A Chronic Inflammatory Skin Condition Hidradenitis Suppurativa, or acne inversa, is a chronic recurrent inflammatory disorder of the skin. The condition affects areas of the body where there are apocrine glands – specifically, armpits, groin, and buttocks. It causes painful nodules, abscesses and scarring which may significantly impact the quality of life due to pain, odors caused by fluid drainage from the lesions, and emotions involved. Hidradenitis suppurativa is not contagious. It is also not caused by poor hygiene. It can improve with treatment but without any treatment, it deteriorates over time. Its prevalence is estimated to be 1-4% (Godiwalla et al., 2020; Jafari et al., 2020).

Causes and Risk Factors Although there are no clear causative factors for hidradenitis suppurativa, current research suggests that there is an interaction between genetic factors, the immune

Journal of the American Academy of Dermatology (JAAD). (This is essential for 2025/2026 medical management).

Journal of Vascular and Interventional Radiology/Journal of the European Academy of Dermatology (JEADV).

[Swiss Guidelines 2026]: Swiss S1 Guidelines for the Management of Hidradenitis Suppurativa. Dermatology (Karger).

Medscape/UpToDate Comprehensive Review 2026

[IHS4 Score 2017/2022]: International Hidradenitis Suppurativa Severity Score System (IHS4). British Journal of Dermatology.

[IHS4-55 Update]: Tzellos T, et al. Development and validation of IHS4-55, a dichotomous outcome to assess treatment effect. JEADV (2023/2024).

2025 Meta-Analysis. JAMA Dermatology (July 2025). Compares adalimumab, secukinumab, and bimekizumab.

[Real-World Data 2026]: Real-world outcomes of biologics for hidradenitis suppurativa: A systematic review and meta-analysis. JEADV (April 2026).

[The Lancet Review 2025]: Hidradenitis suppurativa: a comprehensive review of advances in diagnosis and treatment. The Lancet (Jan 2025). Focuses on follicular occlusion, systemic inflammation, and new biologics.

[StatPearls Update 2026]: Hidradenitis Suppurativa - StatPearls - NCBI Bookshelf. (Updated routinely, best for general overview and histopathology).

[2025 Year in Review]: Dermatology Times 2025 Year in Review: Hidradenitis Suppurativa Advancements. (Covers Bimekizumab long-term data and new JAK inhibitors)