BASICS
Description
- Chronic inflammatory skin disease with recurrent nodules, abscesses, sinus tracts, complex scarring.
- Lesions tender, malodorous, often exudative.
- Common sites: axillae, groin, perianal, perineal, inframammary.
- Also impacts psychosocial health.
Epidemiology
- Female > male (3:1).
- More common in African Americans.
- Peak onset: 2nd-3rd decades; range puberty to 40 years.
- Prevalence: 1-4%.
Etiology and Pathophysiology
- Likely follicular epithelium defect, not purely apocrine gland disorder.
- Hormonally driven keratinocyte proliferation → follicular occlusion.
- Mechanical stress → follicular rupture → immune response.
- Secondary bacterial infection.
- Sinus tracts from rupture and reepithelialization.
- Genetics: familial cases suggest autosomal dominant or polygenic.
- ~40% have family history.
Risk Factors
- Obesity
- Smoking
- Hyperandrogenism
- Lithium use may trigger/exacerbate
General Prevention
- Weight loss
- Smoking cessation
- Avoid tight/synthetic clothes, friction, heat, sweating, shaving, deodorants
- Use antiseptic soaps
Commonly Associated Conditions
- Acne vulgaris, acne conglobate
- Dissecting cellulitis of scalp
- Pilonidal disease
- Metabolic syndrome/obesity
- PCOS, androgen dysfunction
- Thyroid disease
- Seronegative arthritis/spondyloarthritis
- IBD
- Squamous cell carcinoma (risk in chronic HS)
- PAPASH syndrome
- Type 2 diabetes mellitus
DIAGNOSIS
History
- Diagnostic criteria (2nd Int. Conference 2009): morphology, location, chronicity.
- Lesions: painful nodules, abscesses, draining sinus tracts, bridged scars, “tombstone” pseudocomedones.
- Location: axillae, groin, perianal/perineal, buttocks, infra/intermammary folds.
- Chronic relapsing course, often refractory.
Physical Exam
- Tender dome-shaped nodules 0.5–3.0 cm.
- Lesions correspond with apocrine-related areas.
- Hurley staging:
- I: Nodules/abscesses without sinus tracts/scarring
- II: Multiple lesions with widely spaced tracts/scars
- III: Diffuse, interconnected tracts/abscesses/scarring
- Sartorius scoring and other tools assess severity and treatment response.
- Lesions often fluctuant with possible malodorous discharge.
Differential Diagnosis
- Acne vulgaris/conglobate
- Furunculosis/carbuncles
- Bartholin/sebaceous cyst infections
- Lymphadenopathy/lymphadenitis
- Langerhans cell histiocytosis
- Actinomycosis
- Granuloma inguinale
- Lymphogranuloma venereum
- Apocrine nevus
- Crohn disease with fistulae
- Fox-Fordyce disease
Diagnostic Tests
- Cultures often negative; if positive, polymicrobial (S. aureus, S. epidermidis)
- Labs: ESR, leukocytosis, anemia, iron studies, serum electrophoresis changes.
- Biopsy for SCC suspicion.
- Hormonal evaluation if female with obesity/hirsutism.
- Ultrasound for sinus tract extent.
TREATMENT
General Measures
- Education, psychosocial support.
- Hygiene: gentle cleansing, avoid shearing stress.
- Avoid dairy, high glycemic load diet.
- Smoking cessation and weight loss essential.
- Symptomatic pain control.
- Warm compresses, sitz baths, topical antiseptics.
Medications
First Line
- Stage I: topical/systemic antibiotics; chlorhexidine cleansers.
- Topical clindamycin 0.1% BID for 12 weeks.
- Systemic tetracyclines (e.g., doxycycline 100 mg BID) for 12 weeks.
- Dapsone 50-150 mg daily (less effective in Hurley III).
- Intralesional corticosteroids (triamcinolone acetonide 10 mg/mL).
- Stage II/III: consider early dermatology referral.
- Biologics: Adalimumab 40 mg weekly approved; TNF-α inhibitors improve severity/quality of life.
Second Line
- Clindamycin + rifampin combination.
- Hormonal agents (mixed evidence).
- Retinoids (second/third line).
- Immunosuppressants (methotrexate, azathioprine, colchicine, cyclosporine).
- Short/long-term corticosteroids.
- IV ertapenem (6 weeks) as bridge to surgery (resistance and cost limits).
Surgery
- Indicated for tunnel/scar removal, refractory disease.
- Wide excision preferred for cure.
- Laser therapy, cryotherapy, photodynamic therapy not routinely recommended.
ONGOING CARE
- Monthly follow-up for symptom and treatment evaluation.
- Diet: avoid dairy and high glycemic foods.
- Zinc supplementation may help.
PATIENT EDUCATION
- Chronic, relapsing disease with variable severity.
- Medications are mostly temporizing.
- Surgery offers best chance for cure in severe disease.
- Smoking cessation and weight loss improve outcomes.
- Psychosocial impact significant.
PROGNOSIS
- Lesions heal slowly (10-30 days).
- Recurrences over years.
- Severe disease causes progressive scarring and sinus tracts.
- Radical wide excision best chance for cure.
- Increased all-cause mortality.
COMPLICATIONS
- Skin contracture and stricturing.
- Lymphatic obstruction, lymphedema.
- Psychosocial: anxiety, depression, self-injury.
- Anemia, amyloidosis, hypoproteinemia.
- Epidural abscess, sacral osteomyelitis.
- Squamous cell carcinoma in chronic tracts.
- Disseminated infection or sepsis (rare).
- Urethral, rectal, bladder fistulas (rare).
REFERENCES
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Seyed Jafari SM, Hunger RE, Schlapbach C. Hidradenitis suppurativa: current understanding of pathogenic mechanisms and suggestion for treatment algorithm. Front Med (Lausanne). 2020;7:68.
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Saunte DML, Jemec GBE. Hidradenitis suppurativa: advances in diagnosis and treatment. JAMA. 2017;318(20):2019-2032.
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Lim SYD, Oon HH. Systematic review of immunomodulatory therapies for hidradenitis suppurativa. Biologics. 2019;13:53-78.
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Alikhan A, Lynch PJ, Eisen DB. Hidradenitis suppurativa: a comprehensive review. J Am Acad Dermatol. 2009;60(4):539-563.
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Wang SC, Wang SC, Sibbald RG. Hidradenitis suppurativa: a frequently missed diagnosis, part 1: a review of pathogenesis, associations, and clinical features. Adv Skin Wound Care. 2015;28(7):325-334.
Additional Reading: - Jemec GBE. Clinical practice. Hidradenitis suppurativa. N Engl J Med. 2012;366(2):158-164.