Epidemiology of hidradenitis suppurativa in Germany - an observational cohort study based on a multisource approach

Approach to the Atypical Wound

The heterogeneity of atypical wounds can present diagnostic and therapeutic challenges; however, as the prevalence of atypical wounds grows worldwide, prompt and accurate management is increasingly an essential skill for dermatologists. Addressing the underlying cause of an atypical wound is critical for successful outcomes. An integrated approach with a focus on pain management and patient engagement is recommended to facilitate enduring wound closure. Advances in treatment, in addition to further research and clinical training, are necessary to address the expanding burden of atypical wounds.

Diagnoseverzögerung bei Hidradenitis suppurativa untersucht mit Daten von sozialen Medien und gesetzlichen Krankenversicherungen

Hintergrund

Die chronisch‐entzündliche Hauterkrankung Hidradenitis suppurativa (HS) führt bei Betroffenen zu ausgeprägten Schmerzen und verminderter Lebensqualität. Trotzdem vergehen oft mehrere Jahre bis zur korrekten Diagnosestellung. In dieser Analyse sollten krankheitsbedingte Erfahrungen und Wege der Patienten mit HS untersucht und der ärztlichen Sicht gegenübergestellt werden.

Patienten und Methodik

Für die Studie wurden Ergebnisse einer Befragung von Dermatologen und deren Patienten zur Versorgungsrealität bei HS in Deutschland sowie öffentliche Beiträge auf Internet‐Foren und in sozialen Medien analysiert. Zusätzlich wurden Abrechnungsdaten deutscher Krankenkassen ausgewertet.

Ergebnisse

Patienten mit HS haben eine um 43,3% reduzierte Arbeitsfähigkeit. Die Dermatologie (26,5%) war der am häufigsten konsultierte Fachbereich, die Diagnose HS wurde dabei überwiegend im stationären Bereich (43,8%) gestellt. Als häufigste alternative Diagnose bei HS‐Patienten wurden Abszesse angegeben (53,2%). Die Analyse von Wechseln zu anderen Behandlern ergab, dass diese in der Dermatologie (34,1%) und der Chirurgie (42,4%) vorwiegend innerhalb des Fachbereiches erfolgen. Überweisungen erhielt die Dermatologie mehrheitlich aus dem hausärztlichen Bereich (67,1%) allerdings nur 12,1% von Chirurgen.

Schlussfolgerungen

Die Diagnoseverzögerung und die dadurch verlängerte Krankheitsbelastung von Patienten mit HS muss dringend reduziert werden. Dazu sollte, möglichst schon als Teil des Medizinstudiums, ein über die Dermatologie hinaus reichendes Bewusstsein für die Erkrankung, ihre Erkennung und Behandlung gefördert werden.

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.

Diagnostic delay in Hidradenitis suppurativa investigated using data from social media and from statutory health insurances

BACKGROUND

The chronic inflammatory skin disease hidradenitis suppurativa (HS) leads to severe pain and reduced quality of life. Nonetheless, it often takes years until a correct diagnosis is made. In this analysis, disease-related experiences and pathways of patients with HS were investigated and compared with the physicians' perspective.

METHODS

Public posts on forums and social media as well as results of a survey conducted among dermatologists and their patients on the actual medical care reality of HS in Germany were analysed. Furthermore, claims data from German health insurance companies were evaluated.

RESULTS

Patients with HS suffer from a 43.3% reduction in working ability. Dermatology (26.5%) was the most frequently consulted specialty, with HS diagnosed predominantly in the inpatient setting (43.8%). Abscesses were described as the most frequent alternative diagnosis in HS patients (53.2%). Patient-reported changes of physicians in dermatology (34.1%) and surgery (42.4%) occurred predominantly within the specialty. Dermatology received most referrals from general practitioners (67.1%), but only 12.1% from surgeons.

CONCLUSION

There is an urgent need to reduce the delay in diagnosis and the prolonged burden of disease in patients with HS. Therefore, awareness of the disease, its detection and treatment which goes beyond dermatology should be promoted, if possible as part of medical studies.

S2k guideline for the treatment of hidradenitis suppurativa / acne inversa - Short version

The S2k guideline on hidradenitis suppurativa/acne inversa (HS/AI) aims to provide an accepted decision aid for the selection/implementation of appropriate/sufficient therapy. HS/AI is a chronic recurrent, inflammatory, potentially mutilating skin disease of the terminal hair follicle-glandular apparatus, with painful, inflammatory lesions in the apocrine gland-rich regions of the body. Its point prevalence in Germany is 0.3%, it is diagnosed with a delay of 10.0 ± 9.6 years. Abnormal differentiation of the keratinocytes of the hair follicle-gland apparatus and accompanying inflammation form the central pathogenetic basis. Primary HS/AI lesions are inflammatory nodules, abscesses and draining tunnels. Recurrences in the last 6 months with at least 2 lesions at the predilection sites point to HS/AI with a 97% accuracy. HS/AI patients suffer from a significant reduction in quality of life. For correct treatment decisions, classification and activity assessment should be done with a validated tool, such as the International Hidradenitis Suppurativa Severity Scoring System (IHS4). HS/AI is classified into two forms according to the degree of detectable inflammation: active, inflammatory (mild, moderate, and severe according to IHS4) and predominantly inactive, non-inflammatory (Hurley grade I, II and III) HS/AI. Oral tetracyclines or 5-day intravenous therapy with clindamycin are equal to the effectiveness of clindamycin/rifampicin. Subcutaneously administered adalimumab, secukinumab and bimekizumab are approved for the therapy of HS/AI. Various surgical procedures are available for the predominantly non-inflammatory disease form. Drug/surgical combinations are considered a holistic therapy method.

A center-based, ambulatory care concept for hidradenitis suppurativa improves patient outcomes and is also cost-effectiveness

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting approximately 1% of the population. The patient journey through the German health care system leads to high disease burden and substantial treatment costs. The EsmAiL study showed that an innovative, interprofessional, multimodal care-concept reduces disease activity and burden of HS compared to standard care. This paper examines the costs of treating HS in Germany and compares them with those of the innovative care concept implemented in EsmAiL.

METHODS

EsmAiL was a two-arm, multicenter, prospective randomized controlled trial including 553 adults with HS. The study was registered in the German Clinical Trials Registry (DRKS00022135). The control group (CG) remained in standard care, whereas the intervention group (IG) was referred to specialized so-called 'acne-inversa-centres (AiZ)' where patients were treated with a structured, interdisciplinary approach. The present paper analyses the treatment costs for a subpopulation based on health insurance cost data from the two largest German health insurers. Quality-Adjusted Life Years (QALY) was assessed based on Dermatology Life Quality Index (DLQI).

RESULTS

Total annual treatment costs per patient were €3,966.07 in standard care (n = 89) and €3,974.37 in the innovative care (n = 93). The costs per additional QALY amounted to €12,698.72 in the IG. Given the conventional and established threshold of €22,600 to €33,900 per QALY, the innovative treatment in AiZ proved to be cost-effective.

CONCLUSION

Treatment costs of HS are substantial and increase with disease severity. The new form of care is cost-effective and is expected to decrease costs in the long run.

Patient Preferences in the Management of Hidradenitis Suppurativa: Results of a Multinational Discrete Choice Experiment in Europe

BACKGROUND AND OBJECTIVE

Hidradenitis suppurativa is a chronic inflammatory skin disease that can lead to a substantial reduction in quality of life. Recent studies revealed high levels of unmet care needs of patients with hidradenitis suppurativa, but their preferences in treatment decision making have scarcely been investigated. This study aimed to reveal which treatment attributes adult patients with HS in Europe consider most important in treatment decision-making.

METHODS

A discrete choice experiment was conducted with adult patients with hidradenitis suppurativa in Europe to reveal which treatment attributes are most important when making treatment decisions. Participants were presented with 15 sets of two treatment options and asked for each to choose the treatment they preferred. The treatments were characterized by six attributes informed by a prior literature review and qualitative research: effectiveness, pain reduction, duration of treatment benefit, risk of mild adverse event, risk of serious infection, and mode of administration. A random parameter logit model was used to estimate patients' preferences with additional subgroup and latent class models used to explore any differences in preferences across patient groups.

RESULTS

Two hundred and nineteen adult patients with hidradenitis suppurativa were included in the analysis (90% women, mean age 38 years). For all six treatment attributes, significant differences were observed between levels. Given the range of levels of each attribute, the most important treatment attributes were effectiveness (47.9%), followed by pain reduction (17.3%), annual risk of a mild adverse event (14.4%), annual risk of a serious infection (10.3%), mode of administration (5.3%), and duration of treatment benefit (4.8%). Higher levels of effectiveness, namely a 75% or 100% reduction in the abscess and inflammatory nodule count, were preferred over levels of effectiveness primarily investigated in randomized clinical trials of hidradenitis suppurativa (a 50% reduction). Results were largely consistent across subgroups and three latent class groups were identified.

CONCLUSIONS

This study revealed the most important treatment characteristics for patients with hidradenitis suppurativa that can help inform joint patient-physician decision making in the management of hidradenitis suppurativa. Designing future hidradenitis suppurativa treatments according to stated preferences, namely, to offer higher levels of effectiveness and pain improvement without higher risks of adverse events, may increase patients' treatment concordance and lead to improved disease management outcomes.

Epidemiology and comorbidity of hidradenitis suppurativa in Korea for 17 years: A nationwide population-based cohort study

Hidradenitis suppurativa (HS) is associated with various metabolic and autoimmune diseases. The epidemiology has been analyzed in various studies worldwide. However, epidemiological data on HS for Asian populations are limited. This study aimed to analyze the change in the prevalence and incidence of HS over 17 years in South Korea using the Korean National Health Insurance Service (NHIS) database. This study also evaluated the comorbidities in patients with HS. Population-based data from the NHIS database of Korea were obtained between January 2003 and December 2019. Odds ratios were estimated to determine the association between comorbidities and HS during the study period. Hazard ratios for the risk of incident comorbidities in patients with HS were obtained using the multivariable Cox proportional hazard analysis. This study included 45 511 patients with HS and 910 220 controls matched for age, sex, insurance type, and income level. The incidence rate of HS per 1 000 000 person-years in Korea increased from 11.69 in 2003 to 78.78 in 2019. The annual prevalence per 1 000 000 people also increased from 34.68 in 2003 to 140.10 in 2019, showing a similar trend. Many comorbidities, including atopic, metabolic and end-organ, autoimmune/inflammatory, and psychiatric diseases were associated with HS at baseline. In many diseases, the risk of incident comorbidities in patients with HS was higher than that in controls. The incidence and prevalence of HS in Korea have increased over the past 17 years. Various comorbidities, including allergic diseases, hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, chronic hepatitis and cirrhosis, chronic kidney disease, inflammatory bowel diseases, rheumatoid arthritis, vitamin D deficiency, and psychiatric diseases, were associated with HS. Physicians need to keep in mind and closely monitor these comorbidities in patients with HS.

Measuring Quality of Life in Hidradenitis Suppurativa: Development and Validation of a Disease-specific Patient-reported Outcome Measure for Practice and Research

Hidradenitis suppurativa is a chronic disease that disrupts patients' physical and psychological well-being. A disease-specific measure was developed and validated for assessing health-related quality of life in hidradenitis suppurativa. After qualitative item development, the quality of life in hidradenitis suppurativa instrument was tested in 101 patients, applying convergent measures and a usability questionnaire. Descriptive and validation-specific analyses were conducted. There was no ceiling, but moderate floor effects (scores between 0 and 3.13 on a scale of 0-4). Few missing values were observed (21 of 23 items < 5%). Internal consistency was satisfying: 2 subscales with 6 and 16 items were identified (Cronbach's alpha=0.95 and 0.88). The quality of life in hidradenitis suppurativa instrument correlated significantly with all convergent criteria (including change in convergent patient-reported outcomes; p < 0.05) except for Hurley stage (p = 0.490). In conclusion, the quality of life in hidradenitis suppurativa questionnaire is an internally consistent, valid, responsive, and usable instrument to assess quality of life in patients with hidradenitis suppurativa.

Incidence, Risk Factors, and Prognosis of Hidradenitis Suppurativa Across the Globe: Insights from the Literature

Hidradenitis suppurativa, a chronic inflammatory disease of the skin, affects a patient's quality of life to a greater extent. While the disease burden, including its incidence and prevalence, has been extensively studied in the western population, there is a paucity of data from developing countries on the epidemiology of Hidradenitis suppurativa. Therefore, a general literature review was conducted to shed light on the epidemiology of Hidradenitis suppurativa across the globe. We reviewed the most recently available information on epidemiology, including incidence, prevalence, risk factors, prognosis and quality of life, complications, and associated comorbid among patients with Hidradenitis suppurativa. The estimated global prevalence of Hidradenitis suppurativa is found to be 0.00033-4.1%, with a relatively higher prevalence of 0.7-1.2% in European and US populations. Both genetic and environmental factors are associated with Hidradenitis suppurativa. Patients with Hidradenitis suppurativa have associated comorbid such as cardiovascular disease, type II diabetes mellitus, mental health issues, and sleep and sexual dysfunctions. These patients spend poor quality of life and tend to be less productive. Future studies are needed to assess the burden of Hidradenitis suppurativa in developing countries. Since the disease tends to be underdiagnosed, future studies should rely on clinical diagnosis rather than self-reporting to avoid the potential of recall bias. Attention needs to be diverted to developing countries with less amount of data on Hidradenitis suppurativa.

Phenotype Algorithms to Identify Hidradenitis Suppurativa Using Real-World Data: Development and Validation Study

BACKGROUND

Hidradenitis suppurativa (HS) is a potentially debilitating, chronic, recurring inflammatory disease. Observational databases provide opportunities to study the epidemiology of HS.

OBJECTIVE

This study's objective was to develop phenotype algorithms for HS suitable for epidemiological studies based on a network of observational databases.

METHODS

A data-driven approach was used to develop 4 HS algorithms. A literature search identified prior HS algorithms. Standardized databases from the Observational Medical Outcomes Partnership (n=9) were used to develop 2 incident and 2 prevalent HS phenotype algorithms. Two open-source diagnostic tools, CohortDiagnostics and PheValuator, were used to evaluate and generate phenotype performance metric estimates, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value.

RESULTS

We developed 2 prevalent and 2 incident HS algorithms. Validation showed that PPV estimates were highest (mean 86%) for the prevalent HS algorithm requiring at least two HS diagnosis codes. Sensitivity estimates were highest (mean 58%) for the prevalent HS algorithm requiring at least one HS code.

CONCLUSIONS

This study illustrates the evaluation process and provides performance metrics for 2 incident and 2 prevalent HS algorithms across 9 observational databases. The use of a rigorous data-driven approach applied to a large number of databases provides confidence that the HS algorithms can correctly identify HS subjects.

Epidemiology of Hidradenitis Suppurativa: Current Status

Purpose of Review

This review aimed to provide a comprehensive and current state of art about epidemiology and clinical aspects of the HS.

Recent Findings

Our search yielded 17 articles that included studies that showed a prevalence range from 0.00033 to 1.4%. Incidence data is limited. HS is more prevalent in women than in men. The highest prevalence is found in the third and fourth decade of life. The most frequent localizations are the inguinal, axillary, and perianal regions. There are associations between HS and obesity (OR 2.09), hypertension (OR 1.84), and dyslipidemia (OR 4.06), among others.

Summary

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by occlusion of hair follicles as a primary pathogenic factor. It affects areas of the body with apocrine glands, predominantly in the axillary, inguinal, intermammary, and anogenital regions. Clinically, its manifestations vary from inflammatory nodules and abscesses to the formation of sinus tracts and scarring. HS used to be considered a disorder of apocrine glands; today, it is considered a disease of the pilosebaceous unit associated with an immune imbalance in a genetically predisposed individual, thus linked to other autoimmune diseases.

Register, multicenter and genome-wide association studies in hidradenitis suppurativa

The European Hidradenitis Suppurativa Foundation (EHSF) e.V. has taken several initiatives to collaborative studies. They result from the data of the European Registry of Hidradenitis Suppurativa (ERHS) based on the knowledge obtained from the regional Northern countries (HISREG) and Italian (IRHIS) registries and the real-world data generated from claims data from insurance databases. Multicenter studies, such as the Hidradenitis Suppurativa collaborative study of subtypes (HORUS) and the Global Hidradenitis Suppurativa Atlas (GHISA) are planned to provide an ideal complement to the register studies. Most recently, the role of EHSF as a coordinator or key player is being explored in multiple genetic studies, such as a genome-wide association study (GWAS) and the exome sequencing and cellular/molecular profiling project, which will speed up gene and drug discovery in HS.

Epidemiology of skin diseases in Germany: systematic review of the current state of research - part 2: non-infectious skin diseases

The aim of this work was to systematically collect all previously published population-based epidemiological data on skin diseases in Germany. The present part 2 of the publication series deals with non-infectious skin diseases. The results on cutaneous tumor diseases (part 1) and infectious skin diseases (part 3) form the other parts of this publication series. A systematic literature search was performed using PubMed/MEDLINE for the period of the last 15 years. With the aim of including all dermatologic diseases, a diagnostic list was developed based on the ICD-11 catalogue. This list included 1,347 skin diseases and formed the basis for the search. The literature search yielded 4,650 hits, of which 72 were included in the synthesis. Among them were 37 publications on non-infectious skin diseases. Among these, psoriasis and atopic eczema were the most common. The highest lifetime prevalence was found for acne. This work is the first systematic literature review that aimed to report all available epidemiological data on skin diseases in Germany. It was found that representative data on many non-infectious diseases are not yet available. Among the included studies, there was a high heterogeneity regarding the methodology. Nevertheless, the utility of these epidemiological data is wide-ranging and can serve as a reference of various epidemiological questions.

Self-Reported Hidradenitis Suppurativa Severity: Is It Useful for Clinical Practice?

Introduction

Hidradenitis suppurativa (HS) is considered to be the most burdensome dermatosis, with a well-documented negative influence on quality of life (QoL). The patient’s perception of the disorder, assessed as the self-reported severity, has been used in other dermatoses but not in HS. The aim of this study was to evaluate the usefulness of self-reported HS severity in clinical practice.

Methods

The study was performed on a group of 130 Spanish HS patients. HS severity was assessed for all the subjects. Hurley staging and patient self-reported severity were used. Moreover, QoL impairment was evaluated using the Dermatology Life Quality Index (DLQI) and the Hidradenitis Suppurativa Quality of Life 24 (HSQoL-24) questionnaire.

Results

The severity of HS according to the Hurley staging was most commonly assessed as Hurley II (47.7%), indicating moderate disease, followed by severe disease (Hurley III, 26.9%) and mild disease (Hurley I, 25.4%). According to the patient self-reported HS severity, most of the patients reported having mild disease (76 patients, 58.5%), followed by moderate disease (31 patients, 23.8%). Only 23 patients (17.7%) assessed their disease as severe. Moreover, men reported mild disease significantly more frequently than women (70.9% and 49.3%, respectively; p = 0.014).

The self-reported HS severity correlated positively with the effect of the disease on patient QoL assessed with DLQI (r = 0.288, p < 0.001). Likewise, a strong positive correlation was found between self-reported HS severity and QoL impairment assessed with HSQoL-24 (r = 0.404, p = 0.001). No statistically significant correlation between Hurley severity stage and DLQI or HSQoL-24 was found. Moreover, there were significant differences in both DLQI and HSQoL-24 total score between different self-reported HS severities. This was not seen for any of the QoL instruments or for Hurley severity staging.

Conclusion

The results show that self-assessment severity may reflect patients’ subjective feelings more adequately than popular objective instruments, and there should be a place for its use in daily clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00701-5.

New Insights in Hidradenitis Suppurativa from a Population-based Dutch Cohort: Prevalence, Smoking Behaviour, Socioeconomic Status and Comorbidities

Background

Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin condition and is associated with several comorbidities. Previous studies report variable prevalence rates of HS, depending on the methodology. However, the exact prevalence remains unknown.

Objectives

To estimate the prevalence of HS in a large population‐based cohort in the Northern Netherlands, and to compare patients with HS to the general population, investigate characteristics and identify potential associated comorbidities.

Methods

Data were collected through a cross‐sectional survey‐based study within the Lifelines Cohort Study (n = 167 729), based on the general population located in the Northern Netherlands. A digital self‐reported questionnaire was developed consisting of validated questions for determining HS.

Results

Among 56 084 respondents, the overall prevalence of HS was 2.1% [95% confidence interval (CI) 2.0–2.2]. The respondents with HS had lower socioeconomic status than the controls (P < 0.001) and more frequently currently smoked (P < 0.001). Several new significant associations in patients with HS were revealed, such as fibromyalgia (OR 2.26, 95% CI 1.64–3.11), irritable bowel syndrome (OR 1.63, 95% CI 1.18–2.26), chronic fatigue syndrome (OR 1.72, 95% CI 1.06–2.78) and migraine (OR 1.48, 95% CI 1.11–1.96). Fibromyalgia and chronic fatigue syndrome remained significantly associated with HS in the multivariate analysis after adjusting for age, sex, body mass index, smoking status and socioeconomic status.

Conclusions

Our study showed a higher prevalence of HS in the Northern Netherlands compared with the overall estimated prevalence of 1% and identified several new associated comorbidities.

Inpatient care for skin diseases in Germany: multi-source analysis on the current and future health care needs

BACKGROUND

In Germany, skin diseases are mainly treated in the 115 dermatological hospitals.

METHODS

Health care and health economic analysis of dermatological inpatient care and prediction of future care needs based on primary and secondary data.

RESULTS

Outpatient and inpatient care for dermatologic treatment indications is predominantly provided by dermatology specialists. Inpatient treatment was provided for 833,491 cases in 2018, corresponding to 4.21 % of all inpatient cases (19,808,687). Most common treatment cases were: epithelial skin cancer (total 87,386, of which dermatology clinics 52,608), followed by melanoma (23,917/17,774), psoriasis (19,291/13,352), erysipelas (73,337/11,260), other dermatitis (12,671/10,842), atopic dermatitis (AD) (11,421/9,734), and herpes zoster (26,249/9,652). With an average length of stay of 5.69 days, dermatology hospitals were in the bottom third. The proportion of inpatient indications cared for in dermatology hospitals was highest for prurigo (95.2 %), pemphigus (94.9 %), parapsoriasis (94.6 %), pemphigoid (90.3 %), eczema other than AD (85.6 %), and AD (85.2 %). While the total number of inpatient treatment cases in Germany has increased by an average of 17.5 % between 2000 and 2018, this is the case for 26.6 % of skin diseases and over 150 % for individual ones. The projection of current to future inpatient care suggests a continued high demand for inpatient care by dermatology hospitals.

CONCLUSION

Inpatient dermatological care will continue to be an indispensable component of qualified, socially necessary care in Germany.

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

Identifying Unmet Care Needs and Important Treatment Attributes in the Management of Hidradenitis Suppurativa: A Qualitative Interview Study

Background and Objective

Hidradenitis suppurativa (HS) is an inflammatory skin disease with a profound effect on patients’ quality of life. The patient’s journey to manage HS is often complex and unsuccessful, which motivates the aim of this research to gain insight into unmet needs and relevant treatment considerations from the perspective of patients and healthcare professionals (HCPs).

Methods

Individual semi-structured interviews were conducted with patients and HCPs experienced in treating HS to understand the perceived unmet care needs and to identify important treatment attributes. Prioritization of the five most important treatment attributes allowed elicitation of their relative importance.

Results

Interviews with 12 patients and 16 HCPs revealed 16 areas of unmet needs either related to treatment outcomes or the care process and 13 important treatment attributes. The most frequently reported unmet needs by patients and HCPs were lacking quality-of-life improvement, low treatment effectiveness, inadequate pain control, low disease awareness, and delayed diagnosis. Patients expressed unique concerns relating to pain management, access to HS specialists, and wound care guidance and costs, which HCPs did not. Treatment attributes related to effectiveness were considered most important by patients and HCPs. Patients additionally emphasized a strong preference for improved pain management.

Conclusions

Current HS treatments and care processes leave patients and HCPs with a high level of unmet need. It is critical to consider patients’ and HCPs’ perspectives when designing appropriate HS care as perceived unmet needs differ. Further quantitative preference elicitation studies are needed to assess the trade-offs between important care needs and treatment attributes.

Metabolic Disorders/Obesity Is a Primary Risk Factor in Hidradenitis Suppurativa: An Immunohistochemical Real-World Approach

BACKGROUND

Hidradenitis suppurativa (HS) is an inflammatory, potentially scarring disease of the hair follicle, affecting the apocrine gland-bearing skin areas. The major comorbid disorders associated with the occurrence or the aggravation of the disease are obesity and smoking. Numerous efforts to dissociate these factors led to controversial results.

OBJECTIVES

To assess the importance of metabolic disorders/obesity, smoking/environmental toxins, and inflammation in HS by utilizing the differential expression of major relevant protein markers in lesional skin of obese/smoking versus non-obese/non-smoking HS patients.

METHODS

Lesional skin specimens deriving from two groups of HS patients (BMI >30 and smokers, n = 12 vs. BMI <30 and non-smokers, n = 10) were stained with antibodies raised against irisin, PPARγ, and IGF-1R, which correlate with metabolic disorders/obesity, EGFR and AhR, associated with smoking, and IL-17, IL-17R, and S100A8, as markers of inflammation.

RESULTS

Metabolic disorders/obesity-related markers exhibited marked differential expression between the two groups, while smoking-associated markers a limited one. IL-17R expression was stronger in obese/smokers, and S100A8 staining exhibited intense strong immunoreactivity in both groups without significant difference.

CONCLUSIONS

The notion that obesity plays a role in HS development appears to be supported by the prominent regulation of the associated lesional biomarkers. Tobacco smoking might contribute less to HS than previously suspected.

Patient experiences with hidradenitis suppurativa: the Hidradenitis Patient Experience survey

BACKGROUND

Better understanding of the experience of people living with hidradenitis suppurativa (HS) is essential to identify gaps in current patient care and inform healthcare decision-making.

AIM

To describe the patient experience of individuals with HS, including their path to diagnosis, symptom control, treatments, healthcare utilization, patient needs and impact on quality of life.

METHODS

The Hidradenitis Suppurativa Patient Experience survey was created, extensively reviewed and disseminated through engaging HS-related patient organizations, physician groups and social media groups.

RESULTS

In total, 537 respondents completed the survey; the mean age was 38 years (range 14-73 years) and 95% (510 of 537) were female. The mean number of treatment types per respondent was 15, and included antibacterial soaps (93.3%; 431 of 462), avoidance of tight clothing (90.9%; 419 of 462), use of oral antibiotics (79.7%; 368 of 462), nonprescription drugs (79.7%; 368 of 462) and topical antibiotics (77.1%; 356 of 262). Pain was poorly controlled in 46% of respondents (184 of 401). HS had a negative impact on the ability to work and attend school for 81% of respondents (337 of 415), with 59% (245 of 415) missing at least 2 days of work a month and 16% (66 of 415) missing > 11 days of work. The mean number of misdiagnoses per respondent was three and the median time to diagnosis was 10 years.

CONCLUSION

Individuals with HS experience a delay in diagnosis and have suboptimal control of the disease. We propose 11 recommendations to improve diagnosis, treatment and quality of life for individuals living with HS.

[Epidemiology, patient quality of life, and treatment costs of hidradenitis suppurativa/acne inversa]

Hidradenitis suppurativa/acne inversa (HS) is associated with numerous and relevant restrictions on the quality of life for those affected and their relatives. The exact prevalence of HS varies significantly across studies, but it is likely to be higher than suggested in previous publications. HS care is associated with high costs for the healthcare system and for those affected. The introduction of biologic therapy has led to additional costs, but also to considerable additional benefits in terms of care. In view of the complexity of diagnostics and therapy, there is a particular need for optimized care concepts in order to reduce the burden on those affected, their relatives and the healthcare system.

The measurement performance of the EQ-5D-5L versus EQ-5D-3L in patients with hidradenitis suppurativa

PURPOSE

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that affects up to 1% of the population in Europe. The EQ-5D is the most commonly used generic instrument for measuring health-related quality of life among HS patients. This study aims to compare the measurement properties of the two adult versions of EQ-5D (EQ-5D-3L and EQ-5D-5L) in patients with HS.

METHODS

We recruited 200 consecutive patients with HS (mean age 37 years, 38% severe or very severe HS) to participate in a multicentre cross-sectional survey. Patients completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16 questionnaires.

RESULTS

More than twice as many different health state profiles occurred in the EQ-5D-5L compared to the EQ-5D-3L (101 vs. 43). A significant reduction in ceiling effect was found for the mobility, self-care and usual activities dimensions. A good agreement was established between the EQ-5D-3L and EQ-5D-5L with an intraclass correlation coefficient of 0.872 (95% CI 0.830-0.903; p < 0.001) that was confirmed by a Bland-Altman plot. EQ-5D-5L improved both the absolute and relative informativity in all dimensions except for anxiety/depression. EQ-5D-3L and EQ-5D-5L demonstrated similar convergent validity with DLQI and Skindex-16. EQ-5D-5L was able to better discriminate between known groups of patients based on the number of comorbidities and disease severity (HS-Physician's Global Assessment).

CONCLUSION

In patients with HS, the EQ-5D-5L outperformed the EQ-5D-3L in feasibility, ceiling effects, informativity and known-groups validity for many important clinical characteristics. We recommend using the EQ-5D-5L in HS patients across various settings, including clinical care, research and economic evaluations.

Is There a Role for Therapeutic Drug Monitoring in Patients with Hidradenitis Suppurativa on Tumor Necrosis Factor-α Inhibitors?

Tumor necrosis factor-α inhibitors, adalimumab and infliximab, are at the forefront of biologic therapy for the management of moderate-to-severe hidradenitis suppurativa, with adalimumab as currently the only approved medication for this condition. In treating patients, primary or secondary lack of response (also termed suboptimal response) is a major burden for both patients and healthcare systems and is a challenge with biologics in part owing to the development of anti-drug antibodies following treatment. To overcome this, therapeutic drug monitoring may be conducted proactively or reactively to a patient's suboptimal response guided by measurements of trough serum drug concentrations and levels of anti-drug antibodies. While strong evidence to support the utility of therapeutic drug monitoring exists in patients with inflammatory bowel disease, current information is limited in the context of hidradenitis suppurativa. We sought to summarize the available evidence and to present the role of therapeutic drug monitoring and other dose optimization strategies in improving clinical response in patients with hidradenitis suppurativa treated with tumor necrosis factor-α inhibitors.

Epidemiology of hidradenitis suppurativa in Taiwan: A 14-year nationwide population-based study

Hidradenitis suppurativa (HS), also called acne inversa, is an inflammatory skin disease, which causes HS patients to suffer from recurrent symptoms and severe comorbidities. The aim of this article was to provide evidence on the epidemiology of HS in Taiwan through a retrospective population-based cohort study. The patients with International Classification of Diseases, Ninth Revision, Clinical Modification code 705.83 and Anatomical Therapeutic Chemical codes for HS treatments from 2000 to 2013 in the National Health Insurance Research Database, which covers 99.9% Taiwanese residents, were enrolled in this 14-year nationwide population-based cohort study. The age- and sex-standardized prevalence, incidence, and the prescription pattern for HS were analyzed. The annual percent change (APC) was used to estimate the trend of prevalence and incidence of HS from 2000 to 2013. During 2000-2013 in Taiwan, the 14-year period prevalence rate was 185.6/100 000 (95% confidence interval [CI], 177.3-194.3) with an APC of -2.96% (95% CI, -1.73 to -4.17) and the mean annual adjusted incidence rate from 2001 to 2013 was 11.8/100 000 (95% CI, 11.2-12.5) with an APC of -4.65% (95% CI, -3.32 to -5.95). Female : male ratio was 0.92 and the most common onset age was 15-24 years. Major treatments were systemic corticosteroids, systemic antihistamines, systemic antibiotics, and topical antibiotics. An increasing tendency of using systemic antibiotics was noted. In Taiwan, decreasing incidence and prevalence of HS was shown during 2000-2013. Relatively lower incidence and prevalence were noted compared to Western countries. Male predominance was revealed, and the use of systemic antibiotics became the mainstream in treatment for HS.

Phenotypes and Pathophysiology of Syndromic Hidradenitis Suppurativa: Different Faces of the Same Disease? A Systematic Review

<b><i>Background:</i></b> There is growing evidence that (certain) hidradenitis suppurativa (HS) comorbidities comprise syndromes including HS as a key cutaneous manifestation. These apparently autoinflammatory syndromes and their diagnostic delay might have detrimental effects on affected patients. <b><i>Methods:</i></b> A systematic review was performed on the databases MEDLINE, EMBASE, and CENTRAL utilizing a standardized extraction form according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. <b><i>Results:</i></b> Sixty-four eligible articles on syndromic HS were retrieved. The identified syndromes included already described ones (pyoderma gangrenosum-acne-suppurative hidradenitis, pyogenic arthritis-pyoderma gangrenosum-acne-suppurative hidradenitis, psoriatic arthritis-pyoderma gangrenosum-acne-suppurative hidradenitis, pyoderma gangrenosum-acne vulgaris-hidradenitis suppurativa-ankylosing spondylitis, synovitis-acne-pustulosis-hyperostosis-osteitis) and further novel symptom constellations. Cutaneous signs, including HS lesions, usually precede signs from other organs. The cutaneous signs of a considerable proportion of patients appear refractory to conventional treatment, and monotherapy with biologics does not suffice to sustain remission. <b><i>Conclusion:</i></b> The results are subsequently discussed with focus on the pathophysiology and treatment of the detected syndromes. The dermatologist’s role in the precise diagnosis and early treatment administration of HS is pivotal. The purpose of the treatment should be the effective prevention or delay of the autoinflammatory march and its irreversible consequences.

Clinical selection criteria in new clinical trials of hidradenitis suppurativa: External validity and implications on the daily clinical practice

INTRODUCTION

There are an increasing number of biologic drugs in the pipeline for treating hidradenitis suppurativa (HS). Clinical trials for these drugs usually share the same clinical selection criteria.

OBJECTIVES

(a) To describe the clinical profile of HS patients receiving first-line biologic treatment in an HS clinic setting, (b) to assess how this population would meet clinical criteria to participate in a clinical trial, and (c) to assess treatment effectiveness at week 16 in eligible vs non-eligible patients.

METHODS

Prospective observational study. Patients were grouped according to their eligibility for clinical trials. The effectiveness of adalimumab was assessed by HiSCR, IHS4-category-change and a-50%-reduction on IHS4 at week 16.

RESULTS

Thirty-eight patients were included in the study: eight (21.05%) were eligible for clinical trials and 30 (78.95%) were not. The main reason for non-eligibility was not having an AN count ≥5. Both groups presented similar number of draining tunnels. Effectiveness at week 16 was lower in non-eligible than eligible patients when evaluated by HiSCR-response but similar if evaluated by the IHS4-category-change or the 50%-reduction in IHS4.

CONCLUSION

In our population, the external validity of current eligibility criteria for clinical trials is low. Most patients receiving adalimumab in real-life setting would not be eligible for clinical trials.

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.

Validity of EQ-5D-5L, Skindex-16, DLQI and DLQI-R in patients with hidradenitis suppurativa

BACKGROUND

Numerous generic, skin- and disease-specific health-related quality of life (HRQoL) measures are available for patients with hidradenitis suppurativa (HS). Yet, robust psychometric evidence is lacking in many aspects of these outcome measures.

OBJECTIVES

We sought to determine convergent and known-groups validity of multiple generic and skin-specific HRQoL measures and to identify predictors of impaired HRQoL in patients with HS.

METHODS

Between 2017 and 2019, a multicentre cross-sectional study was carried out involving 200 consecutive HS patients. HRQoL outcomes included the EQ-5D-5L, EQ visual analogue scale (EQ VAS), Skindex-16, Dermatology Life Quality Index (DLQI) and DLQI-Relevant (DLQI-R). Disease severity was graded by HS-Physician's Global Assessment (HS-PGA) scale and the Modified Sartorius scale (MSS).

RESULTS

Overall, 77%, 56%, 51%, 46% and 28% reported problems in the pain/discomfort, usual activities, anxiety/depression, mobility and self-care dimensions of EQ-5D-5L. Mean ± SD EQ VAS, DLQI and DLQI-R scores were 64.29 ± 22.68, 11.75 ± 8.11 and 12.19 ± 8.33, respectively. Skindex-16 responses indicated that the emotional burden of HS (64.55 ± 29.28) far exceeded those of functioning (49.40 ± 34.70) and physical symptoms (46.74 ± 29.36). EQ-5D-5L, EQ VAS, DLQI, DLQI-R and Skindex-16 total scores had moderate or strong correlations with each other (range: |0.487| to |0.993|), weak or moderate correlations with HS-PGA (|0.350| to |0.433|) and weak correlations with MSS (|0.324| to |0.389|). DLQI-R slightly outperformed DLQI both in terms of convergent and known-groups validity. Being female, lower education level, more severe disease and genital involvement were associated with worse HRQoL (P < 0.05).

CONCLUSION

This study provides high-quality evidence that among skin-specific outcomes, the DLQI, DLQI-R and Skindex-16, and among generic instruments, the EQ-5D-5L are suitable to be used in HS patients. In future research, we recommend the use of existing well-validated HRQoL tools instead of developing new measures for each study. The development of composite measures that combine physician- and patient-reported outcomes is not supported by evidence in HS. [Correction added on 25 July 2020, after first online publication: in the Abstract section, the ± signs were missing and have been added to this version.].

Hidradenitis suppurativa in paediatric patients: a retrospective monocentric study in Germany and review of the literature

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent, debilitating skin disease of the hair follicle affecting apocrine glands-rich areas of the body. The disease usually occurs after puberty leading to painful nodules, abscesses, tunnels and scarring. Although uncommonly, HS can also occur in children and adolescents.

OBJECTIVE

Our objective was to describe the epidemiology, characteristics, predisposing factors and clinical course of HS in paediatric patients.

METHODS

The retrospective cohort study included patients with HS, who have been diagnosed in Dessau Medical Center and reported development of HS during childhood or adolescence, fulfilled the diagnostic criteria for HS and had a follow-up period of at least one year. A systematic review was conducted on MEDLINE, EMBASE and CENTRAL on 19 March 2020 using the terms 'hidradenitis' or 'acne inversa' together with the terms 'children', 'paediatric' and 'adolescence'.

RESULTS

Twenty paediatric patients [1 child (0.22%), 19 adolescents (4.25%)] were detected out of 447 patients evaluated (4.5%) with a male to female ratio of 1.86 : 1. The median age at diagnosis was 17 years [interquartile range (IQR) 16-18] and the median age at onset 15 years (IQR: 14-16.5). The majority of the patients suffered from moderate disease were overweight or obese and non-smokers. The most common comorbid disorder was acne vulgaris. The systematic review revealed reports with data heterogeneity and lack of systematic documentation of specific demographic characteristics. Most paediatric patients were female, obese and non-smokers, with considerable comorbid disorders.

CONCLUSIONS

Hidradenitis suppurativa in Germany may affect children and adolescents exhibiting a particular phenotype of mainly male non-smokers.

Hidradenitis Suppurativa and Concurrent Psoriasis: Comparison of Epidemiology, Comorbidity Profiles, and Risk Factors

Introduction

Hidradenitis suppurativa (HS) is a chronic, debilitating, and inflammatory skin disease. The epidemiology of HS varies greatly, with an estimated prevalence ranging from 0.03% to 4% worldwide. Similar to psoriasis (PsO), HS also exhibits a systemic inflammatory nature with a spectrum of systemic comorbidities. A large health insurance claims (HICs) database is analyzed to determine the demography and epidemiology of HS, PsO, and HS with concurrent PsO (HS-PsO) patients. Furthermore, the comorbidity profiles, including the comorbidity risk of these patient populations, are analyzed.

Methods

This is a noninterventional retrospective analysis of anonymized HICs data using a subset of the Institute of Applied Health Research Berlin (InGef) database. The primary outcome is the prevalence and incidence of HS, PsO, and HS-PsO. Secondary outcomes include comorbidity profiles and a comorbidity risk analysis.

Results

The prevalence and incidence of HS were 0.0681% and 0.0101%, respectively. The prevalence of HS-PsO was 0.004% (6% of the total HS population). HS patients frequently suffered from arterial hypertension (45%), nicotine dependence (46%), obesity (41%), and depression (36%), which were more common in HS-PsO patients compared with HS alone. HS patients had an increased prevalence of metabolic, psychiatric, immune-mediated, and cardiovascular diseases, e.g., overweight/obesity [odds ratio (OR): 2.65, 95% confidence interval (CI) 2.37–2.96], depression (OR: 1.55, 95% CI 1.42–1.76), or seronegative rheumatoid arthritis (OR: 2.82, 95% CI 1.61–4.94) compared with the overall population. The increased risk of myocardial infarction in HS patients (OR: 4.1, 95% CI 3.5–4.8, adjusting for age/sex) was largely attributed to patient’s current smoking status (OR: 1.1, 95% CI 0.8–1.5, adjusting for smoking/age/sex).

Conclusions

HS patients show a broad spectrum of inflammatory and metabolic syndrome-related comorbidities, with an increased risk by concurrent PsO. Important for clinical practice, the elevated cardiovascular risk of HS patients can be largely attributed to smoking.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00401-y) contains supplementary material, which is available to authorized users.

Lipidomics Profiling of Hidradenitis Suppurativa Skin Lesions Reveals Lipoxygenase Pathway Dysregulation and Accumulation of Proinflammatory Leukotriene B4

Hidradenitis suppurativa (HS) is a chronic, recurring inflammatory dermatosis characterized by abscesses, deep-seated nodules, sinus tracts, and fibrosis in skin lesions around hair follicles of the axillary, inguinal, and anogenital regions. Whereas the exact pathogenesis remains poorly defined, clear evidence suggests that HS is a multifactorial inflammatory disease characterized by innate and adaptive immune components. Bioactive lipids are important regulators of cutaneous homeostasis, inflammation, and resolution of inflammation. Alterations in the lipid mediator profile can lead to malfunction and cutaneous inflammation. We used targeted lipidomics to analyze selected omega-3 and omega-6 polyunsaturated fatty acids in skin of patients with HS and of healthy volunteers. Lesional HS skin displayed enrichment of 5-lipoxygenase (LO)‒derived metabolites, especially leukotriene B4. In addition, 15-LO‒derived metabolites were underrepresented in HS lesions. Changes in the lipid mediator profile were accompanied by transcriptomic dysregulation of the 5-LO and 15-LO pathways. Hyperactivation of the 5-LO pathway in lesional macrophages identified these cells as potential sources of leukotriene B4, which may cause neutrophil influx and activation. Furthermore, leukotriene B4-induced mediators and pathways were elevated in HS lesions, suggesting a contribution of this proinflammatory lipid meditator to the pathophysiology of HS.