Hidradenitis Suppurativa
Chronic recurrent follicular occlusive disease of intertriginous areas with painful nodules, abscesses, sinus tracts, and scarring.
Also known as: hidradenitis suppurativa, HS, acne inversa, Verneuil disease
Overview
A chronic, recurrent, inflammatory follicular occlusive disorder presenting with painful deep-seated nodules, abscesses, sinus tracts, and dermal scarring in intertriginous areas (axillae, inguinal, gluteal, inframammary, perianal).
Epidemiology
Prevalence ~1% (likely underestimated; often misdiagnosed for years). Female predominance 3:1. Onset typically after puberty, peak ages 20-40. Higher prevalence in African American populations and patients with obesity, smoking, and metabolic syndrome.
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Risk factors
- Smoking (90% of patients are current or former smokers) — strongest modifiable risk factor
- Obesity (mechanical friction, hormonal milieu)
- Family history (~30%) — autosomal dominant with variable penetrance in some kindreds (γ-secretase mutations)
- Female sex; menstruation may worsen flares
- Metabolic syndrome, type 2 diabetes, PCOS
- Acne, inflammatory bowel disease (Crohn > UC), spondyloarthropathy associations
Pathophysiology
Follicular hyperkeratinization and dilatation in apocrine gland-bearing skin → follicular occlusion → rupture into dermis → robust neutrophilic inflammation, sinus tract formation, and scarring. NOT a primary apocrine gland disease (older name 'apocrinitis' is incorrect). TNF-α, IL-17, IL-1β drive inflammation; γ-secretase / Notch pathway implicated in familial forms.
Clinical presentation
Symptoms
- Painful recurrent nodules and abscesses, often draining purulent foul-smelling discharge
- Pruritus, burning, stinging
- Sleep disturbance, dyspareunia, gait disturbance, work absences
- Significant pain — worst-rated chronic dermatologic disease in quality of life surveys
Signs / physical exam
- Primary lesions: tender, deep-seated, dermal/subcutaneous inflammatory nodules and abscesses
- Secondary lesions: open comedones (double-headed 'tombstone' comedones — pathognomonic), sinus tracts (interconnecting tunnels), hypertrophic and atrophic scars, contractures, lymphedema
- Distribution: axillae (most common), inguinal folds, perianal/perineal, buttocks, inframammary, submammary; less commonly nape, retroauricular, scalp
- Lesions tend to be bilateral and symmetric
- Hurley staging (clinical):
- • I: solitary or multiple abscesses, NO sinus tracts or scarring
- • II: recurrent abscesses with sinus tracts and scarring, separated by normal skin
- • III: diffuse or near-diffuse involvement, multiple interconnected sinus tracts and abscesses across entire area
Classic findings
Recurrent abscesses + sinus tracts + bridged scarring in axillae and groin; double-comedones.
Differential diagnosis
- Cutaneous abscess / furunculosis — Single acute abscess, not recurrent in same site, no sinus tracts; staphylococcal
- Cystic acne / acne conglobata — Comedones present (HS lacks except 'double comedones'), trunk/face distribution
- Crohn disease (metastatic / fistulating) — Perianal fistulas + GI symptoms; can overlap with HS
- Pilonidal disease — Sacrococcygeal area, with hair tuft; not symmetric or multifocal
- Granuloma inguinale (donovanosis) — Genital ulcers, slow growth, geographic exposure; Donovan bodies on smear
- Lymphogranuloma venereum — Groove sign with bubo formation; serotype L1-L3 chlamydia
- Steatocystoma multiplex — Multiple small cysts on chest/axillae, no inflammation or sinus tracts
- Actinomycosis — Chronic sinus tracts with 'sulfur granules'; Actinomyces israelii
Diagnostic workup
Diagnostic criteria
All three required (Dessau criteria): (1) typical lesions (nodules, abscesses, sinus tracts, scars), (2) typical locations (intertriginous), (3) chronic relapsing course.
Labs
- Clinical diagnosis — no required labs
- CBC, CRP, ESR (elevated during flares)
- Bacterial culture if secondary infection or atypical presentation (cultures often polymicrobial or sterile; routine antibiotics target empirically)
- Screen comorbidities: metabolic syndrome (lipid panel, HbA1c), depression
- Skin biopsy in atypical cases; rule out Crohn-related disease
Imaging
- Ultrasound (high-frequency) — assesses sinus tract extent, often used to plan surgery
- MRI for complex perineal/perianal disease and Crohn overlap
- Sinography in selected presurgical cases
Diagnostic algorithm
| Hurley Stage | Clinical Features | Preferred Therapy |
|---|---|---|
| I (mild) | Solitary/multiple abscesses; NO sinus tracts/scarring | Topical clindamycin; doxycycline; antiseptic washes; lifestyle |
| II (moderate) | Recurrent abscesses + sinus tracts/scars, separated by normal skin | Clindamycin + rifampin; adalimumab/secukinumab; localized excision/deroofing |
| III (severe) | Diffuse interconnected sinus tracts and abscesses | Biologic therapy + wide local excision; multidisciplinary care |
Treatment
First-line
- Lifestyle: smoking cessation (most impactful intervention), weight reduction, loose breathable clothing, avoid friction/shaving
- Daily antiseptic wash: chlorhexidine 4%, dilute bleach baths, benzoyl peroxide 5-10%
- Topical clindamycin 1% solution BID for mild Hurley I disease
- Hurley I-II: oral tetracycline antibiotic — doxycycline 100 mg BID × 12 weeks (anti-inflammatory dose) OR minocycline
- Hurley II refractory or moderate-severe: combination oral clindamycin 300 mg BID + rifampin 300 mg BID × 10-12 weeks
- Biologic therapy (Hurley II-III or refractory): adalimumab 160 mg loading → 80 mg week 2 → 40 mg weekly (FDA-approved); secukinumab (FDA-approved 2023); bimekizumab (recent approval)
- Hormonal therapy in women: combined oral contraceptive (anti-androgenic — drospirenone/EE), spironolactone 50-200 mg/day, metformin
- Intralesional triamcinolone 5-10 mg/mL for individual acute nodules
- Pain control: acetaminophen, NSAIDs, gabapentin/pregabalin for neuropathic component; avoid chronic opioids
Severe Hurley III / extensive sinus disease
- Wide local excision of involved areas with secondary intention healing or split-thickness grafting — definitive for Hurley III in affected region
- Deroofing of sinus tracts (preferred over excision when possible)
- Combine with biologic therapy preoperatively to reduce inflammation
- Multidisciplinary care: dermatology, plastic surgery, pain, mental health
Acute abscess
- Incision and drainage for relief (recognize recurrence is the rule; not curative)
- Intralesional triamcinolone immediately after I&D
- Punch debridement of inflamed nodules
Second-line / adjunct
- Oral retinoids: acitretin or isotretinoin (limited evidence for HS but used in some)
- Dapsone, colchicine, zinc supplementation (limited evidence)
- Cyclosporine, methotrexate for refractory cases
- JAK inhibitors (upadacitinib) — emerging data
- Laser hair removal (Nd:YAG) reduces follicular occlusion in affected sites
Complications
- Severe pain, depression, suicidality (rates exceed other chronic dermatoses)
- Sexual dysfunction, infertility (genital scarring)
- Lymphatic obstruction, lymphedema
- Fistulas to urethra, bladder, rectum
- Cutaneous squamous cell carcinoma in long-standing perianal/buttock disease (~3% lifetime, often aggressive)
- Anemia of chronic disease, hypoproteinemia
- Cardiovascular disease (independent risk factor), metabolic syndrome
PANCE pearls
- Recurrent painful boils in the axillae or groin = HS until proven otherwise; not 'staph infections.'
- Smoking cessation is the single most impactful lifestyle intervention — strongly counsel at every visit.
- Double-headed open comedones in affected areas are pathognomonic.
- Antibiotics work via anti-inflammatory mechanisms, not antimicrobial — failure to respond does not mean culture-directed therapy is needed.
- Long-standing perineal/buttock HS carries a real risk of cutaneous SCC — biopsy any chronic non-healing lesion.
References
- USCMS 2019 — North American Clinical Management Guidelines for Hidradenitis Suppurativa (Alikhan et al., J Am Acad Dermatol 2019)
- EHSF 2019 — European S1 Guideline for the Treatment of Hidradenitis Suppurativa (Zouboulis et al., J Eur Acad Dermatol Venereol 2015; updates ongoing)
- AAD 2024 — Joint AAD-HS Foundation Clinical Care Updates on Biologics and Surgical Options
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