Questionnaire-based epidemiological study of hidradenitis suppurativa in Japan revealing characteristics different from those in Western countries

The Disease Burdens of Self-diagnosed Hidradenitis Suppurativa Patients in Japan: A Cross-sectional Web-based Survey

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Adopting adalimumab combined surgery in the management of moderate to severe hidradenitis suppurativa: Experience from a single medical center in southern Taiwan

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder primarily affecting the intertriginous and anogenital regions. Guidelines recommend various treatments for HS, including biologic agents like adalimumab for moderate to severe cases. Adalimumab is a type of human monoclonal IgG1 antibody designed to target tumor necrosis factor α. Recent studies have shown the effectiveness of adalimumab, either alone or combined with surgery, in managing HS. We retrospectively analyzed the medical chart of HS patients in a southern Taiwan medical center from 2019 to 2022 and investigated clinical features and treatment response. The institutional review board at Chang Gung Medical Foundation granted approval for the study. We primarily focused on moderate to severely affected patients. One hundred and two clinically diagnosed HS patients participated, with a male-to-female ratio of 2:1 and an average age of 31.8 at diagnosis. Among them, 41.2% were in Hurley stage III and 32.4% in stage II. Nineteen patients received excision with pre-surgical adalimumab; their average age at diagnosis was 31.1, with a gender ratio of 5.3:1. Surgery was most common on the buttocks (68%), axillae (21%), and groin (10%). Excision patients were primarily in advanced stages (Hurley III 94.7%, II 5.3%) with high body mass index. Adalimumab and surgery combined yielded a 68.4% improvement rate, while 15.8% remained stable and 15.8% did not respond as expected. In addition, smoking and obesity were prevalent among patients. Adalimumab showed promising results in moderate to severe HS, with significant improvement observed in our cases. The combination of adalimumab and surgery appeared effective in advanced HS patients with larger involved areas and more tunnels. No severe adverse events were reported. However, our study was limited by its retrospective nature and the lack of a control group. Despite these limitations, our study revealed the benefits of integrating adalimumab with suitable surgical procedures in managing patients experiencing moderate to severe HS in real-world scenarios.

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.

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.

Recent advances in hidradenitis suppurativa: Role of race, genetics, and immunology

Hidradenitis suppurativa (HS) is a multifactorial chronic skin disease characterized by inflammation around the hair follicles commonly affecting intertriginous areas. The underlying pathogenesis of HS and its molecular mechanisms are largely understudied. Genetic studies in families have identified variants within the γ-secretase complex associated with HS; however, no definitive genotype-phenotype correlations have been made. The lack of knowledge regarding the intersection of genetics, immunology and environmental risk factors is a major obstacle to improving treatment for patients with HS. This article provides an overview of the role of race, genetics, and immunology in HS to provide insight into the multiple factors influencing the pathophysiology of HS.

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.

Real-world safety and effectiveness of adalimumab in patients with hidradenitis suppurativa: 12-week interim analysis of post-marketing surveillance in Japan

Hidradenitis suppurativa (HS) is a painful chronic skin disease characterized by abscesses, nodules, and tunnels in the skin. Adalimumab, a monoclonal antibody against tumor necrosis factor‐α, is approved for the treatment of HS in Europe, the USA, and Japan. This multicenter, open‐label, post‐marketing, observational study (ClinicalTrials.gov: NCT03894956) evaluated the safety and effectiveness of adalimumab in routine clinical practice in Japan (March 2019–May 2021). Patients with HS were treated with s.c. doses of adalimumab according to the dosage described in the package insert. The primary end‐point was safety (data cut‐off, December 2020). Secondary end‐points assessed effectiveness, including HS Clinical Response (HiSCR), skin pain, Dermatology Life Quality Index (DLQI), and C‐reactive protein (CRP). Here, we report 12‐week interim effectiveness results. A total of 84 eligible patients from 65 sites were enrolled; 83 patients were included in this analysis. Mean age was 42.0 years, mean body mass index was 26.9 kg/m², 78.3% of patients were male, 61.4% had Hurley stage III disease, 39.8% had a disease duration ≥10 years, and 7.2% had a family history of HS. The most common affected sites were the axilla (60.2%), buttocks (59.0%), and the inguinal and femoral regions (47.0%). Mean abscess and inflammatory nodule count was 13.0 (standard deviation, 12.0). Among patients with a comorbidity (57.8%), the most common were diabetes mellitus, hypertension, and chronic kidney disease. No patient reported a serious infection or any safety event of special interest. One patient died from a serious adverse event of cardiac failure unrelated to adalimumab. At week 12, 57.4% of patients achieved HiSCR, and significant reductions from baseline in skin pain, DLQI (both p < 0.0001), and CRP (p = 0.0029) were observed. These results support the administration of adalimumab as a well‐tolerated and effective treatment for Japanese patients with HS in real‐world clinical practice.

Overall Impairment of Quality of Life in Japanese Patients with Hidradenitis Suppurativa: Comparison with National Standard

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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.

Hidradenitis suppurativa: Disease pathophysiology and sex hormones

Hidradenitis suppurativa is a cutaneous chronic inflammatory disease that is estimated to affect about 1% of the population and caused pain, malodorous discharge, disfigurement, and poor quality of life with psychosocial problems. The typical features are recurrent painful nodules, abscesses, and sinus tracts on the axillae, groins, gluteal areas, and anogenital regions since postpuberty. Smoking and obesity are two major triggering factors of hidradenitis suppurativa. Women are prone to have hidradenitis suppurativa than men in Western countries, but the male-to-female ratio is reversed in oriental countries. The disease severity can be affected by menstruation, pregnancy, and menopause. Furthermore, the phenotypes are different among men and women with hidradenitis suppurativa. Men are prone to have buttock involvement while women are prone to have axillary, groins, and submammary lesions. This review introduces the skin appendages and pathophysiology of hidradenitis suppurativa and then focuses on the sex difference and the effects of sex hormones on hidradenitis suppurativa and current hormone-associated treatments.

Hidradenitis suppurativa in South-East Asia and East Asia

Hidradenitis suppurativa (HS) in South-East Asia and East Asia shows distinct clinical, environmental, physiological and likely genetic differences compared with the West. A male predominance is present, which may be due to differences in smoking habits. Involvement of the buttocks is common in East Asian patients, while the axillae are most commonly affected in South-East Asian patients. Metabolic comorbidities are prevalent in South-East Asian and East Asian HS patients. A family history of HS is less common than noted in Western populations. Asian ethnic subgroups deserve further study.

Hidradenitis suppurativa in East and Southeast Asian populations: a systematic review and meta-analysis

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that presents with recurrent inflammatory nodules and draining tunnels in the skin. Most HS studies have focused on Western populations, and the understanding of how HS characteristics differ in specific Asian ethnicities is poor. We conducted the first systematic review and meta-analysis to characterize HS patients from East and Southeast Asia. PubMed, Embase, and Ovid MEDLINE databases were searched from inception to June 12, 2020. English-language case-series, cross-sectional, observational, and randomized controlled trial studies investigating HS in East and Southeast Asian populations were screened by titles, abstracts, and articles in duplicate. Of 136 citations, 10 studies were included in the meta-analysis. Data on gender distribution, lesion distribution in the axilla and gluteal regions, and family history were extracted in duplicate. A random effects model was used for the meta-analysis. A total of 30,125 HS patients were included in the analysis. Most patients were male (66%, 95% CI = 60-72%). About half of Asian patients with HS develop lesions in the axilla (52%, 95% CI = 33-72%) and the buttocks (48%, 95% CI = 38-57%). Only a small subset had positive family history of HS (5%, 95% CI = 2-8%). We report an up-to-date characterization of HS in East and Southeast Asian populations and highlight differences in their Western counterparts. These results will hopefully improve understanding for how HS may manifest, lead to more personalized treatments for Asian patients with HS, and usher in a proper patient-centered approach to treating the disease.

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.

Long-term analysis of adalimumab in Japanese patients with moderate to severe hidradenitis suppurativa: Open-label phase 3 results

This phase 3, multicenter, open-label single-arm study evaluated adalimumab (ADA) in Japanese patients with moderate to severe hidradenitis suppurativa (HS). Fifteen patients received ADA 160 mg s.c. at week 0, 80 mg at week 2 and 40 mg at week 4 and every week thereafter. At any time after week 52, patients were given the option to receive 80 mg ADA every other week or remain on 40 mg every week. The primary end-point (achievement of HS Clinical Response [HiSCR] at week 24) and results up to week 24 were published previously. Secondary end-points included total abscess and inflammatory nodule (AN) count, 30% or more and 1 unit or more reduction in Patient's Global Assessment of Skin Pain Numeric Rating Scale (NRS30), modified Sartorius score and quality of life (QoL). After 12 weeks of ADA treatment, the achievement rate in HiSCR was 86.7%; HiSCR achievement rate was sustained through week 52 at 66.7%. Improvements at week 12 were also seen in the proportion of patients achieving an AN count of 0-2; NRS30 response rate among the nine patients with a baseline NRS of 3 or more; mean decrease in modified Sartorius score (61.4); and QoL as assessed by Dermatology Life Quality Index and Treatment Satisfaction Questionnaire; these improvements were maintained through 52 weeks. Similar efficacy was observed when patients switched dosing from ADA 40 mg every week to ADA 80 mg every other week. There were no new safety findings with ADA 40 mg weekly dosing during the study, and no differences in safety were found between patients who switched to 80 mg ADA every other week and patients who remained on 40 mg every week. The results of this study indicate that long-term ADA treatment is effective and well tolerated in Japanese patients with moderate to severe HS.