Prevalence and Risk of Inflammatory Bowel Disease in Patients with Hidradenitis Suppurativa

The gut-skin axis: a bi-directional, microbiota-driven relationship with therapeutic potential

This review explores the emerging term "gut-skin axis" (GSA), describing the bidirectional signaling that occurs between the skin and the gastrointestinal tract under both homeostatic and disease conditions. Central to GSA communication are the gut and skin microbiota, the microbial communities that colonize these barrier surfaces. By influencing diverse host pathways, including innate immune, vitamin D receptor, and Aryl hydrocarbon receptor signaling, a balanced microbiota contributes to both tissue homeostasis and host defense. In contrast, microbiota imbalance, or dysbiosis at one site, can lead to local barrier dysfunction, resulting in the activation of signaling pathways that can disrupt tissue homeostasis at the other site, potentially leading to inflammatory skin conditions such as atopic dermatitis and psoriasis, or gut diseases like Inflammatory Bowel Disease. To date, most research on the GSA has examined the impact of the gut microbiota and diet on skin health, but recent studies show that exposing the skin to ultraviolet B-light can beneficially modulate both the gut microbiome and intestinal health. Thus, despite the traditional focus of clinicians and researchers on these organ systems as distinct, the GSA offers new opportunities to better understand the pathogenesis of cutaneous and gastrointestinal diseases and promote health at both sites.

Inflammatory Bowel Disease Prevalence in Patients with Hidradenitis Suppurativa Using Prospective Symptom-Based Questionnaires and Fecal Calprotectin Testing

INTRODUCTION

Hidradenitis suppurativa (HS) is associated with inflammatory bowel disease (IBD). Using healthcare databases, an estimated 2.1% of patients with HS have IBD. Prospective screening of patients with HS with IBD sign/symptom-based questions and fecal calprotectin (FC) has not been studied. Our aim was to evaluate the prevalence of IBD in HS and the utility of a sign/symptom-based questionnaire and FC testing.

METHODS

All patients with HS attending two clinics were invited to participate. Information was collected on demographics, HS severity, and IBD risk factors. Fecal samples were returned by patients for calprotectin testing (≤ 50 μg/g = negative, 50-150 μg/g = borderline, ≥ 150 μg/g = positive).

RESULTS

We recruited 150 patients including 124 women (82.7%) with a median age of 36 years and Hurley stage 2/3 disease (88.6%); 11 patients had established IBD (7.3%). Up to 44.7% of patients reported gastrointestinal symptoms. In 98 patients who returned a fecal sample for calprotectin measurement, 10 had previously diagnosed IBD (10.3%), 81 had a negative FC (82.7%), 13 had a borderline FC (13.3%) and 4 had a positive FC (4.1%). Among 4 patients with a positive result, 2 had known IBD (50%); 2 without established IBD were referred to gastroenterology and 1 had a negative endoscopy reporting an acute diarrheal illness at the time of their FC. The second patient was diagnosed with endoscopic and histologic Crohn's disease.

CONCLUSIONS

We report an IBD prevalence of 8%, higher than previous studies. Routine IBD sign/symptom-based assessment is currently recommended. In our study, this would result in a referral rate of 44.7%. Among 88 FC tests in patients without established IBD, 1 patient was diagnosed with incident occult Crohn's disease. At a number needed to screen (NNS) of 88, routine evaluation of all patients with HS with FC may be justified especially prior to the use of interleukin (IL)-17 antagonists.

Hidradenitis Suppurativa and Ocular Diseases: Real-world Evidence of 57,972 Patients

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurring dermal abscesses and cutaneous fistulas of intertriginous skin regions, significantly impacting patients' quality of life. While HS has been associated with various comorbidities such as metabolic and chronic inflammatory diseases, many systemic effects of this systemic disease remain to be investigated. In this study, 2 cohorts of patients with and without HS were created - matched for sex, age, and nicotine dependence - each comprising 28,986 patients, using the real-world database TriNetX, to investigate the association of ocular diseases and HS. Not only an increased risk of disorders of refraction and accommodation in HS patients (OR 3.466; 95% CI 3.100, 3.876), but also a higher risk of ocular diseases, including disorders of the lacrimal system, was demonstrated when compared with the control cohort (OR 3.523; 95%CI 2.912, 4.263). Although previous studies have suggested an increased risk of ocular comorbidities in HS patients, ocular history is not routinely queried during visits. Here, the need for further exploration of the association of ocular diseases and HS and for incorporating this into clinical practice is emphasized.

Comorbidities and Quality of Life in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a debilitating, chronic inflammatory disease that results in painful nodules, abscess, and draining tunnels which eventuate in morbid scarring. Patients with HS are at risk for various cutaneous and systemic comorbid diseases including inflammatory bowel disease, cardiovascular, endocrine, and psychiatric conditions. Given its high symptom burden, chronic and progressive course, and association with comorbid conditions, HS has a profound life impact on patients.

Beyond the skin: endocrine, psychological and nutritional aspects in women with hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin disorder that primarily affects body folds and the genital area, with a higher prevalence in women across Europe. The pathogenesis of HS involves a complex interplay of intrinsic and extrinsic factors, including genetics, immunity, hormones, and environmental influences. HS is frequently associated with a variety of comorbidities, such as metabolic, endocrine, and gastrointestinal conditions, as well as mental health disorders. Although the symptoms of HS are generally similar in both men and women, female patients may experience exacerbations of HS due to hormonal fluctuations during menstruation, pregnancy, breastfeeding, and menopause. These hormonal changes require special consideration by clinicians when managing HS in women. Due to its chronic nature and frequent flare-ups, HS significantly impacts patients' quality of life, affecting social interactions, emotional well-being, and psychological health. Women with HS may also experience sexual dysfunction, which is further exacerbated by emotional burdens such as shame, loss of femininity, and diminished intimacy. This review highlights key aspects of HS, extending beyond its skin manifestations to address endocrine, psychological, and nutritional aspects in the female population. It also underscores the importance of multidisciplinary collaboration in providing comprehensive care for women with this debilitating condition. Given the limited and largely off-label treatment options, a holistic approach is essential to ensure an appropriate management.

Hidradenitis suppurativa

Hidradenitis suppurativa is a chronic inflammatory disease characterised by painful, deep-seated nodules, abscesses, and draining tunnels in the skin of axillary, inguinal, genitoanal, or inframammary areas. In recent years, the body of knowledge in hidradenitis suppurativa has advanced greatly. This disorder typically starts in the second or third decade of life. The average worldwide prevalence is 1% but varies geographically. Hidradenitis suppurativa has a profound negative effect on patients' quality of life and on the gross value added to society. Comorbidities (eg, metabolic syndrome, inflammatory arthritis, and inflammatory bowel disease) frequently accompany skin alterations, because of systemic inflammation. Pathogenesis of hidradenitis suppurativa is complex and includes innate immune mechanisms (eg, macrophages, neutrophils, IL-1β, tumour necrosis factor [TNF], and granulocyte colony-stimulating factor), T-cell mechanisms (eg, IL-17 and IFN-γ), and B-cell mechanisms (eg, associated with dermal tertiary lymphatic structures and autoantibodies). Chronic inflammation leads to irreversible skin damage with tunnel formation and morbid scarring. Current treatment includes drug therapy (for the initial, purely inflammatory phase), combined drug and surgical therapy (for the destructive phase), or surgery alone (for the burnout phase). The first systemic therapies approved for hidradenitis suppurativa targeting TNF (adalimumab) and IL-17 (secukinumab and bimekizumab) have expanded drug therapy options for moderate-to-severe disease, which were previously mainly restricted to oral antibiotics. Moreover, there is a robust pipeline of immunomodulatory drugs in various stages of development for hidradenitis suppurativa. Aims of management should include early intervention to prevent irreversible skin damage, adequate control of symptoms including pain, and mitigation of extra-cutaneous comorbidities, all requiring early diagnosis and an interdisciplinary, holistic and personalised approach.

Epidemiology of hidradenitis suppurativa and its comorbid conditions

Hidradenitis suppurativa (HS) is a chronic, inflammatory condition predominantly affecting younger adults and disproportionately affecting women and Black Americans. Estimated prevalences vary significantly according to study methodology; however, true prevalence may range from approximately 0.1% to 1%. Hidradenitis suppurativa is associated with a number of comorbid conditions which also contribute to poor health outcomes and negative impact on quality of life. Recent advancements in our understanding of disease burden in hidradenitis suppurativa have allowed us to identify subgroups of the population afflicted with the disease and to implement strategies which facilitate comprehensive care.

Bimekizumab for the treatment of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a painful, inflammatory dermatosis involving recurrent abscesses, nodules and tunnels in intertriginous regions. Biologics and other immunomodulators have significantly expanded the treatment options available for HS. Bimekizumab is a monoclonal antibody targeting both interleukin-17A and interleukin-17F, key mediators of inflammation, that is already approved for psoriasis, psoriatic arthritis and axial spondylarthritis. It is currently pending FDA review for HS treatment but has already received marketing authorization for this indication in Europe. This review aims to explore drug-specific characteristics of bimekizumab including its mechanism of action, pharmacokinetics and pharmacodynamics and the current state of the literature regarding its use in HS such as safety, efficacy and dosing, while highlighting its implications in clinical practice. Recent Phase II and III trial data demonstrating positive efficacy and safety profiles in the treatment of HS will also be detailed.

Hidradenitis Suppurativa-Related Autoinflammatory Syndromes: An Updated Review on the Clinics, Genetics, and Treatment of Pyoderma gangrenosum, Acne and Suppurative Hidradenitis (PASH), Pyogenic Arthritis, Pyoderma gangrenosum, Acne and Suppurative Hidradenitis (PAPASH), Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO), and Rarer Forms

Hidradenitis suppurativa (HS) is an autoinflammatory skin disorder of the terminal hair follicle, which can present in sporadic, familial, or syndromic form. A classification has been proposed for the latter, distinguishing cases associated with a known genetic condition, with follicular keratinization disorders or with autoinflammatory diseases. This review focuses on the clinical and genetic features of those entities (ie, pyoderma gangrenosum [PG], acne and HS; PG, acne, pyogenic arthritis and HS; psoriatic arthritis, PG, acne and HS; synovitis, acne, pustulosis, hyperostosis, osteitis; and so forth) for which the collective term HS-related autoinflammatory syndromes is proposed.

What should a surgeon know about hidradenitis suppurativa?

Otherwise known as Verneuil's disease, hidradenitis suppurative (HS) is a severe dermatosis of heterogeneous appearance affecting 1% of the population. Its pathophysiology is multifactorial, involving genetic predisposition, inflammatory disorder and environmental elements. Its diagnosis is based on the association of three clinical characteristics: characteristic lesions, typical localizations, and the chronic and recurrent nature of the lesions. Given its diversified aspects, diagnosis can be difficult to achieve. As its manifestations often include abscesses, it is important for the surgeon to know how to detect this pathology. The development of biologics has improved treatment of this disease, treatment that necessitates a multidisciplinary medical and surgical approach involving dermatologists and proctologists as well as surgeons. The objective of this report is to synthesize what a surgeon will need to know so as effectively treat HS patients.

Comparative diet-gut microbiome analysis in Crohn's disease and Hidradenitis suppurativa

Introduction

The chronic inflammatory skin disease Hidradenitis suppurativa (HS) is strongly associated with Crohn's Disease (CD). HS and CD share clinical similarities and similar inflammatory pathways are upregulated in both conditions. Increased prevalence of inflammatory disease in industrialised nations has been linked to the Western diet. However, gut microbiota composition and diet interaction have not been compared in HS and CD.

Methods

Here we compared the fecal microbiota (16S rRNA gene amplicon sequencing) and habitual diet of previously reported subjects with HS (n = 55), patients with CD (n = 102) and controls (n = 95).

Results and discussion

Patients with HS consumed a Western diet similar to patients with CD. Meanwhile, habitual diet in HS and CD was significantly different to controls. Previously, we detected differences in microbiota composition among patients with HS from that of controls. We now show that 40% of patients with HS had a microbiota configuration similar to that of CD, characterised by the enrichment of pathogenic genera (Enterococcus, Veillonella and Escherichia_Shigella) and the depletion of putatively beneficial genera (Faecalibacterium). The remaining 60% of patients with HS harboured a normal microbiota similar to that of controls. Antibiotics, which are commonly used to treat HS, were identified as a co-varying with differences in microbiota composition. We examined the levels of several inflammatory markers highlighting that growth-arrest specific 6 (Gas6), which has anti-inflammatory potential, were significantly lower in the 40% of patients with HS who had a CD microbiota configuration. Levels of the pro-inflammatory cytokine IL-12, which is a modulator of intestinal inflammation in CD, were negatively correlated with the abundance of health-associated genera in patients with HS. In conclusion, the fecal microbiota may help identify patients with HS who are at greater risk for development of CD.

Epidemiology of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent skin disease affecting hair follicles in predominantly intertriginous areas, characterized by deep, painful nodules and abscesses, fistulas, sinus tracts, and scarring. The estimated global prevalence of HS is highly variable, as revealed in a growing body of published literature, and ranges from 0.053% to 4.1%. In North American and European patients, HS is three times more common in women than men, whereas in South Korea and Japan, male predominance is found. The disease most frequently manifests itself between the ages of 18 and 29. Numerous published studies have reported the association between smoking, obesity, and HS, although there are limitations in confirming the causal relationship due to the retrospective design of the available studies. Case-control studies have frequently evaluated the association between HS, metabolic syndrome, and other systemic comorbidities. Due to increased mental health problems, a higher risk of suicide in patients with HS has been reported. We provide up-to-date evidence about the epidemiology, genetic and environmental risk factors, comorbidities, and quality of life of patients with HS. The divergence in HS frequency, possibly due to differences in populations and methodologies, remains to be explained in future worldwide studies.

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.

Neutrophilic granulocyte-derived B-cell activating factor supports B cells in skin lesions in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by painful inflamed nodules, abscesses, and pus-draining tunnels appearing in axillary, inguinal, and perianal skin areas. HS lesions contain various types of immigrated immune cells.

OBJECTIVE

This study aimed to characterize mediators that support lesional B/plasma cell persistence in HS.

METHODS

Skin samples from several cohorts of HS patients and control cohorts were assessed by mRNA sequencing, quantitative PCR on reverse-transcribed RNA, flow cytometry, and immunohistofluorescence. Blood plasma and cultured skin biopsy samples, keratinocytes, dermal fibroblasts, neutrophilic granulocytes (neutrophils), monocytes, and B cells were analyzed. Complex systems biology approaches were used to evaluate bulk and single-cell RNA sequencing data.

RESULTS

Proportions of B/plasma cells, neutrophils, CD8+ T cells, and M0 and M1 macrophages were elevated in HS lesions compared to skin of healthy and perilesional intertriginous areas. There was an association between B/plasma cells, neutrophils, and B-cell activating factor (BAFF, aka TNFSF13B). BAFF was abundant in HS lesions, particularly in nodules and abscesses. Among the cell types present in HS lesions, myeloid cells were the main BAFF producers. Mechanistically, granulocyte colony-stimulating factor in the presence of bacterial products was the major stimulus for neutrophils' BAFF secretion. Lesional upregulation of BAFF receptors was attributed to B cells (TNFRSF13C/BAFFR and TNFRSF13B/TACI) and plasma cells (TNFRSF17/BCMA). Characterization of the lesional BAFF pathway revealed molecules involved in migration/adhesion (eg, CXCR4, CD37, CD53, SELL), proliferation/survival (eg, BST2), activation (eg, KLF2, PRKCB), and reactive oxygen species production (eg, NCF1, CYBC1) of B/plasma cells.

CONCLUSION

Neutrophil-derived BAFF supports B/plasma cell persistence and function in HS lesions.

The Development of Systemic Inflammatory Diseases in Hidradenitis Suppurativa

It is understood that the skin is a peripheral lymphoid tissue that defends against external environmental stimuli. Continuous activation from these factors, on the other hand, promotes persistent inflammation at the local location and, occasionally, tissue damage. Hidradenitis suppurativa (HS) is a typical inflammatory skin disease and becomes a source of numerous inflammatory cytokines due to the chronic intractable repeated inflamed tissues. Because inflammatory cells and cytokines circulate throughout the body from the inflamed organ, it has been hypothesized that HS-mediated skin inflammation impacts the systemic functioning of numerous organs. Recent updates to clinical and experimental investigations revealed that HS has a significant connection with systemic inflammatory disorders. We provide the details and comprehensive molecular mechanisms associated with systemic inflammatory illnesses due to HS.

A Practical Guide for Primary Care Providers on Timely Diagnosis and Comprehensive Care Strategies for Hidradenitis Suppurativa

Hidradenitis suppurativa is a chronic, progressive inflammatory disease of the skin with many systemic implications. Hidradenitis suppurativa is frequently underdiagnosed or misdiagnosed, particularly because of heterogeneity in presentation and low disease recognition. Patients can see multiple types of health care providers, including primary care providers, along their journey to an accurate diagnosis. This review provides a comprehensive overview of the clinical presentation, associated comorbidities, and life impact associated with hidradenitis suppurativa. Disease features described here can facilitate earlier identification of hidradenitis suppurativa, differentiation from common mimickers, and timely referrals for multidisciplinary management when needed. Engagement of the medical community will also support comprehensive care strategies necessary in hidradenitis suppurativa.

Large-scale serum analysis identifies unique systemic biomarkers in psoriasis and hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is now recognized as a systemic inflammatory disease, sharing molecular similarities with psoriasis. Direct comparison of the systemic inflammation in HS with psoriasis is lacking.

OBJECTIVES

To evaluate the serum proteome of HS and psoriasis, and to identify biomarkers associated with disease severity.

METHODS

In this cross-sectional study, 1536 serum proteins were assessed using the Olink Explore (Proximity Extension Assay) high-throughput panel in patients with moderate-to-severe HS (n = 11), patients with psoriasis (n = 10) and age- and body mass index-matched healthy controls (n = 10).

RESULTS

HS displayed an overall greater dysregulation of circulating proteins, with 434 differentially expressed proteins (absolute fold change ≥ 1·2; P ≤ 0·05) in patients with HS vs. controls, 138 in patients with psoriasis vs. controls and 503 between patients with HS and patients with psoriasis. Interleukin (IL)-17A levels and T helper (Th)1/Th17 pathway enrichment were comparable between diseases, while HS presented greater tumour necrosis factor- and IL-1β-related signalling. The Th17-associated markers peptidase inhibitor 3 (PI3) and lipocalin 2 (LCN2) were able to differentiate psoriasis from HS accurately. Both diseases presented increases of atherosclerosis-related proteins. Robust correlations between clinical severity scores and immune and atherosclerosis-related proteins were observed across both diseases.

CONCLUSIONS

HS and psoriasis share significant Th1/Th17 enrichment and upregulation of atherosclerosis-related proteins. Despite the greater body surface area involved in psoriasis, HS presents a greater serum inflammatory burden.

Insights into hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, debilitating, inflammatory skin disorder with a prevalence of around 1% and a profound impact on patients' quality of life. Characteristic lesions such as inflammatory nodules, abscesses, and sinus tracts develop in the axillae, inguinal, and gluteal areas, typically during or after puberty. A complex interplay of genetic predisposition, hormonal factors, obesity, and smoking contributes to development and maintenance of the disease. HS is considered to arise from an intrinsic defect within the hair follicle, leading to follicular plugging, cyst formation, and subsequent rupture that in turn induce an acute inflammatory response characterized by elevated levels of IL-1β, IL-17, and TNF. Over time, acute lesions transition into chronic disease, with active draining sinus tracts accompanied by extensive fibrosis. HS is associated with other immune-mediated inflammatory diseases, metabolic and cardiovascular disorders, and psychiatric comorbidities. Treatment of HS often requires a combination of antibiotic or immunosuppressing therapies and surgical intervention. Nonetheless, the currently available treatments are not universally effective, and many drugs, which are often repurposed from other inflammatory diseases, are under investigation. Studies into the early stages of HS may yield treatments to prevent disease progression; yet, they are hampered by a lack of appropriate in vitro and animal models.

Characterization of comorbidity heterogeneity among 13,667 patients with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disorder characterized by recurrent abscesses in the groin and flexural areas. HS is associated with a wide range of comorbidities that complicate the disease course. Although these comorbidities have been well described, it remains unclear how these comorbidities coassociate and whether comorbidity profiles affect disease trajectory. In addition, it is unknown how comorbidity associations are modulated by race and sex. In this comprehensive analysis of 77 million patients in a large US population–based cohort, we examined coassociation patterns among HS comorbidities and identified clinically relevant phenotypic subtypes within HS. We demonstrated that these subtypes not only differed among races, but also influenced clinical outcomes as measured by HS-related emergency department visits and cellulitis. Taken together, our findings provide key insights that elucidate the unique disease trajectories experienced by patients with HS and equip clinicians with a framework for risk stratification and improved targeted care in HS.

Successful treatment of hidradenitis suppurativa with secukinumab in a patient with ankylosing spondylitis and Familial Mediterranean Fever

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterised by pain, inflamed nodules, abscess, sinus tract, and fistula. HS is more common in patients with axial spondyloarthritis and Familial Mediterranean Fever (FMF) compared to the normal population. Mediterranean fever gene mutations are thought to be responsible for the relationship between these three diseases. Case reports of secukinumab treatment in HS have been reported. In this article, a case of successful treatment of HS with secukinumab in a patient with ankylosing spondylitis and FMF is presented.

Efficacy and Safety of Bimekizumab in Moderate to Severe Hidradenitis Suppurativa: A Phase 2, Double-blind, Placebo-Controlled Randomized Clinical Trial

Question

What is the efficacy and safety of bimekizumab in individuals with moderate to severe hidradenitis suppurativa (HS)?

Findings

In this double-blind, placebo-controlled, phase 2 randomized clinical trial including 90 randomized patients with HS (73 completed the trial), bimekizumab demonstrated clinically meaningful and consistent improvements in participants with HS vs placebo across all assessed outcome measures. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%) and 2 of 21 placebo-treated participants (10%).

Meaning

These initial clinical efficacy and safety data suggest that dual inhibition of interleukin 17A and 17F by bimekizumab may be a viable treatment approach for HS, with the potential to achieve deep responses in clinical outcome measures, and support further evaluation.

Importance

Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a high burden for patients and limited existing therapeutic options.

Objective

To evaluate the efficacy and safety of bimekizumab, a monoclonal IgG1 antibody that selectively inhibits interleukin 17A and 17F in individuals with moderate to severe HS.

Design, Setting, and Participants

This phase 2, double-blind, placebo-controlled randomized clinical trial with an active reference arm was performed from September 22, 2017, to February 21, 2019. The study included a 2- to 4-week screening period, a 12-week treatment period, and a 20-week safety follow-up. Of 167 participants screened at multiple centers, 90 were enrolled. Eligible participants were 18 to 70 years of age with a diagnosis of moderate to severe HS 12 months or more before baseline.

Interventions

Participants with HS were randomized 2:1:1 to receive bimekizumab (640 mg at week 0, 320 mg every 2 weeks), placebo, or reference arm adalimumab (160 mg at week 0, 80 mg at week 2, and 40 mg every week for weeks 4-10).

Main Outcomes and Measures

The prespecified primary efficacy variable was the proportion of participants with a 50% or greater reduction from baseline in the total abscess and inflammatory nodule count with no increase in abscess or draining fistula count (Hidradenitis Suppurativa Clinical Response [HiSCR] at week 12. Exploratory variables included proportion achieving a modified HiSCR with 75% reduction of HiSCR criteria (HiSCR₇₅) or a modified HiSCR with 90% reduction of HiSCR criteria (HiSCR₉₀), change in Patient’s Global Assessment of Pain, and Dermatology Life Quality Index total scores.

Results

Eighty-eight participants received at least 1 dose of study medication (61 [69%] female; median age, 36 years; range, 18-69 years). Seventy-three participants completed the study, including safety follow-up. Bimekizumab demonstrated a higher HiSCR rate vs placebo at week 12 (57.3% vs 26.1%; posterior probability of superiority equaled 0.998, calculated using bayesian analysis). Bimekizumab demonstrated greater clinical improvements compared with placebo. Improvements in the International Hidradenitis Suppurativa Severity Score (IHS4) were seen at week 12 with bimekizumab (mean [SD] IHS4, 16.0 [18.0]) compared with placebo (mean [SD] IHS4, 40.2 [32.6]). More bimekizumab-treated participants achieved positive results on stringent outcome measures compared with placebo. At week 12, 46% of bimekizumab-treated participants achieved HiSCR₇₅ and 32% achieved HiSCR₉₀, whereas 10% of placebo-treated participants achieved HiSCR₇₅ and none achieved HiSCR₉₀; in adalimumab-treated participants, 35% achieved HiSCR₇₅ and 15% achieved HiSCR₉₀. One participant withdrew because of adverse events. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%), 2 of 21 placebo-treated participants (10%), and 1 of 21 adalimumab-treated participants (5%).

Conclusions and Relevance

In this phase 2 randomized clinical trial, bimekizumab demonstrated clinically meaningful improvements across all outcome measures, including stringent outcomes. Bimekizumab’s safety profile was consistent with studies of other indications, supporting further evaluation in participants with HS.

Trial Registration

ClinicalTrials.gov Identifier: NCT03248531

Risk of inflammatory bowel disease in patients with psoriasis, psoriatic arthritis and ankylosing spondylitis initiating interleukin 17 inhibitors: a nationwide population-based study using the French national health data system

OBJECTIVES

To investigate whether IL17-inhibitors (IL17i) initiation in real life is associated with a higher risk of inflammatory bowel disease (IBD) in patients with psoriasis (PsO), psoriatic arthritis and ankylosing spondylitis (PsA/AS).

METHODS

This nationwide cohort study involved the French national health data system database. All adults with PsO and PsA/AS who were new-users of IL17i during 2016-2019 were included. Two non-exposed PsO and PsA/AS population were included: new-users of (1) apremilast and (2) etanercept. End of follow-up was September 30, 2019. The primary end-point was an occurrence of IBD in a time-to-event analysis with propensity score-weighted Cox and Fine-Gray models.

RESULTS

A total of 16,793 IL17i new-users (mean age 48.4±13 years; 46% men); 20,556 apremilast new-users (mean age 52.5±14.6 years; 53% men); and 10,245 etanercept new-users (mean age 46.3±15 years; 44% men) were included. Previous systemic treatements were closer between IL17i and etanercept compared with apremilast. IBD occurred in 132 cases: 72 (0.43%) in IL17i new-users, 11 (0.05%) in apremilast new-users and 49 (0.48%) in etanercept new-users. Most IBD cases occurred after 6 months of exposure (82%, 55% and 76% respectively). After propensity score weighting, the risk of IBD was significantly greater with IL17i than apremilast (HR_w 3.8, 95%CI 2.1-6.8). No difference was observed between IL17i and etanercept new-users (HR_w 0.8, 95%CI 0.5-1.2).

CONCLUSION

Compared with patients initiating etanercept that displayed the same severity of the underlying disease, IL17i new-users did not present a higher risk of IBD. These results need to be confirmed in other large databases.

Effectiveness of interdisciplinary combined dermatology-gastroenterology-rheumatology clinical care compared to usual care in patients with immune-mediated inflammatory diseases: a parallel group, non-blinded, pragmatic randomised trial

INTRODUCTION

Immune-mediated inflammatory diseases (IMIDs) are associated with reduced health-related quality of life (HRQol), increased risk of somatic and psychiatric comorbidities and reduced socioeconomic status. Individuals with one IMID have an increased risk for developing other IMIDs. The unmet needs in the care of patients with IMIDs may result from a lack of patient-centricity in the usual monodisciplinary siloed approach to these diseases. The advantages of novel interdisciplinary clinics towards the traditional therapeutic approach have not been investigated. The overall aim of this study is to determine the effectiveness of an interdisciplinary combined clinic intervention compared with usual care in a population of patients with the IMIDs: psoriasis, hidradenitis suppurativa, psoriatic arthritis, axial spondyloarthritis and inflammatory bowel disease. Our hypothesis is that an interdisciplinary combined clinic intervention will be more effective than usual care in improving clinical and patient-reported outcomes, and that a more effective screening and management of other IMIDs and comorbidities can be performed.

METHODS AND ANALYSIS

This is a randomised, usual care controlled, parallel-group pragmatic clinical trial. 300 consecutively enrolled participants with co-occurrence of at least two IMIDs are randomly assigned in a 2:1 ratio to either treatment in the interdisciplinary combined clinic or usual care. The study will consist of a 6-month active intervention period and a 6-month follow-up period where no intervention or incentives will be provided by the trial. The primary outcome is the change from baseline to 24 weeks on the Short-Form Health Survey (SF-36) Physical Component Summary. Additional patient-reported outcome measures and clinical measures are assessed as secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval of this study protocol was established by the institutional review board of the study site. The findings from this trial will be disseminated via conference presentations and publications in peer-reviewed journals, and by engagement with patient organisations.

TRIAL REGISTRATION NUMBER

NCT04200690.

The Temporal Relationships and Associations between Cutaneous Manifestations and Inflammatory Bowel Disease: A Nationwide Population-Based Cohort Study

The temporal relationships between inflammatory bowel disease (IBD)-associated cutaneous manifestations and IBD remain uncertain, with existing evidence mostly from separate cross-sectional studies. We sought to determine the risks of IBD-related dermatologic diseases before and after the diagnosis of IBD. We identified 2847 cases of IBD and 14,235 matched controls from the Taiwan National Health Insurance Research Database between 2003 and 2014. The risks of cutaneous manifestations before and after the diagnosis of IBD were estimated with multivariable-adjusted analyses. At diagnosis, IBD was associated with atopic dermatitis (odds ratio (OR) = 1.61; 95% confidence interval (CI), 1.14-2.28), erythema nodosum (OR = 7.44; 95%CI, 3.75-14.77), aphthous stomatitis (OR = 2.01; 95%CI, 1.72-2.35), polyarteritis nodosa (OR = 5.67; 95%CI, 2.69-11.98), rosacea (OR = 1.67, 95%CI = 1.19-2.35), and cutaneous T cell lymphoma (OR = 21.27; 95%CI, 2.37-191.00). IBD was associated with the subsequent development of pyoderma gangrenosum (hazard ratio (HR) = 17.79; 95%CI, 6.35-49.86), erythema nodosum (HR = 6.54; 95%CI, 2.83-15.13), polyarteritis nodosa (HR = 2.69; 95%CI, 1.05-6.90), hidradenitis suppurativa (HR = 2.48; 95%CI, 1.03-5.97), psoriasis (HR = 2.19; 95%CI, 1.27-3.79), rosacea (HR = 1.92; 95%CI, 1.39-2.65), and aphthous stomatitis (HR = 1.45; 95%CI, 1.22-1.72). This study clarified the associations and temporal relationships between cutaneous manifestations and IBD, highlighting the need for interdisciplinary care in the patient with specific dermatologic diseases presenting with abdominal symptoms, or the IBD patients with cutaneous lesions.

Identifying key components and therapeutic targets of the immune system in hidradenitis suppurativa with an emphasis on neutrophils

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent and debilitating skin disease of the hair follicle unit that typically develops after puberty. The disorder is characterized by comedones, painful inflammatory nodules, abscesses, dermal tunnels and scarring, with a predilection for intertriginous areas of the body (axillae, inguinal and anogenital regions). Recruitment of neutrophils to HS lesion sites may play an essential role in the development of the painful inflammatory nodules and abscesses that characterize the disease. This is a review of the major mediators involved in the recruitment of neutrophils to sites of active inflammation, including bacterial components (endotoxins, exotoxins, capsule fragments, etc.), the complement pathway anaphylatoxins C3a and C5a, tumour necrosis factor-alpha, interleukin (IL)-17, IL-8 (CXCL8), IL-36, IL-1, lipocalin-2, leukotriene B4, platelet-activating factor, kallikreins, matrix metalloproteinases, and myeloperoxidase inhibitors. Pharmacological manipulation of the various pathways involved in the process of neutrophil recruitment and activation could allow for successful control and stabilization of HS lesions and the remission of active, severe flares.

Comorbidity screening in hidradenitis suppurativa: Evidence-based recommendations from the US and Canadian Hidradenitis Suppurativa Foundations

Background:

Hidradenitis suppurativa (HS) is associated with comorbidities that contribute to poor health, impaired life quality, and mortality risk.

Objective:

To provide evidence-based screening recommendations for comorbidities linked to HS.

Methods:

Systematic reviews were performed to summarize evidence on the prevalence and incidence of 30 comorbidities in patients with HS relative to the general population. The screening recommendation for each comorbidity was informed by the consistency and quality of existing studies, disease prevalence, and magnitude of association, as well as benefits, harms, and feasibility of screening. The level of evidence and strength of corresponding screening recommendation were graded by using the Strength of Recommendation Taxonomy (SORT) criteria.

Results:

Screening is recommended for the following comorbidities: acne, dissecting cellulitis of the scalp, pilonidal disease, pyoderma gangrenosum, depression, generalized anxiety disorder, suicide, smoking, substance use disorder, polycystic ovary syndrome, obesity, dyslipidemia, diabetes mellitus, metabolic syndrome, hypertension, cardiovascular disease, inflammatory bowel disease, spondyloarthritis, and sexual dysfunction. It is also recommended to screen patients with Down syndrome for HS. The decision to screen for specific comorbidities may vary with patient risk factors. The role of the dermatologist in screening varies according to comorbidity.

Limitations:

Screening recommendations represent one component of a comprehensive care strategy.

Conclusions:

Dermatologists should support screening efforts to identify comorbid conditions in HS.

Prevalence of inflammatory bowel disease among pediatric patients with hidradenitis suppurativa and the potential role of screening with fecal calprotectin

BACKGROUND/OBJECTIVES

Previous studies have demonstrated an increased prevalence of inflammatory bowel disease (IBD) in adults with hidradenitis suppurativa (HS). Whether the same association exists in pediatric patients is unknown. Fecal calprotectin (FC) is used to screen and monitor disease activity in IBD. There are no data on using FC to screen for IBD in pediatric patients with HS. Study objectives include a) assessing the prevalence of IBD among pediatric patients with HS; b) characterizing the IBD phenotype among pediatric patients with HS; and c) describing the use of FC as a screening tool for IBD in this population.

DESIGN/METHODS

This retrospective chart review was conducted at a single academic children's hospital. We included patients ≤18 years old diagnosed with HS between 2013 and 2018.

RESULTS

We identified 109 pediatric patients with HS. Six patients (6/109, 5.5%) were diagnosed with IBD, 83.3% (5/6) classified as ulcerative colitis. Almost half (53/109, 48.6%) of HS patients had gastrointestinal symptoms; of those, 11.3% (6/53) were diagnosed with IBD. FC was obtained in 8.3% (9/109) of HS patients overall and 66.7% (4/6) of HS patients diagnosed with IBD. Among patients with gastrointestinal symptoms, FC was obtained in 17.0% (9/53); endoscopy was performed in 24.5% (13/53). FC was elevated in all patients with IBD with an FC level. Of those with elevated FC, 80.0% (4/5) had IBD.

CONCLUSIONS

Pediatric HS may be associated with an increased prevalence of IBD suggesting that more widespread screening for IBD may be indicated. FC is infrequently used but may be a useful screening tool.

Hidradenitis suppurativa; classification, remedies, etiology, and comorbidities; a narrative review

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that is more common in females, especially during puberty and menopause. These inflammatory lesions include painful deep-seated nodules and abscesses, draining sinus tracts, and fibrotic scars. This article is a narrative review to explain whole disease aspects, including complication, causes, epidemiology, history, classification, prognosis, comorbidities, the effect of sex hormone, and potent treatments. Most patients with HS, who are not aware of their primary disease, visit primary care physicians to superinfection lesions instead of specialists. If these physicians suspect HS, their illness will not get misdiagnosed. This brief and comprehensive information in this article may help doctors to decide better about the same situation.

[CME Dermatology 23: Hidradenitis suppurativa]

CME Dermatology 23: Hidradenitis suppurativa Abstract. Hidradenitis suppurativa (Acne inversa) is a chronic skin disease characterized by recurrent inflammatory nodules, abscesses, and scarring mainly in the intertriginous areas. The prevalence is estimated to be 0.05 to 4.1 % worldwide, with women being more commonly affected. The exact pathogenesis remains unknown, but hair follicle occlusion and inflammation seem to be the initiating events. Several epidemiological correlations with smoking and obesity as well as mutations in gamma secretase genes were described. The therapy depends on the extension of the disorder and should respect the current guidelines. Topical clindamycin is suitable for mild forms of the disease whereas moderate to severe disease requires systemic anti-inflammatory treatment. Surgical intervention is currently the only definitive treatment for hidradenitis suppurativa.

Aetiology and pathogenesis of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder. Patients develop inflamed nodules and abscesses and, at later stages of disease, epithelialized tunnels and scars in skinfolds of axillary, inguinal, gluteal and perianal areas. Quality of life is affected due to severe pain, purulent secretion, restricted mobility and systemic involvement. Genetics and lifestyle factors including smoking and obesity contribute to the development of HS. These factors lead to microbiome alteration, subclinical inflammation around the terminal hair follicles, and infundibular hyperkeratosis, resulting in plugging and rupture of the follicles. Cell-damage-associated molecules and propagating bacteria trigger inflammation and lead to massive immune cell infiltration that clinically manifests as inflamed nodules and abscesses. The immune system plays a key role also in the progression and chronification of skin alterations. Innate proinflammatory cytokines (e.g. interleukin-1β and tumour necrosis factor-α), mediators of activated T helper (Th)1 and Th17 cells (e.g. interleukin-17 and interferon-γ), and effector mechanisms of neutrophilic granulocytes, macrophages and plasma cells are involved. Simultaneously, skin lesions contain anti-inflammatory mediators (e.g. interleukin-10) and show limited activity of Th22 and regulatory T cells. The inflammatory vicious circle finally results in pain, purulence, tissue destruction and scarring. Chronic inflammation in patients with HS is also frequently detected in organs other than the skin, as indicated by their comorbidities. All these aspects represent a challenge for the development of therapeutic approaches, which are urgently needed for this debilitating disease. This scholarly review focuses on the causes and pathogenetic mechanisms of HS and the potential therapeutic value of this knowledge.

The Role of Propionibacterium acnes in the Pathogenesis of Sarcoidosis and Ulcerative Colitis: How This Connection May Inspire Novel Management of These Conditions

A lesser-acknowledged role of Propionibacterium acnes is its effect on the development of sarcoidosis. This literature review not only further explores this association but also that of Propionibacterium acnes and other inflammatory conditions, such as ulcerative colitis and pyoderma gangrenosum, acne, ulcerative colitis syndrome (PAC syndrome). This article reviews the effect that isotretinoin, a commonly used treatment of acne, has on the pathogenesis of ulcerative colitis, and the immune dysregulation and genetic susceptibility of individuals prone to developing acne, sarcoidosis, and ulcerative colitis.

Literature for this article review was obtained from PubMed by utilizing both regular keywords and medical subject heading (MeSH) subheadings for data gathering. Regular keywords were: Propionibacterium acnes, sarcoidosis, ulcerative colitis, and isotretinoin. MeSH subheadings used were: Propionibacterium acnes/immunology, Propionibacterium acnes/pathogenicity, Propionibacterium acnes/genetics, sarcoidosis/immunology, and sarcoidosis/genetics.

Following the application of inclusion and exclusion criteria, a total of 5172 publications were obtained. A total of 5086 publications were removed due to a lack of relevancy to outcomes of interest. The remaining 86 publications from all the regular and MeSH keywords were selected due to relevancy to outcomes of interest. Following this, a refined manual search was done, with the removal of duplicates, and 33 publications from PubMed were selected for review.

Following a review of these records, Propionibacterium acnes was repeatedly concluded to be a causative agent of sarcoidosis. Variable results for the association between Propionibacterium acnes and ulcerative colitis were found. Most studies showed no significant association between the use of isotretinoin and the development of ulcerative colitis. A strong overlapping role of genetic susceptibility and immune dysregulation in the pathogeneses of sarcoidosis, ulcerative colitis, and Propionibacterium acnes was found.

The epidemiology of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease defined clinically by multiple, painful inflammatory lesions occurring predominantly in flexural sites. Onset is typically soon after puberty; however, it remains unknown whether the menopause induces remission. In North American and European patients with HS the female-to-male ratio is approximately 3 : 1 but the ratio is 1 : 2 in South Korean patients. It may be that some elements of HS epidemiology cannot be generalized across all populations. Elements of HS epidemiology in the USA and Europe are well established, including strong associations with obesity and smoking, which may increase disease severity. There are associations between HS and other cardiovascular disease (CVD) risk factors, including type 2 diabetes and metabolic syndrome. People with HS have double the risk of death from CVD compared with those without HS and 1·5 times the risk compared with patients with psoriasis. Depression and anxiety are associated with HS and completed suicide rates in those with HS are more than double the rates in controls. Associations exist between HS and other chronic inflammatory conditions, particularly inflammatory bowel disease and inflammatory arthritis. Case-control studies demonstrate associations with pilonidal sinus, polycystic ovary syndrome, Down syndrome, obstructive sleep apnoea and pyoderma gangrenosum. Population-based studies using routinely collected healthcare data from the USA estimate a prevalence of 0·1%, suggesting HS is relatively uncommon. European studies include undiagnosed patients and typically estimate prevalence of 1% or more, suggesting a common condition. Resolving the controversy surrounding a greater than 10-fold difference in HS prevalence estimates remains a high priority.

Baseline Characteristics from UNITE: An Observational, International, Multicentre Registry to Evaluate Hidradenitis Suppurativa (Acne Inversa) in Clinical Practice

Background

Hidradenitis suppurativa (HS), also known as acne inversa, is a recurring, painful, chronic, and sometimes disfiguring inflammatory skin disease.

Objectives

Our objective was to report the baseline clinical characteristics, natural history, and associated outcomes of patients with HS from the ongoing, prospective, non-interventional UNITE registry that is collecting data regarding the natural history and associated outcomes of HS.

Methods

Patients with inflammatory HS lesions were enrolled, including adolescents (aged 12 to < 18 years) and adults (aged ≥ 18 years). None had participated in previous or current originator-adalimumab studies/registries. Patients received treatment consistent with site-specific, routine clinical practice. HS disease status was assessed by HS lesions and disease flare; treatment and outcomes data were collected at enrolment and every 6 months for ≤ 4 years.

Results

Enrolment (N = 594; 89.1% adults; 10.9% adolescents) occurred from 29 October 2013 to 29 December 2015 at 73 sites in 12 countries. At baseline, the majority were female (69.7%) and White (81.2%), had moderate-to-severe disease (Hurley stage II or III; 93.3%), and had undergone prior procedures/surgery for HS (68.7%). In total, 61.6% of adults and 49.2% of adolescents were obese; 40.2% of patients reported current tobacco use. Scarring due to lesions occurred in 91.2% of patients. The prevalence of comorbidities of interest was as follows: depression (13.3%), other psychiatric disorders (9.6%), inflammatory bowel disease (2.7%), diabetes (9.1%), and polycystic ovary syndrome (5.2%).

Conclusions

In this population from the UNITE HS registry, obesity and smoking were common, and disease burden was high, manifesting as multiple lesions, scarring, surgical history, and considerable comorbidities.

Electronic supplementary material

The online version of this article (10.1007/s40257-020-00504-4) contains supplementary material, which is available to authorized users.

Hidradenitis suppurativa is associated with childhood and lifetime traumatic events: a case-control study

BACKGROUND

Negative life events in childhood can increase the susceptibility to autoimmune and inflammatory diseases. Hidradenitis suppurativa (HS) is a systemic inflammatory disease affecting the apocrine sweat glands, characterized by abscesses, fistulas and inflammatory nodules. It is unknown whether adult HS is associated with traumatic events.

OBJECTIVE

To investigate the association between childhood and total lifetime traumatic events and the presence of HS.

METHODS

We conducted a matched (1 : 3) case-control study with 71 HS patients and 213 controls. Patients were matched on age, gender and level of education. Questionnaires on general and demographic information, as well as the Traumatic Experience Checklist and the Hospital Anxiety and Depression Scale, were completed.

RESULTS

The number of traumatic events (OR: 1.20 per trauma, P value < 0.05), and childhood traumatic events (yes vs. no, OR 3.59, P value < 0.05) and the number of childhood traumatic events (OR 1.35 per trauma, P value < 0.05) were correlated with an increased risk of developing HS. Detailed analysis showed that childhood emotional traumatic events (OR 5.03, P value < 0.05) were significantly associated with the development of HS.

CONCLUSION

Number of lifetime traumatic events and childhood traumatic events are associated with HS. This association is strongest for emotional childhood traumas. The increased prevalence of childhood traumas in HS patients can be one of the underlying mechanisms leading to systemic inflammation in these patients.

Characterization of comorbid conditions burdening hidradenitis suppurativa: a multicentric observational study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, disabling, inflammatory skin disorder that primarily affects the hair follicle localized at the apocrine-gland-bearing areas of the body, including axillary, inguinal, buttocks, and anogenital areas, and it may be associated with a wide array of comorbid conditions. This study aimed to described comorbid conditions affecting HS patients and to detect any correlation with disease severity.

METHODS

Analyzing clinic database, we included all charts of patients visited at the HS outpatient clinic of three University Dermatologic Departments in order to describe demographic data, anthropometric measures, disease features, personal habits, clinical history, and presence of comorbidities.

RESULTS

Two hundred thirty-four patients, mostly females (62%), were enrolled in this study. Based on Hurley staging classification 41% of patients were classified as Hurley Stage I, 43.0% as Hurley II, and 16% Hurley III, with a mean mSartorius Score value of 24.7 (SD: ±19.39) and a mean AISI score value of 12.5 (SD: ±11.93). The most frequently observed comorbidities were: obesity (26.1%), polycystic ovary syndrome (PCOS) (13.8% of the overall study population and 22.3% of females), hypertension (11.9%), dyslipidemia (9.9%), type II diabetes (9.5%), thyroid disorders (9.1%), nervous system disorders (7.1%), acne (6.7%), metabolic syndrome (4.4%), and Crohn's disease (3.6%). Obesity represented a key-comorbid condition increasing the likelihood of having more severe HS and PCOS (odds ratio 3.35 and 3.74, respectively).

CONCLUSIONS

HS is associated with a variety of comorbid conditions that should be considered to perform targeted routine screening and to improve HS management.

Gastrointestinal involvement of primary skin diseases

Less is known about gastrointestinal (GI) involvement of primary skin diseases due to the difference in embryology, histology, microbiology and physiology between integument and alimentary tract. Oesophagus, following the oropharyngeal mucosa, is the most common GI segment affected by primary skin diseases, especially by eosinophilic oesophagitis, lichen planus and autoimmune bullous dermatoses like pemphigus vulgaris, mucosal membrane pemphigoid and epidermolysis bullosa acquisita. Eosinophilic oesophagitis is an emerging chronic atopic disease with oesophageal dysfunction as the typical presentation, and oesophageal narrowing, rings and stricture as late complications. Oesophageal lichen planus mainly involves the proximal to mid-oesophagus in elderly aged women with long-term oral mucosal lesions. In acute attack of pemphigus vulgaris, oesophageal involvement is not uncommon but often neglected and may cause sloughing oesophagitis (oesophagitis dissecans superficialis) with acute GI bleeding in rare cases. GI manifestation of hereditary bradykininergic angio-oedema with colicky acute abdomen mostly affects small intestine, usually in the absence of pruritus or urticaria, and is more severe and long-lasting than the acquired histaminergic form. Strong evidence supports association between inflammatory bowel disease, especially Crohn disease, and hidradenitis suppurativa/acne inversa. Patients with vitiligo need surveillance of autoimmune liver disease, autoimmune atrophic gastritis or coeliac disease when corresponding symptoms become suspect. Melanoma is the most common primary tumour metastatic to the GI tract, with small intestine predominantly targeted. Gastrointestinal involvement is not uncommon in disseminated mycosis fungoides. Extramammary Paget's disease is an intraepidermal adenocarcinoma of controversial origin, and a high association between the anogenital occurrence and colorectal adenocarcinoma has been reported. As GI tract is the largest organ system with multidimensional functions, dermatologists in daily practice should be aware of the gastrointestinal morbidities related to primary skin diseases for an early diagnosis and treatment.

Hidradenitis suppurativa

Hidradenitis suppurativa (HS; also designated as acne inversa) is a chronic inflammatory disorder, which affects the intertriginous skin and is associated with numerous systemic comorbidities. The estimated prevalence of HS is ~1% in most studied countries. Typically starting in early adulthood, cutaneous inflamed nodules, abscesses and pus-discharging tunnels develop in axillary, inguinal, gluteal and perianal body sites. The comorbidities of HS include metabolic and cardiovascular disorders, which contribute to reduced life expectancy. A genetic predisposition, smoking, obesity and hormonal factors are established aetiological factors for HS. Cutaneous changes seem to start around hair follicles and involve activation of cells of the innate and adaptive immune systems, with pivotal roles for pro-inflammatory cytokines such as tumour necrosis factor, IL-1β and IL-17. The unrestricted and chronic immune response eventually leads to severe pain, pus discharge, irreversible tissue destruction and scar development. HS has profound negative effects on patients' quality of life, which often culminate in social withdrawal, unemployment, depression and suicidal thoughts. The therapeutic options for HS comprise antibiotic treatment, neutralization of tumour necrosis factor and surgical intervention together with lifestyle modification. Nevertheless, there is an enormous need for awareness of HS, understanding of its pathogenesis and novel treatments.

Overall and Subgroup Prevalence of Crohn Disease Among Patients With Hidradenitis Suppurativa: A Population-Based Analysis in the United States

Importance

Limited evidence supports a link between hidradenitis suppurativa (HS) and Crohn disease (CD), and this relationship has not been established in the United States.

Objective

To evaluate the prevalence of CD among patients with HS in the United States and to determine the strength of association between the 2 conditions.

Design, Setting, and Participants

Cross-sectional analysis of data from 51 340 patients with HS identified using electronic health records data in the Explorys multiple health system data analytics and research platform, which includes data from more than 50 million unique patients across all US census regions.

Main Outcomes and Measures

Primary outcome was diagnosis of CD.

Results

Of the 18 455 660 total population considered, 51 340 had HS (35 000 women). Of these patients with HS, 29 010 (56.5%) were aged 18 to 44 years; 17 580 (34,2%), 45 to 64 years; and 4750 (9.3%), 65 years or older. Prevalence of CD among patients with HS was 2.0% (1025/51 340), compared with 0.6% (113 360/18 404 260) among those without HS (P < .001). Prevalence of CD was greatest among patients with HS who were white (2.3%), aged 45 to 64 years (2.4%), nonobese (2.8%), and tobacco smokers (2.3%). In univariable and multivariable analyses, patients with HS had 3.29 (95% CI, 3.09-3.50) and 3.05 (95% CI, 2.87-3.25) times the odds of having CD, respectively, compared with patients without HS. Crohn disease was associated with HS across all patient subgroups. The association was strongest for men (OR, 3.61; 95% CI, 3.24-4.03), patients aged 45 to 64 years (OR, 3.49; 95% CI, 3.16-3.85), nonobese patients (OR, 4.09; 95% CI, 3.69-4.54), and nonsmokers (OR, 3.44; 95% CI, 3.10-3.82).

Conclusions and Relevance

These data suggest that patients with HS are at risk for CD. Gastrointestinal symptoms or signs suggestive of CD warrant additional evaluation by a gastroenterologist.

Association of Hidradenitis Suppurativa With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Importance

Hidradenitis suppurativa (HS) and inflammatory bowel disease (IBD) are inflammatory diseases that share common genetic susceptibility and immunologic features. However, the link between HS and IBD has been largely unclear.

Objective

To conduct a meta-analysis to investigate the association between HS and IBD.

Data Sources

A search of the MEDLINE, Cochrane Central Register of Controlled Trials, and Embase databases yielded 397 relevant studies from inception to June 10, 2018. Two additional studies were supplied by one of the investigators.

Study Selection

Case-control, cross-sectional, or cohort studies that examined the odds or risk of IBD in patients with HS were included. No geographic or language limitations were imposed.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The Newcastle-Ottawa Scale was used to assess the risk of bias of included studies. Crohn disease and ulcerative colitis were analyzed separately, and a random-effects model meta-analysis was conducted.

Main Outcomes and Measures

The odds ratios (ORs) and hazard ratios (HRs) of IBD, Crohn disease, and ulcerative colitis in association with HS.

Results

Five case-control studies, 2 cross-sectional studies, and 1 cohort study with a total of 93 601 unique participants were included. The meta-analysis of case-control and cross-sectional studies showed significant associations of HS with Crohn disease (pooled OR, 2.12; 95% CI, 1.46-3.08) and ulcerative colitis (pooled OR, 1.51; 95% CI, 1.25-1.82). Two case-control studies found significant association of HS with IBD (ORs, 2.16 [95% CI, 1.40-3.34] and 10.00 [95% CI, 1.94-51.50]). One cohort study found an increased risk of IBD in patients with HS (HR, 5.6; 95% CI not reported; P < .002).

Conclusions and Relevance

The evidence to date supports an association of HS with IBD. These results suggest that consultation with gastroenterologists should be sought when patients with HS present with recurrent abdominal pain, chronic diarrhea, bloody stool, and body weight loss.

Clinical manifestations and quality of life in hidradenitis suppurativa patients: survey of participants from an internet support group

BACKGROUND

Hidradenitis suppurativa is a complex and infrequent autoinflammatory disease that impacts on quality of life. Its pathogenesis is not fully understood, which limits the development of curative treatments.

OBJECTIVES

To evaluate clinical and quality of life aspects of hidradenitis suppurativa patients from a social group on the Internet.

METHODS

A cross-sectional, Internet-based survey study among participants in a discussion group (Facebook) of individuals with hidradenitis suppurativa. Patients were asked to answer a questionnaire about clinical-demographic aspects and quality of life (DLQI-BRA).

RESULTS

A total of 390 individuals agreed to participate in the study, 82% of them female, median age (p25-p75), of 31 (25-37) years old, disease onset at 15 (13-23) years, family member affected in 20% of cases, overweight (BMI 29 [25-33]) kg/m2 and severe impact on quality of life (DLQI 20 [13-25]). Regarding Hurley's classification, the participants provided information that enabled classification into: I (19%), II (52%) and III (29%). More severe cases were associated with males (OR = 1.69), higher weight (BMI: OR = 1.03) non-white color (OR = 1.43) and higher frequency of other autoinflammatory diseases (OR = 1.37).

STUDY LIMITATIONS

Voluntary adherence survey with self-completion of the questionnaire by 390 from about 1600 group members.

CONCLUSIONS

Hidradenitis suppurativa patients who participated in a social network group had onset of the disease after puberty, with a predominance in females and overweight people, with great impact on the quality of life.

Evaluating patients' unmet needs in hidradenitis suppurativa: Results from the Global Survey Of Impact and Healthcare Needs (VOICE) Project

BACKGROUND

A needs assessment for patients with hidradenitis suppurativa (HS) will support advancements in multidisciplinary care, treatment, research, advocacy, and philanthropy.

OBJECTIVE

To evaluate unmet needs from the perspective of HS patients.

METHODS

Prospective multinational survey of patients between October 2017 and July 2018.

RESULTS

Before receiving a formal HS diagnosis, 63.7% (n = 827) of patients visited a physician ≥5 times. Mean delay in diagnosis was 10.2 ± 8.9 years. Patients experienced flare daily, weekly, or monthly in 23.0%, 29.8%, and 31.1%, respectively. Most (61.4% [n = 798]) rated recent HS-related pain as moderate or higher, and 4.5% described recent pain to be the worst possible. Access to dermatology was rated as difficult by 37.0% (n = 481). Patients reported visiting the emergency department and hospital ≥5 times for symptoms in 18.3% and 12.5%, respectively. An extreme impact on life was reported by 43.3% (n = 563), and 14.5% were disabled due to disease. Patients reported a high frequency of comorbidities, most commonly mood disorders. Patients were dissatisfied with medical or procedural treatments in 45.9% and 34.6%, respectively.

LIMITATIONS

Data were self-reported. Patients with more severe disease may have been selected.

CONCLUSION

HS patients have identified several critical unmet needs that will require stakeholder collaboration to meaningfully address.

Comorbidities of hidradenitis suppurativa: A review of the literature

Background

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that affects the follicular portion of folliculopilosebaceous units. It causes painful nodules, abscesses, and draining sinus tracts throughout multiple regions of the body. HS primarily affects women; the overall HS prevalence in women is three times that in men. Although cutaneous disease itself causes substantial morbidity, recent evidence has shown that HS is a systemic inflammatory disease with multiple associated comorbidities.

Objective

A review of the literature was conducted to elucidate existing information on this topic to assist in clinical decision-making for dermatologists.

Methods

A review of the literature using the PubMed database was conducted with the search term "hidradenitis suppurativa comorbidities". The search was conducted from March 3, 2019 to March 20, 2019, and yielded 55 articles, case reports, and reviews.

Results

Metabolic and cardiovascular comorbidities were the most commonly associated with HS. HS has a significant comorbidity burden beyond the skin, including metabolic, cardiovascular, endocrine, gastrointestinal, rheumatologic, and psychiatric disorders, which collectively decrease the quality of life of patients.

Conclusions

Dermatologists should be aware of these associations to encourage appropriate screening and referral for management of these disorders.