Topical, systemic and biologic therapies in hidradenitis suppurativa: pathogenic insights by examining therapeutic mechanisms

Host immunity and intracellular bacteria evasion mechanisms: Enhancing host-directed therapies with drug delivery systems

Host-directed therapies (HDTs) have been investigated as a potential solution to combat intracellular and drug-resistant bacteria. HDTs stem from extensive research on the intricate interactions between the host and intracellular bacteria, leading to a treatment approach that relies on immunoregulation. To improve the bioavailability and safety of HDTs, researchers have utilized diverse drug delivery systems (DDS) to encapsulate and transport therapeutic agents to target cells. In this review, we first introduce the three mechanisms of bactericidal action and intracellular bacterial evasion: autophagy, reactive oxygen species (ROS), and inflammatory cytokines, with a particular focus on autophagy. Special attention is given to the detailed mechanism of xenophagy in clearing intracellular bacteria, a crucial selective autophagy process that specifically targets and degrades intracellular pathogens. Following this, we present the application of DDS to modulate these regulatory methods for intracellular bacteria elimination. By integrating insights from immunology and nanomedicine, this review highlights the emerging role of DDS in advancing HDTs for intracellular bacterial infections and paving the way for innovative therapeutic interventions.

Metabolic syndrome and dermatological diseases: association and treatment

Metabolic syndrome (MetS) is a clinical syndrome associated with cardiovascular disease, diabetes, obesity, and dyslipidemia. Its primary features include dyslipidemia, hypertension, abdominal obesity, and insulin resistance (IR). Recently, research has revealed that MetS is not only a manifestation of internal metabolic disturbances but is also closely associated with various dermatological conditions, including inflammatory skin diseases, autoimmune skin diseases, and skin tumors. These studies have clarified the complex mechanisms underlying the interaction between MetS and these skin diseases, including IR, chronic inflammatory responses, and oxidative stress. This review summarizes the association between MetS and related dermatological conditions and their shared physiological mechanisms. It aims to provide clinicians with new therapeutic strategies and preventive measures to improve the treatment outcomes and quality of life of patients with skin conditions.

Addressing the Dressings: Wound Care in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) wounds are complex and have unique characteristics that complicate dressing selection. Proper wound care assists with wound healing and contributes to improved quality of life. Ideal dressings are comfortable while maintaining a wound-healing environment. Antimicrobial dressings should target dysbiosis and biofilms. Absorptive dressings are needed for control of exudate. Pain control is best achieved with nonadhesive dressings and contact layers. Agents targeting anaerobic bacteria are effective at odor reduction. Surgery may be indicated for management of refractory wounds. Overall, there is a need for increased research and education on both routine and postsurgical wound care in HS.

Human papillomavirus infection is associated with increased risk of new-onset hidradenitis suppurativa: A population-based cohort study

BACKGROUND

The exact cause of hidradenitis suppurativa (HS) remains unclear, although emerging research suggests a link between infectious agents and inflammatory skin diseases. The association between human papillomavirus (HPV) infection and HS development, however, has not been studied.

OBJECTIVE

The objective of this study was to evaluate the risk of incident HS in patients with HPV infection.

METHODS

Using the TriNetX research network, we conducted a retrospective cohort study of patients diagnosed with HPV and matched controls. Propensity score matching adjusted for variables like age, sex (male/female), race, body mass index, comorbidities, and lifestyle factors. The primary outcome was new-onset HS, analyzed across demographic and clinical factors. Hazard ratios with 95% confidence intervals were calculated to assess the risk.

RESULTS

After matching, both the HPV and control cohorts included 582,007 patients. HPV-infected individuals had a significantly higher risk of developing HS (hazard ratio: 1.356, 95% confidence interva: 1.290-1.427). This increased risk was consistent across various demographic and clinical groups. Sensitivity analyses confirmed the robustness of these findings.

LIMITATIONS

Retrospective cohort design.

CONCLUSIONS

HPV infection is linked to a higher risk of HS, suggesting a potential association. Further research is required to validate these results and assess their impact in different populations and clinical settings, as well as also elucidate the potential impact of other infections involved in the pathogenesis of HS.

Efficacy of Strontium Cream in Alleviating Pruritus in Hidradenitis Suppurativa

Objective

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition with limited treatment options and a significant impact on quality of life. This prospective, open-label, real-world study aimed to evaluate the efficacy of strontium cream in alleviating pruritus in HS.

Methods

Fifty participants completed baseline and one-week post-intervention surveys. Pruritus was assessed using a numeric severity scale and a qualitative survey on overall itch reduction.

Results

Statistical analysis revealed a significant reduction in itching symptoms post-intervention, with mean itch scores decreasing from 3.80±0.90 at baseline to 2.28±1.50 post-intervention (p<0.001). Participant feedback also indicated overall satisfaction, with 84 percent of participants willing to recommend the cream to other HS patients.

Limitations

The study relied on self-reported data, which introduces subjectivity, and the absence of a control group limits causal inference.

Conclusion

Strontium cream demonstrates promise as a therapeutic option for managing pruritus in HS, warranting further research.

Unlocking the Mechanisms of Hidradenitis Suppurativa: Inflammation and miRNA Insights

Inflammatory skin diseases impose a significant burden on patients and healthcare systems worldwide. Among these, hidradenitis suppurativa (HS) is particularly notable for its chronic and recurrent nature. Recurrent nodules, abscesses, and scarring in apocrine gland-rich areas characterize the disease, including the groin, axillae, and perianal regions. Despite its considerable physical and psychological impact, the precise mechanisms driving HS remain elusive. Recent advancements in understanding the inflammatory processes involved in HS have highlighted the TNF-alpha, IL-1β, and IL-17/IL-23 pathways, which play crucial roles in initiating and perpetuating the disease. Moreover, specific microRNAs (miRNAs), such as miR-24-1-5p, miR146a-5p, mirR-26a-5p, miR-206, miR-338-3p, and miR-338-5p, are involved in these inflammatory processes. Dysregulation of these miRNAs contributes to aberrant cytokine expression and persistent inflammation, foreseeably exacerbating HS disease progression. This narrative review hypothesizes that miRNA dysregulation triggers aberrant expression in specific inflammatory pathways, contributing to HS's clinical manifestations and progression. We explore the implicated miRNAs' potential as biomarkers for earlier disease detection and as novel therapeutic targets. Identifying miRNA dysregulation offers new opportunities for earlier and more accurate diagnosis, potentially allowing clinicians to intervene before severe disease manifestations occur. Furthermore, therapeutic strategies to modulate miRNA expression could target the inflammatory pathways driving HS, leading to more personalized and effective treatments. This review also discusses future research directions to enhance the clinical management of HS. A better understanding of miRNA involvement in HS offers new avenues for research and management, ultimately improving patient outcomes and quality of life.

Report of successful treatment of follicular occlusion triad with adalimumab and research progress on biologic therapy for follicular occlusion triad

Purpose: This article aims to present a case report of a patient with Follicular occlusion triad (FOT) who achieved successful disease control with adalimumab combined with isotretinoin and provide a comprehensive review of the current research progress on biologic therapies for FOT.

Methods: We report a case of a 22-year-old female patient diagnosed with FOT, who was treated with adalimumab combined with isotretinoin after failing to respond to conventional therapies. A systematic literature review was conducted to summarize the current research progress on biologic therapies for FOT, including TNF-α inhibitors, IL-17 inhibitors, IL-12/IL-23 inhibitors, IL-23 inhibitors, IL-1 inhibitors, and other novel biologic agents.

Results: The patient achieved significant improvement in skin lesions, pain, and quality of life after three months of treatment with adalimumab combined with isotretinoin, without experiencing severe adverse reactions. The literature review revealed that adalimumab and secukinumab are the two FDA-approved biologics for FOT, while others, such as bimekizumab, infliximab, anakinra, and bermekimab, have shown promise in clinical studies.

Conclusions: Biologic therapies have revolutionized FOT management, providing effective options for patients unresponsive to conventional treatments. As our understanding of FOT pathogenesis and the mechanisms of action of biologics grows, further advancements in biologic therapies for FOT are expected.

Taiwanese Dermatological Association (TDA) consensus recommendations for the definition, classification, diagnosis, and management of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory follicular disease characterized by painful, recurrent, inflamed lesions most commonly occurring in the axillary, inguinal, and anogenital regions. HS can inflict immense physical and psychological impact on patients who suffer from this distressing disease. Management of HS generally requires combining various medical and procedural treatment modalities; however, the disease is often recalcitrant to conventional treatments. In light of recent evidence supporting the effectiveness of biologic agents in the treatment of HS, the Taiwanese Dermatological Association established an expert panel of nine dermatologists to develop consensus statements aimed to provide up-to-date evidence-based guidance in optimizing HS patient management in Taiwan. The recommendations described in the statements were summarized in a management algorithm in terms of general care, topical treatment, systemic treatment, and procedural treatment.

Inflammasomes: emerging therapeutic targets in hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent inflammatory lesions, which affect skin and hair follicles in intertriginous areas. HS has a multifactorial aetiology resulting in barrier dysfunction associated with aberrant immune activation. There is increased evidence for the role of inflammasomes in the pathophysiology of inflammatory skin diseases, including HS. Inflammasomes are multiprotein complexes activated following exposure to danger signals, including microbial ligands and components of damaged host cells. Inflammasome activation induces many signalling cascades and subsequent cleavage of proinflammatory cytokines - most notably interleukin (IL)-1β - which have a role in HS pathogenesis. Limited immunotherapies are approved for treating moderate-to-severe HS, with variable response rates influenced by disease heterogeneity. Inflammasomes represent attractive targets to suppress multiple inflammatory pathways in HS, including IL-1β and IL-17. This review aims to summarize the role of inflammasomes in HS and to evaluate evidence for inflammasomes as therapeutic targets for HS treatment.

Essentials of hidradenitis suppurativa: a comprehensive review of diagnostic and treatment perspectives

Hidradenitis suppurativa, or acne inversa, is a chronic inflammatory skin condition with recurrent inflammatory nodules, abscesses, subcutaneous tracts, and scars. This condition may cause severe psychological distress and reduce the quality of life for affected individuals. It is considered to have one of the most damaging effects on quality of life of any skin disorder as a result of the discomfort and foul-smelling discharge from these lesions. Although the pathophysiology of HS is still unclear, multiple factors, including lifestyle, genetic, and hormonal factors, have been associated with it. The pathogenesis of HS is very complex and has wide clinical manifestations; thus, it is quite challenging to manage and often requires the use of combination treatments that must be tailored according to disease severity and other patient-specific factors. Although lifestyle changes, weight loss, quitting smoking, topical treatments, and oral antibiotics are adequate for mild cases, the challenge for healthcare professionals is dealing with moderate-to-severe HS, which often does not respond well to traditional approaches. This literature review, consisting of an overview of the various assessment tools and therapy strategies available for the diagnosis and treatment of HS from published literature, aims to be a guide for practicing clinicians in dealing with the complexities associated with this disease.

S2k‐Leitlinie zur Therapie der Hidradenitis suppurativa/Acne inversa – Kurzfassung

Die S2k‐Leitlinie der Hidradenitis suppurativa/Acne inversa (HS/AI) soll eine akzeptierte Entscheidungshilfe für die Auswahl/Durchführung einer geeigneten/suffizienten Therapie liefern. Hidradenitis suppurativa/Acne inversa ist eine chronisch‐rezidivierende, entzündliche, potenziell mutilierende Hauterkrankung des terminalen Haartalgdrüsenapparats, mit schmerzhaften, entzündlichen Läsionen in den apokrinen drüsenreichen Körperregionen. Ihre Punktprävalenz in Deutschland ist 0,3%, sie wird mit einer Verspätung von 10,0 ± 9,6 Jahren diagnostiziert. Abnormale Differenzierung der Keratinozyten des Haartalgdrüsenapparats und eine begleitende Entzündung bilden die zentrale pathogenetische Grundlage. Primäre HS/AI‐Läsionen sind entzündliche Knoten, Abszesse und drainierende Tunnel. Rezidive in den letzten 6 Monaten mit mindestens zwei Läsionen an den Prädilektionsstellen verweisen auf eine HS/AI mit einer 97‐prozentigen Genauigkeit. HS/AI‐Patienten leiden an einer deutlichen Einschränkung der Lebensqualität. Zur korrekten Therapieentscheidung sollen Klassifikation und Aktivitätsbewertung mit einem validierten Instrument erfolgen, wie dem International Hidradenitis Suppurativa Severity Scoring System (IHS4). Hidradenitis suppurativa/Acne inversa wird nach der Ausprägung der nachweisbaren Entzündung in zwei Formen eingeteilt: aktive, entzündliche (milde, mittelschwere und schwere nach IHS4) und vorwiegend inaktive, nicht entzündliche (Hurley‐Grad‐I, ‐II und ‐III) HS/AI. Orale Tetrazykline oder eine 5‐tägige intravenöse Therapie mit Clindamycin sind mit der Effektivität von Clindamycin/Rifampicin vergleichbar. Subkutan applizierbares Adalimumab, Secukinumab und Bimekizumab sind für die Therapie der HS/AI zugelassen. Für die vorwiegend nicht entzündliche Erkrankungsform stehen verschiedene operative Verfahren zur Verfügung. Medikamentöse/chirurgische Kombinationen gelten als ganzheitliches Therapieverfahren.

Causal relationship between gut microbiota and hidradenitis suppurativa: a two-sample Mendelian randomization study

Background

Accumulating evidence suggests that alterations in gut microbiota composition are associated with the hidradenitis suppurativa (HS). However, the causal association between gut microbiota and HS remain undetermined.

Methods

We performed a bidirectional two-sample Mendelian randomization (MR) analysis using genome-wide association study summary data of gut microbiota and hidradenitis suppurativa from the MiBioGen consortium which concluded 18,340 individuals analyzed by the MiBioGen Consortium, comprising 211 gut microbiota. HS data were acquired from strictly defined HS data collected by FinnGenbiobank analysis, which included 211,548 European ancestors (409 HS patients, 211,139 controls). The inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model, weighted median, and MR-Egger were used to determine the changes of HS pathogenic bacterial taxa, followed by sensitivity analysis including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association and the leave-one-out method assessed the reliability of the results. Additionally, a reverse MR analysis was carried out to seek for possible reverse causality.

Results

By combining the findings of all the MR steps, we identified four causal bacterial taxa, namely, Family XI, Porphyromonadaceae, Clostridium innocuum group and Lachnospira. The risk of HS might be positively associated with a high relative abundance of Clostridium innocuum group (Odds ratio, OR 2.17, p = 0.00038) and Lachnospira (OR 2.45, p = 0.017) but negatively associated with Family XI (OR 0.67, p = 0.049) and Porphyromonadaceae (OR 0.29, p = 0.014). There were no noticeable outliers, horizontal pleiotropy, or heterogeneity. Furthermore, there was no proof of reverse causation found in the reverse MR study.

Conclusion

This study indicates that Clostridium innocuum group and Lachnospira might have anti-protective effect on HS, whereas Family XI and Porphyromonadaceae might have a protective effect on HS. Our study reveals that there exists a beneficial or detrimental causal effect of gut microbiota composition on HS and offers potentially beneficial methods for therapy and avoidance of HS.

The ameliorative effects of topical gemifloxacin alone or in combination with clobetasol propionate on imiquimod-induced model of psoriasis in mice

Psoriasis is a lifelong immune-driven skin condition characterized by excessive epidermal overgrowth and inflammatory cell infiltration. Gemifloxacin is a fourth-generation fluoroquinolone with improved immunomodulatory and anti-inflammatory properties that are believed to possess an attractive role in psoriasis via suppressing the production of cytokines, chemokines, and eosinophil and neutrophil chemotaxis. The aim of this research is to investigate the ameliorative effects of prolonged topical gemifloxacin (GMF) alone and combined with clobetasol propionate (CLO) on an imiquimod (IMQ)-induced mouse model of psoriasis. Forty-eight Swiss albino mice were divided into six groups of eight. All groups except the negative controls got 62.5 mg of IMQ 5% topically for 8 days. Mice in the control group (controls) got Vaseline instead. Following the induction in the IMQ 5% group, mice in treatment groups CLO 0.05, GMF 1%, GMF 3%, and CLO + GMF obtained clobetasol propionate 0.05%, GMF 1% and 3%, and a combination of both, respectively, for an additional 8 days, rendering the experiment 16 days long. Our results revealed that gemifloxacin alleviated erythematous, thickened, and scaly psoriatic lesions and inhibited the tissue level of inflammatory cytokines, including interleukin (IL)-8, IL-17A, IL-23, tumor necrosis factor-α (TNF-α), and transforming growth factor-β1 (TGF-β1). The anti-inflammatory effect also occurred by hindering nuclear factor-kappa B (NF-κB) signaling and reversing histopathological problems. Gemifloxacin acts effectively in mitigating psoriasis-associated lesions and restricting NF-κB-mediated inflammation, recommending gemifloxacin as a promising adjuvant candidate for additional studies on the long-term treatment of autoimmune and autoinflammatory dermatoses like psoriasis.

The Pathogenesis and Treatment of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a multifactorial disease involving the skin and subcutaneous tissues characterized by deep-seated, painful nodules and abscesses with draining sinus tracts. It affects mostly younger individuals between the ages of 18 and 34. The discomfort and embarrassment that patients affected by HS experience negatively impact their daily lives. It is associated with decreased quality of life and high rates of comorbid depression and anxiety. The rate of depression in HS was reported to be as high as 26%. Its pathogenesis is multifactorial and as such requires a multimodal approach to treatment, which subsequently is reviewed here. Moreover, the pathogenesis of HS is complex and only partially understood. Autoinflammation is the key driver of disease development and is linked with dysregulated inflammasome activation with the subsequent production of inflammatory cytokines. Genetics and cutaneous microbiome play a role in the development of chronic inflammation and lesion formation. Risk factors such as obesity, metabolic syndrome, diabetes, and smoking also add to the systemic inflammation. Targeting these risk factors is a key aspect of the treatment of HS. Lifestyle modifications are used in conjunction with pharmacotherapy and procedures to effectively manage the disease.

Hidradenitis Suppurativa in Children and Adolescents: An Update on Pharmacologic Treatment Options

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin condition that manifests as painful, deep-seated, inflamed nodules and abscesses in the axillary, groin, perianal, perineal, and inframammary regions. The associated pain, malodour, and disfigurement contribute to its profound negative impact on psychosocial spheres and overall quality of life in affected individuals. Although the symptoms of HS classically begin in the second or third decade of life, HS affects children and adolescents as well. Despite this, there are limited pediatric data on treatment, which are largely based on expert opinion, extrapolation of efficacy data in adults with HS, and safety information from medication use in other pediatric diseases. On this basis, there exist several pharmacological modalities in the treatment of children and adolescents with HS including topical therapies, systemic therapies, and biologics. The goals of this review article are to: (1) review the efficacy of different pharmacological treatment modalities in children and adolescents with HS, and (2) review the safety and monitoring considerations of the different treatment options in children and adolescents with HS.

Efficacy of medical treatments for pediatric hidradenitis suppurativa: A systematic review

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition that has been insufficiently studied in the pediatric population. Timely and effective medical treatments may improve quality of life, mitigate disease burden, and prevent the need for invasive procedural interventions such as surgical excisions. However, there is a paucity of research on the efficacy of medical management strategies for HS in children and adolescents. The aim of this study was to perform a systematic review of the literature on the efficacy and safety of medical treatments for HS in patients <18 years of age. In April 2022, MEDLINE and EMBASE databases were searched for articles on the efficacy of medical treatments for HS in the pediatric population. Between 1984 and 2022, 35 articles (101 patients) met the inclusion criteria. Most patients had Hurley Stage II disease (46.7%, 35/75) followed by Stage I (36%, 27/75), and Stage III (17.3%, 13/75). 100% (23/23) of patients responded to antibiotics, 100% (8/8) to finasteride, 93.9% (31/33) to biologics, 80% (4/5) to oral retinoids, and 50% (6/12) to metformin. Overall, this study demonstrates that medical treatment regimens can improve HS symptoms in pediatric patients, but the extent of improvement is unclear, and the results were largely based on case reports or case series. Prospective studies are warranted to better understand the efficacy and safety of medical treatments for pediatric HS. Clinical trials of HS therapies need to be inclusive of pediatric patients to help define the optimal timing of treatment initiation and guide patient selection.

Skin and Gut Microbiome in Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic skin disease that significantly impairs the quality of life of affected individuals. The disease is characterized by persistent purulent lesions in specific anatomical areas, and its pathophysiology involves multiple factors, including inflammation, genetics, the microbiome, and environmental components. Recent research suggests a potential role for pathogenic bacteria in HS, highlighting the importance of the communication between the human host and the microbiome in maintaining homeostasis and immune system reactivity. However, the exact mechanisms underlying the gut-skin microbial interactions in HS remain unclear. This systematic review aims to examine the existing literature on the differences in skin and gut microbiome composition between HS patients and healthy controls. The review identifies methodological inconsistencies and calls for further research to elucidate the microbiome's role in HS pathogenesis and to explore new therapeutic interventions. The review highlights the need for advancements in microbiome research methodologies, such as metataxonomics and metagenomics, to improve our understanding of the microbiota's impact on health and disease.

Modulation of Disease-Associated Pathways in Hidradenitis Suppurativa by the Janus Kinase 1 Inhibitor Povorcitinib: Transcriptomic and Proteomic Analyses of Two Phase 2 Studies

Janus kinase (JAK)/signal transducer and activator of transcription signaling (STAT) has been implicated in the pathophysiology of hidradenitis suppurativa (HS). This study evaluated treatment-related transcriptomic and proteomic changes in patients with moderate-to-severe HS treated with the investigational oral JAK1-selective inhibitor povorcitinib (INCB054707) in two phase 2 trials. Lesional skin punch biopsies (baseline and Week 8) were taken from active HS lesions of patients receiving povorcitinib (15 or 30 mg) once daily (QD) or a placebo. RNA-seq and gene set enrichment analyses were used to evaluate the effects of povorcitinib on differential gene expression among previously reported gene signatures from HS and wounded skin. The number of differentially expressed genes was the greatest in the 30 mg povorcitinib QD dose group, consistent with the published efficacy results. Notably, the genes impacted reflected JAK/STAT signaling transcripts downstream of TNF-α signaling, or those regulated by TGF-β. Proteomic analyses were conducted on blood samples obtained at baseline and Weeks 4 and 8 from patients receiving povorcitinib (15, 30, 60, or 90 mg) QD or placebo. Povorcitinib was associated with transcriptomic downregulation of multiple HS and inflammatory signaling markers as well as the reversal of gene expression previously associated with HS lesional and wounded skin. Povorcitinib also demonstrated dose-dependent modulation of several proteins implicated in HS pathophysiology, with changes observed by Week 4. The reversal of HS lesional gene signatures and rapid, dose-dependent protein regulation highlight the potential of JAK1 inhibition to modulate underlying disease pathology in HS.

Pharmacology of orismilast, a potent and selective PDE4 inhibitor

BACKGROUND

There remains an unmet need for oral medications that are safe and efficacious for long-term management of chronic inflammatory skin diseases (CISD). Inhibition of phosphodiesterase 4 (PDE4) can modulate a broad range of pro-inflammatory cytokines that play a major role in CISD pathogenesis. Orismilast is a second generation PDE4 inhibitor in clinical development for CISD treatment.

OBJECTIVES

The objective of this study was to examine the PDE4 enzymatic activity and anti-inflammatory effects of orismilast in vitro, ex vivo, and in vivo.

METHODS

The PDE1-11 enzymatic activity of orismilast was tested in vitro using a single concentration of 308 nM orismilast. The PDE4 selectivity and inhibitory potency was further examined in a radiometric assay. Orismilast was tested on human whole blood and human peripheral blood mononuclear cells (PBMC) to determine effects on its cytokine secretion and inhibition profile ex vivo. Orismilast was orally administered in a murine model of chronic oxazolone-induced ear skin inflammation. Ear thickness, a marker of inflammation, and inflammatory cytokines were analysed.

RESULTS

Orismilast selectively inhibited PDE4 and demonstrated potent inhibition of PDE4B and PDE4D subtype splice variants in vitro. Orismilast inhibited whole blood and PBMC production of tumour necrosis factor α (TNFα), and the secretion of T-helper (Th)1 (TNFα and IFNγ), Th17 (IL-22 and IL-23), and Th2 (IL-4, IL-5, and IL-13) related cytokines in PBMC. In vivo, 10 and 30 mg/kg doses of orismilast significantly reduced ear thickness and inflammation markers (p < 0.0001, respectively).

CONCLUSION

Orismilast displayed selective and potent PDE4 inhibition and broad-spectrum anti-inflammatory activity in several pre-clinical models. The results of the study support clinical development of oral orismilast as a novel treatment option for CISD including psoriasis, atopic dermatitis, and hidradenitis suppurativa.

Efficacy of Subantimicrobial, Modified-Release Doxycycline Compared to Regular-Release Doxycycline for the Treatment of Hidradenitis Suppurativa

Introduction

Antibiotics are frequently used to treat hidradenitis suppurativa (HS), but the evidence-based literature available on their use is limited. Considering that HS is not primarily an infectious disease, we sought to evaluate the efficacy of subantimicrobial, modified-release doxycycline (MR-DC) compared to regular-release doxycycline (RR-DC) for the treatment of HS.

Materials and Methods

Patients were randomly assigned to receive treatment with either MR-DC 40 mg once daily or RR-DC 100 mg twice daily for a period of 12 weeks. The treatment efficacy was assessed after 12 weeks of treatment using the International Hidradenitis Suppurativa Severity Score System (IHS4), the Dermatology Life Quality Index (DLQI), and the Hidradenitis Suppurativa Clinical Response (HiSCR).

Results

A total of 49 patients (25 in the MR-DC group and 24 in the RR-DC group) were included in the study. A statistically significant (p < 0.05) reduction of IHS4 and DLQI was observed in both groups at week 12. HiSCR was achieved by 64% of patients receiving MR-DC and 60% of those receiving RR-DC.

Conclusion

MR-DC demonstrated comparable efficacy to RR-DC in the treatment of HS. MR-DC may serve as a valuable alternative to other antibiotic regimes, considering its anti-inflammatory properties and its lower potential to induce antibiotic resistance.

Practical Guidelines for Managing Patients With Hidradenitis Suppurativa: An Update

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease that is characterized by the formation of comedones, papules, nodules, abscesses and sinus tracts in the axillary, inframammary, groin, and gluteal areas. Up to 3.8% of the Canadian population has HS, though due to a lack of awareness of HS, many patients are initially misdiagnosed and do not receive adequate treatment early on in the disease course. Once a diagnosis of HS is made, developing an effective management plan can be a dilemma for many providers. There is significant variability in response to any given therapy within the HS patient population and many HS patients have other medical comorbidities which must be taken into consideration. The aim of this review is to provide a practical approach for all healthcare providers to diagnose and manage HS and its associated comorbidities. A sample electronic medical record template for HS management was developed by the Canadian Hidradenitis Suppurativa Foundation Executive Board and is intended for use in clinical settings. This will help to increase collaboration between primary healthcare providers, dermatologists, and other medical specialists and ultimately improve the quality of care that HS patients receive.

High inflammation in hidradenitis suppurativa extends to perilesional skin and can be subdivided by lipocalin-2 expression

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease presenting with diverse manifestations ranging from nodules and abscesses to draining tunnels. Whether the underlying inflammation from lesions extends to relatively healthy-appearing adjacent perilesional and distant nonlesional skin has not been systematically evaluated.

OBJECTIVE

We sought to characterize lesional, perilesional, and nonlesional skin in patients with HS.

METHODS

Skin biopsy samples were collected under ultrasound guidance from patients with active, untreated moderate-to-severe HS. Site-matched control biopsy samples from healthy volunteers were used for comparison.

RESULTS

RNA sequencing demonstrated that HS skin clustered separately from healthy control skin, with perilesional and lesion skin clustering together and away from nonlesional skin. Immunohistochemistry analysis identified psoriasiform hyperplasia with keratin 16 positivity in both perilesional and lesional skin, with comparable levels of CD3+, CD11c+, and neutrophil elastase-positive cellular infiltration. There was a marked upregulation of IL-17 signaling in perilesional and lesional skin. HS samples clustered on the basis of expression of lipocalin-2 (LCN2), with samples characterized by high LCN2 expression in the skin exhibiting a differing transcriptomic profile with significantly higher overall inflammation than that of skin characterized by low LCN2 levels.

CONCLUSIONS

Perilesional HS skin has a transcriptomic and molecular profile comparable to that of lesional skin. HS can be grouped into 2 distinct subtypes based on molecular levels of LCN2 in the skin, with the LCN2-high subtype exhibiting an overall higher inflammatory burden and an upregulation of targetable cytokines. To our knowledge, this is the first study to characterize a unique HS subtype (and a potential endotype) that may guide future therapeutic targets.

Hidradenitis Suppurativa: Host-Microbe and Immune Pathogenesis Underlie Important Future Directions

Hidradenitis suppurativa (HS) is an inflammatory disease of the skin with a chronic, relapsing-remitting course. The pathogenesis of the disease is poorly understood and involves multiple factors, including genetics, environment, host-microbe interactions, and immune dysregulation. In particular, the composition of the cutaneous microbiome shifts as the disease progresses, although it is unclear whether this is a primary or secondary process. Trials with immunomodulatory therapy elucidate the role of specific immune pathways and cytokine signaling in disease mechanism, such as TNF-α, IL-1β, IL-12, IL-17, IL-23, and complement. Future studies should continue examining the causes of and contributing factors to microbial changes and immune dysregulation in HS pathogenesis.

The Clinical Relevance of the Microbiome in Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa is a chronic disease of the pilosebaceous unit. The name of the condition is a testament to the presumed relationship between the disease and the microbiome. The pathophysiology of hidradenitis suppurativa is, however, complex and believed to be the product of a multifactorial interplay between the interfollicular epithelium, pilosebaceous unit, microbiome, as well as genetic and environmental factors. In this review we assimilate the existing literature regarding the role played by the human microbiome in HS in various contexts of the disease, including the pathophysiologic, therapeutic, and potentially, diagnostic as well prognostic. In conclusion, the role played by the microbiome in HS is extensive and relevant and can have bench-to-bedside applications.

Hidradenitis suppurativa: A folliculotropic disease of innate immune barrier dysfunction?

The innate immune system of human skin consists of a multi-layered barrier consisting of cells and soluble effector molecules charged with maintaining homeostasis and responding to insults and infections. It has become increasingly clear that these barrier layers become compromised in skin diseases, especially in disorders of an (auto)inflammatory nature. In the case of hidradenitis suppurativa, great strides have been made in recent years in characterizing the underlying breakdown in homeostatic innate immunity, including an increasing understanding of the central role of the hair follicle in this process. This breakdown appears to occur at multiple levels: the pilosebaceous unit, associated epithelium, the cutaneous microbiome, alteration of immune cell function and local molecular events such as complement activation. This review seeks to summarize, contextualize and analyse critically our current understanding of how these innate immune barriers become dysregulated in the early stage(s) of hidradenitis suppurativa, and to speculate on where potential hidradenitis suppurativa research could be most fruitful.

Development of In-Situ Spray for Local Delivery of Antibacterial Drug for Hidradenitis Suppurativa: Investigation of Alternative Formulation

Hidradenitis suppurativa (HS) has been considered an orphan disease with limited treatments available. The available topical treatment for this condition is clindamycin lotion; however, short retention and frequent application are the main setbacks. Thus, the present study aimed to attain an optimized antibacterial in situ spray formulation for the hidradenitis suppurativa skin condition, which gels once in contact with the skin surface at around 37 °C and possesses bioadhesion as well as sustained-release properties of the incorporated drug. Different concentrations of thermo-reversible gelling polymer, Pluronic F-127, were investigated along with the selected bioadhesive polymers, HPMC and SA. The optimized formulation F3 consisting of 18% Pluronic F-127 with 0.2% HPMC and 0.2% SA was characterized based on various physicochemical properties. The gelation temperature of F3 was found to be 29.0 ± 0.50 °C with a gelation time of 1.35 ± 0.40 min and a pH of 5.8. F3 had the viscosity of 178.50 ± 5.50 cP at 25 °C and 7800 ± 200 cP at 37 °C as the gel set. The optimized formulation was found to be bioadhesive and cytocompatible. Cumulative drug release was 65.05% within the time-frame of 8 h; the release pattern of the drug followed zero-order kinetics with the Higuchi release mechanism. The average zone of inhibition was found to be 43.44 ± 1.34 mm. The properties of F3 formulation reflect to improve residence time at the site of application and can enhance sustained drug release. Therefore, it could be concluded that optimized formulation has better retention and enhanced antimicrobial activity for superior efficacy against HS.

Hepatitis B and C among patients with hidradenitis suppurativa: a population-based study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory condition related to multiple systemic diseases and infections.

METHODS

This retrospective cross-sectional study from 1999 to 2015 used the database of Clalit Health Services, the largest managed care organization in Israel, to explore the association between HS and hepatitis B and C. Sociodemographic and clinical information was compared using χ² tests for sex and socioeconomic status and t-tests for age. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to compare the odds of hepatitis B and C in those with and without HS.

RESULTS

In multivariate analysis controlling for sex, age as a continuous variable, Arab ancestry, and history of drug abuse, HS was associated with a 1.87-fold increased odds (95% CI 1.11-3.17, P = 0.019) of hepatitis B (HBV). HS was also associated with HCV in multivariate analysis controlling for sex, age per year, Arab ancestry, alcohol use, and drug use, with a 1.74-fold increased odds (95% CI 1.05-2.89, P = 0.032) of hepatitis C (HCV) among those with HS as compared to controls.

CONCLUSIONS

This study demonstrated an association between HS and both hepatitis B and hepatitis C.

Treatment of hidradenitis suppurativa with tetracycline, doxycycline, or lymecycline: a prospective study

AIM

To evaluate the clinical efficacy of tetracycline, doxycycline, and lymecycline in patients with hidradenitis suppurativa (HS).

METHODS

A prospective study of three different treatment regimens in patients with HS; oral tetracycline 500 mg twice daily, oral doxycycline 100 mg twice daily, and oral lymecycline 300 mg twice daily were administered in patients with HS. Outcomes were change in Hidradenitis Suppurativa Score (HSS), Dermatology Life Quality Life index (DLQI), overall disease-related distress, boil-related pain, number of boils in the preceding month, fraction of patients with no boils in the preceding month, and Physician's Global Assessment (PGA) score at follow-up.

RESULTS

In total, 108 patients, 73 (67.6%) women and 35 (32.4%) men, were included. Mean duration of treatment was 4.3 months. The mean HSS at baseline was 26.10 (SD 20.18) points, improving to 17.97 (SD 17.88) at follow-up, difference is 8.13 (95% CI 5.21-10.93), P < 0.0001. Highest improvement in HSS was observed in the tetracycline group. After multivariate adjustment, higher reduction in HSS was significantly associated with lower BMI, Hurley stage III, higher HSS at baseline, and higher number of boils in the preceding month at baseline.

CONCLUSION

Oral treatment with tetracycline, doxycycline, and lymecycline appears effective and safe in HS patients. Tetracycline provided the greatest clinical improvement measured by HSS.

A Systematic Review of Promising Therapeutic Targets in Hidradenitis Suppurativa: A Critical Evaluation of Mechanistic and Clinical Relevance

This systematic review identifies and critically evaluates the mechanistic and clinical evidence of new promising therapeutic targets in hidradenitis suppurativa (HS). Evidence for these targets is largely based on observational data with limited ex vivo and translational data from clinical trials. A number of placebo-controlled studies have been completed or are underway utilizing IL-1, IL-23, IL-17, complement, and Jak inhibition, although there is concern regarding elevated placebo response rates and the questionable validity of clinical scores in some participant subsets. Knowledge gaps are identified suggesting a direction for future mechanistic studies in HS, including more comprehensive inflammatory endotype profiling of disease.

Socioeconomic impact of high-cost drugs in Brazilian dermatology. Legal and financial aspects, and impact on clinical practice

The technological advancement of the pharmaceutical industry, resulting from the techniques of molecular biology and expansion of the knowledge of immunopathogenesis, has modified the therapeutic arsenal used in dermatology. Scientific research and regulatory standards cause drug costs to rise, thus making their use impossible in most public policies. In order to make high-cost drugs viable in the public health network, the Specialized Pharmaceutical Assistance Component was created. However, despite the frequent incorporation of medications, the constant requirement of drugs through lawsuits leads to exorbitant costs to the state budget. The present work analyzed through a descriptive observational study, the current situation of the Specialized Component and the involvement of medicines used in dermatology, through legal reviews, financial analyses, and medical articles, aiming at future incorporations for the specialty. When assessing the legal demands for dermatological drugs in the state of São Paulo, the specialty still has a low participation and psoriasis is the main disease involved in requiring drugs through the judicial system in the state. New methods of access to raw materials must be created to reduce legal issues. Cost-effectiveness and public planning studies are mandatory for incorporating new dermatological therapies.

Pregnancy and breastfeeding in hidradenitis suppurativa: A review of medication safety

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that disproportionately affects women of childbearing age. Pregnancy influences HS severity for many women, thus diligent continued management throughout pregnancy and postpartum may be required. Herein, we provide an updated review of pregnancy and lactation safety data for HS medications, including topical antiseptic washes, topical and systemic antibiotics, biologic and nonbiologic immunomodulators, immunosuppressants, adjunct medical therapies, and pain medications, to help guide risk-benefit discussions between providers and HS patients.

Cytokine Pathways and Investigational Target Therapies in Hidradenitis Suppurativa

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting areas with a high density of apocrine glands and characterized by subcutaneous nodules that may evolve into fistulas with pus secretion. Methods: The aim of this review is to investigate all current knowledge on cytokine regulation in the pathogenesis of HS. A systematic literature research using the words “cytokine”, “interleukin”, “pathway”, and “hidradenitis suppurativa” was performed in PubMed/Medline and Scopus/Embase databases. A search of the clinicaltrials.gov website for interventional recruiting and completed trials including the term “hidradenitis suppurativa” was also performed up to August 2020. We will discuss the pathogenetic role of various cytokines in HS and potential therapeutic targets for this debilitating disease. Results: The pathophysiology underlying this complex condition has not been clearly defined. An upregulation of various cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, IL-17, IL-23, and other molecules seems to be related to this inflammatory condition. Various cells, such as lymphocytes T Helper 1 and 17 and keratinocytes seem to be involved in the genesis of this condition. Conclusions: Several future studies and clinical trials are necessary in order to have new knowledge about HS and to properly treat this complex condition.

Obesity is Not Associated With Need for Skin Grafting After Hidradenitis Excision

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating disease associated with inflammation, recurrent abscesses, and fistulae of skin containing apocrine sweat glands. We hypothesize that the need for skin grafting after vacuum-assisted closure was decreased with increasing body mass index (BMI).

METHODS

Seventy-one consecutive patients with excisions for HS were retrospectively evaluated for demographic data, number of excisions, the total area of excised skin, need for skin grafting, and BMI. Patients were stratified for BMI and underwent logistic regression to compare all other variables.

RESULTS

Average for BMI was 30.8 ± 7.72, age was 36.89 ±13.52, area excised was 743 cm² ± 774 cm², mean operating room trips were 2.62 ± 1.59, and skin grafting was 0.52 ± 0.55. Patients were 60% male. Forty out of 71 patients were obese. There was no correlation between age, BMI, sex, thenumber of excisions, amount of skin excised, or need for a skin graft. There was a statistically significant relationship between the amount of skin excised and the need for skin grafting (P = .006).

CONCLUSIONS

The amount of skin affected by HS appears to be independent of patient BMI. The need for skin grafting is solely dependent upon the amount of tissue excised.

APPLICABILITY OF RESEARCH TO PRACTICE

This knowledge will help preoperative planning for all patients with HS, regardless of BMI.

The most recent advances in understanding and managing hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent, and debilitating skin disease of the hair follicle unit that typically develops after puberty. HS has a significant negative impact on both the quality of life (QOL) of patients affected by this disease as well as family members and caregivers. However, the pathogenesis of HS is multifactorial and still remains to be fully elucidated, which makes the development of treatments difficult. The last 10 years have seen a surge in HS research, and many new findings have come to light, yet much more remains to be elucidated. Physicians must employ a multidisciplinary approach to maximally address all facets of HS. Clinical characteristics of the disease that differ between females and males as well as across different races and ethnic groups must be considered. Targeted topical, oral, and injectable therapies continue to be developed for HS as a greater understanding of the pathogenesis is reached. However, randomized controlled trials regarding dietary factors that may contribute to HS are needed to meet our patients’ growing concerns and questions about the role of diet in HS pathogenesis. Finally, improved outcome measures are needed to standardize HS severity and grading between physicians and clinical trials, and a more diverse representation of HS populations is needed in clinical trials.

Hidradenitis suppurativa in pediatric patients

Interest in and research on hidradenitis suppurativa (HS) have increased during the past decade, resulting in expanded knowledge about associated comorbidities and treatment efficacy. Knowledge about pediatric-onset HS is still limited, based on case studies, small case series, and extrapolation from adult studies. With increasing prevalence of childhood obesity, decreasing pubertal age, and increasing awareness of HS, physicians may start encountering younger HS patients. This review presents an updated discussion on the epidemiology, pathophysiology, and associated comorbidities in HS, with a focus on pediatric and adolescent patients. It also suggests recommendations for investigation and treatment based on current evidence.

A systematic review and critical appraisal of metagenomic and culture studies in hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin disease with still largely unknown pathogenesis. While infectious organisms have been identified in lesions of the disease since the 1980s, questions remain over the role that bacteria and microbiome play. Recent studies using 16S ribosomal RNA gene sequencing and larger culture-based studies have begun to paint a clearer picture of the microbial world of HS. With this systematic review, we summarize all the work that has been done to date in HS bacteriology, analyse potential pitfalls and limitations of the current studies, and address future directions of investigation. This systematic review attempted to collate and analyse all bacteriology studies done to date. This review was prospectively registered with PROSPERO (1670769) performed in line with the PRISMA checklist. Twenty two studies were identified comprising 862 individual HS patients for culture studies and 206 HS patients for 16S rRNA gene sequencing studies. Methodology tended to be varied, with different sampling, culturing and sequencing methods as well as amount of analysis and stratification of patients. Bacteria identified as elevated in HS lesions in sequencing studies as well as grown from HS lesions in culture studies are identified and discussed. These primarily included the anerobic Gram-negative bacilli Prevotella, Porphyromonas and Fusibacterium, the Gram-positive bacilli Corynebacterium, and the Gram-positive cocci Staphylococcus, Streptococcus and Parvimonas. Potential interactions, as well as work in other disease models with related bacteria are also discussed. Areas of further investigation include in vitro studies of interactions between bacteria and keratinocytes, gut and oral microbiome studies and deep sequencing studies for virulence and phage factors.

Biologic therapies for the treatment of hidradenitis suppurativa

Introduction: Hidradenitis suppurativa (HS) is a chronic skin disorder characterized by inflammatory nodules, abscesses, and fistulae. Patients tend to present in young adulthood and are predominantly female. The pathogenesis of HS involves apopilosebaceous gland follicle occlusion and affected areas often occur where this type of gland predominates. Treatment selection depends on HS severity, which is included in different scoring systems. In recent years, biological therapies have been evaluated and used with increasing frequency in moderate-to-severe HS disease.Areas covered: This review focuses on biological therapies for HS as assessed in case reports, case series, and clinical trials. The efficacy, hidradenitis suppurativa scoring systems, and long-term results of these therapies are discussed depending on the studies' endpoints.Expert opinion: Adalimumab is currently the only FDA-approved HS biological therapy. Some patients do not experience treatment efficacy with adalimumab at 40 mg/week, which may result in increasing the dose or seeking other treatments. Infliximab is the next line of HS treatment with demonstrated efficacy. Other biological therapies being studied have demonstrated efficacy in small patient groups, but lack study power. Further studies may provide answers to seeking treatment options for patients who fail to improve on current standard HS treatment.

Case report: Treating a co-existence of hidradenitis suppurativa and psoriasis with different therapeutic approaches

Hidradenitis suppurativa and psoriasis are considered chronic inflammatory diseases suggesting the existence of common pathogenetic pathways. We present two cases of comorbid psoriasis and hidradenitis suppurativa, treated with certolizumab pegol and brodalumab due to failure of response to other conventional therapies. Monoclonal antibody therapies have revolutionized the treatment of chronic inflammatory disorders such as psoriasis and hidradenitis suppurativa. Given the good clinical response to anti-IL-17 and anti-tumor necrosis factor agents in patients undergoing psoriasis and hidradenitis treatment, investigations on this direction could represent the starting point in new therapeutic approach for revolutionary treatment in these difficult-to-treat diseases.