effectiveness of therapies on psoriasis in these regions. This article highlights the need to individualize treatment strategies for psoriasis based on the area of the body that is affected and the emerging role of biologic therapy in this regard.

Systemic Monotherapy Treatments for Generalized Pustular Psoriasis: A Systematic Review

Generalized pustular psoriasis (GPP) is a rare but serious and difficult to treat cutaneous disease, with high morbidity and mortality rates. Despite the numerous treatment regimens available, the overall quality of evidence-based research is limited with a lack of an algorithmic approach available. In this review, we aim to evaluate the current level of evidence regarding the efficacy and safety/tolerability of systemic monotherapies available in the treatment of GPP. A comprehensive MEDLINE, EMBASE, and PubMed search of clinical studies examining systemic monotherapy treatment options for GPP was conducted. In total, 31 studies met eligibility criteria. Described treatment modalities included retinoids, cyclosporine, biologics, and dapsone. Despite the lack of high-quality evidence or a well-accepted treatment algorithm for GPP, systemic retinoids, cyclosporine, biologics, and dapsone are all possible first-line agents, with retinoids being one of the best-supported treatment options and biologics as an emerging therapeutic field with great potential requiring additional data. However, the final choice of treatment should be considered within the unique context of each patient.

Subcorneal Pustular Dermatosis: A Review of 30 Years of Progress

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, benign yet relapsing pustular dermatosis. Its incidence and prevalence have not been well studied. It characteristically presents as hypopyon pustules on the trunk and intertriginous areas of the body. SPD is similar to two other disease entities. Both SPD-type immunoglobulin (Ig)-A pemphigus and annular pustular psoriasis clinically and histologically present similarly to SPD. Immunologic studies separate SPD-type IgA pemphigus from SPD and pustular psoriasis. However, there is still an unclear designation as to whether SPD is its own entity distinct from pustular psoriasis, as the once thought characteristic histologic picture of psoriasis does not hold true for pustular psoriasis. SPD has been reported to occur in association with several neoplastic, immunologic, and inflammatory conditions. Dapsone remains the first-line treatment for SPD, although dapsone-resistant cases have been increasingly reported. Other therapies have been used singly or as adjunctive therapy with success, such as corticosteroids, immunosuppressive agents, tumor necrosis factor inhibitors, and ultraviolet light therapy. This article provides a review of the last 30 years of available literature, with a focus on successful treatment options and a suggestion for reappraisal of the classification of SPD.