A case of Atopic dermatitis and Hidradenitis Suppurativa successfully treated with Dupilumab

Eosinophils in hidradenitis suppurativa patients exhibit pro-inflammatory traits, implicating a potential pathogenic role in the disease

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful nodules, abscesses and purulent secretions in intertriginous regions. Intense pruritus frequently accompanies HS lesions, adding further discomfort for patients. While Th17 pathway activation is implicated in HS pathogenesis, disease mechanisms are still not fully understood, and therapeutics are lacking. Previous reports raise a potential role for eosinophils in HS, showing a strong association of eosinophil levels with disease severity. To investigate eosinophils in HS, we recruited patients and matched healthy controls and then performed flow-cytometry studies, eosinophil stimulation assays, and lesional skin staining for eosinophils. We found that HS patients reported similar levels of pain and itch. Compared to matched controls, HS blood exhibited decreased mature eosinophils and increased numbers of immature eosinophils, coupled with a significant increase in dermal eosinophilic infiltrates. Additionally, IL-17RA+ eosinophils were highly and significantly correlated with multiple HS-related clinical scores. In both stimulated and unstimulated conditions, HS eosinophils showed an inflammatory phenotype versus controls, including an increase in costimulatory T- and B-cell markers (e.g. CD5 and CD40) following all stimulations (TNFα/IL-17A/IL-17F). These findings highlight the significance of pruritus in HS and suggest a higher turnover of eosinophils in HS blood, potentially due to the consumption of eosinophils in skin lesions. Our data delineate the features and functions of eosinophils in HS and suggest that eosinophils participate in disease pathogenesis, advancing Th17-related inflammation. Further studies are needed to investigate eosinophils' response to current HS treatments and their potential as a therapeutic target in the disease.

Biologics for Hidradenitis suppurativa: evolution of the treatment paradigm

INTRODUCTION

Hidradenitis suppurativa (HS) is an autoinflammatory skin disease with a high unmet need for effective medical management. Clinically, it is characterized by inflammatory nodules that may progress into abscesses, draining tunnels and extensive scarring, mainly affecting apocrine gland-bearing areas.

AREAS COVERED

Treatment options include topical and systemic medications and a variety of surgical procedures. The anti-TNF-α antibody adalimumab and the anti-IL-17 secukinumab are the only two approved biologics for HS, showing moderate efficacy. HS research is a rapidly growing field, with a wide range of agents leveraging distinct mechanisms of action currently under development. Drugs targeting the IL-17 and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are the most advanced in both ongoing and completed Phase 3 studies, promising deeper levels of response. Use of other, off-label biologics is also discussed.

EXPERT OPINION

A therapeutic algorithm is proposed based on comorbidities and existing evidence. Patient-tailored combinations between biologics and other biologics or small molecules will hopefully allow clinicians to target most events in HS pathophysiology in a complementary way while obtaining a meaningful effect on their devastating manifestations.

Transcriptomic Analysis of Hidradenitis Suppurativa: A Unique Molecular Signature with Broad Immune Activation

Hidradenitis suppurativa is a chronic inflammatory skin disease with limited treatment options. The poorly understood pathogenesis hinders the development of effective treatments; therefore, a pressing need exists to further elucidate the molecular mechanisms in hidradenitis suppurativa. This study investigated the underlying inflammatory pathways and cell types in hidradenitis suppurativa using transcriptomic approaches with RNA sequencing of lesional and non-lesional skin biopsies from hidradenitis suppurativa, which was jointly analyzed with previously published transcriptomic data from atopic dermatitis and psoriasis patients. The differential expression and pathway enrichment analyses demonstrated the activation of multiple inflammatory processes, including the innate and adaptive immune systems, implicated in the hidradenitis suppurativa pathogenesis. In agreement, hidradenitis suppurativa exhibited a unique and heterogeneous cell type signature involving lymphoid and myeloid cells such as B cells and macrophages. Furthermore, hidradenitis suppurativa displayed increased expression of TH1/2/17 signatures with no predominant TH signatures unlike psoriasis (TH1/17) and atopic dermatitis (TH2). In summary, our study provides molecular insights into the pathomechanisms in hidradenitis suppurativa, revealing a strong and widespread immune activation, which may benefit from treatment strategies offering a broad immunomodulation of various key inflammatory pathways. Our data not only corroborate previously reported findings but also enhance our understanding of the immune dysregulation in hidradenitis suppurativa, uncovering novel and potential therapeutic targets.

Is Exploration of Alternate Immune Pathways Needed in Hidradenitis Suppurativa? A Case of Atopic Dermatitis and Concurrent Hidradenitis Suppurativa Responding to Dupilumab

Hidradenitis suppurativa (HS) is an inflammatory dermatosis associated with overactive T helper 1/T helper 17 (Th1/Th17) cells. HS has been effectively treated with biologic medications; however, many such biologics lack large randomized controlled trials. Only one such biologic, adalimumab, has been approved by the US Food and Drug Administration (FDA) for the treatment of HS. Other such biologics currently being studied for HS downregulate Th1/Th17 inflammatory pathways. We describe a patient with atopic dermatitis (AD) and comorbid HS, both of which improved several months into treatment with dupilumab. Interestingly enough, dupilumab targets Th2-mediated inflammatory skin conditions through the inhibition of IL-4/IL-13 cytokines. While dupilumab is known for its success in treating Th2-mediated inflammation, this presents a paradox as HS is a Th1/Th17 inflammatory condition. This case highlights how the inflammatory process of HS is not fully understood and how biologic pharmacologic interventions need to be further studied to determine their efficacy in treating HS.

Emerging Treatments and the Clinical Trial Landscape for Hidradenitis Suppurativa Part I: Topical and Systemic Medical Therapies

Hidradenitis suppurativa (HS) is an oftentimes debilitating condition that presents with painful nodules, abscesses, and sinus tracts. This condition is challenging to treat, in part because the pathogenesis of the condition is incompletely understood but also because there are limited therapeutic options. HS research is undergoing explosive growth with multiple new molecular pathways under study, which will hopefully lead to improved disease control for patients. Part I of this review will provide an overview of the emerging topical and systemic therapies under investigation for HS.

Dupilumab in Inflammatory Skin Diseases: A Systematic Review

Dupilumab was first approved for the treatment of atopic dermatitis (AD) and blocks the signaling of interleukin (IL)-4 and -13. Several other chronic skin conditions share mechanistic overlaps with AD in their pathophysiology, i.e., are linked to type 2 inflammation. Most recently, dupilumab was approved by the U.S. Food and Drug Administration for prurigo nodularis (PN). Given its relatively good safety profile, effective off-label use of dupilumab has been reported for a multitude of dermatologic diseases and several clinical trials for dermatologic skin conditions are currently ongoing. We conducted a systematic review of applications of dupilumab in dermatology other than AD and PN by searching the databases PubMed/Medline, Scopus, Web of Science and Cochrane Library as well as the clinical trial registry ClinicalTrials.gov. We found several reports for effective treatment of bullous autoimmune diseases, eczema, prurigo, alopecia areata, chronic spontaneous urticaria, Netherton syndrome and a variety of other chronic inflammatory skin diseases.

Novel and Off-Label Biologic Use in the Management of Hidradenitis Suppurativa, Pyoderma Gangrenosum, Lichen Planus, and Seborrheic Dermatitis: A Narrative Review

With advances in drug development and our understanding of the pathophysiology of skin disease, biologic medications have emerged as powerful management tools for dermatologists. While biologics have most often been used in the management of psoriasis, they are being used off-label for the management of a variety of other immune-mediated skin diseases with overlapping molecular targets. This narrative review focuses on the novel and off-label use of biologic medications for the management of hidradenitis suppurativa (HS), pyoderma gangrenosum (PG), lichen planus (LP), and seborrheic dermatitis (SD). Review of the literature revealed that IL-17, IL-23, and tumor necrosis factor (TNF) inhibitors were being used across a variety of immune-mediated skin pathologies with variable efficacy, among other targeted biologics. While biologics were generally safe in the treatment of primary immune-mediated skin disorders, paradoxical disease eruptions were noted with biologic use and were theorized to occur owing to immune dysregulation and cytokine imbalance. While numerous case reports show promise for the use of biologics in immune-mediated skin pathologies, the variable efficacy and safety reported warrants more thorough investigations of the role of these targeted medications in comprehensive disease management.

Hidradenitis suppurativa and atopic dermatitis: A 2-way association

BACKGROUND

The coexistence of hidradenitis suppurativa (HS) and atopic dermatitis (AD) had been reported but, to our knowledge, was not investigated in controlled studies.

OBJECTIVE

To evaluate the bidirectional association between HS and AD.

METHODS

A population-based retrospective cohort study was conducted to compare the incidence rate of AD among patients with HS (n = 6779) and age-, sex-, and ethnicity-matched control individuals (n = 33,260). Adjusted hazard ratios (HRs) and adjusted odds ratios were estimated.

RESULTS

The incidence of AD was 2.51 (95% confidence interval [CI], 2.07-3.02) and 1.24 (95% CI, 1.10-1.40) per 1000 person-years among patients with HS and control individuals, respectively. Patients with HS were twice as likely to develop AD as control individuals (HR, 2.06; 95% CI, 1.64-2.58). Furthermore, the prevalence of pre-existing AD was higher in patients with HS than in control individuals (2.5% vs 1.8%, respectively; P < .001). A history of AD was associated with a 40% increase in the odds of HS (odds ratio, 1.41; 95% CI, 1.19-1.67). Relative to patients with isolated HS, those with a dual diagnosis of HS and AD were younger and had a female predominance, lower prevalence of smoking, and lower body mass index.

LIMITATIONS

Retrospective data collection.

CONCLUSIONS

A bidirectional association between HS and AD was observed. Dermatologists should be aware of this association.

Dupilumab use in atopic dermatitis and beyond in skin diseases

Atopic dermatitis (AD) is a chronic inflammatory condition that affects 5-10% of adults and 9-18% of children and its pathology is rooted in the Th-2-mediated immune response. Dupilumab is a fully human IgG4 monoclonal antibody that targets the IL-4 receptor alpha subunit that is endogenously bound by the Th-2 cytokines IL-4 and IL-13. Successful clinical trials of dupilumab showing marked improvements in clinical signs of AD, patient reported symptoms and quality of life measures led to its approval for clinical use for moderate-to-severe AD in 2017. This review details the current body of evidence on the drug's mechanism of action, pharmacology, clinical efficacy and safety as well as post market and real world use.

Immunomodulatory drugs alone and adjuvant to surgery for hidradenitis suppurativa/acne inversa-A narrative review

Hidradenitis suppurativa/acne inversa (HS/AI) is one of the most debilitating dermatoses with a strong negative impact on every dimension of quality of life. Treatment is dependent on the severity of clinical manifestations and comorbidities. While anti-inflammatory and antimicrobial approaches are recommended for mild and moderate stages, immunomodulatory drugs have gained increasing interest in all stages of HS/AI. We reviewed the available data on this subject in a narrative review and included not only substances with published final outcome but those where either the ongoing trials or experience from case report. Furthermore, we investigated combined surgical therapy and immunomodulatory drugs and raised specific questions to be answered in controlled settings. This aspect seems to be underrepresented. The first approved medical treatment for HS/AI is adalimumab. Other cytokine, interleukin, Janus kinase and C5a inhibitors and antagonists are under investigation. IL-1 inhibitors and antagonists may become an option for mild to moderate HS/AI, while most of the other medical compounds target moderate to severe HS/AI. Despite medical efforts with immunomodulatory agents, surgery remains a cornerstone of efficient HS/AI therapy. Better outcome in advanced disease might be achieved by combining drug therapy and surgery, but more systematic clinical trials are necessary for the optimal combination.