Hidradenitis Suppurativa

• Chronic, recurrent inflammatory disease of the hair follicle characterized by nodules, abscesses, draining tunnels, and scarring in intertriginous areas.
• Predominantly affects the axillary, inguinal, genital/perineal, gluteal, and inframammary regions.
• Pathogenesis primarily involves follicular occlusion, followed by follicular rupture and an intense inflammatory response; HS is not primarily a disorder of apocrine gland obstruction.
• Usually begins after puberty, commonly in young adulthood.
• More common in women.
• A family history is present in a substantial subset of patients.
• Strongly associated with smoking and obesity.
• May be associated with metabolic syndrome, severe acne, pilonidal disease, and inflammatory bowel disease.
• Secondary bacterial infection may occur, but HS is not primarily an infectious disease.
• Can have a profound impact on pain, mobility, sexual health, and quality of life.

• Recurrent, painful, deep inflammatory nodules.
• Abscesses may rupture and produce purulent or seropurulent drainage, which may be malodorous.
• Lesions characteristically recur at the same anatomical sites.
• Chronic disease may lead to subcutaneous tunnels (sinus tracts) and permanent scarring.
• Characteristic double-ended or polyporous comedones.
• Pain may be severe or throbbing.
• Diagnosis is supported by the triad of typical lesions + typical distribution + chronicity/recurrence.

• Deep, tender inflammatory nodules.
• Deep abscesses.
• Purulent or seropurulent drainage may be present.
• Subcutaneous tunnels / sinus tracts in chronic disease.
• Double-ended comedones +++, a characteristic finding.
• Nodules may coalesce into indurated plaques or masses.
• Hypertrophic, fibrotic, or bridging scars.
• Advanced disease may cause extensive architectural distortion and functional impairment.

HURLEY CLASSIFICATION

• Stage I: one or more abscesses/inflammatory nodules without tunnels or scarring.
• Stage II: recurrent abscesses with tunnels and scarring, with lesions separated by areas of relatively normal skin.
• Stage III: diffuse or near-diffuse involvement with multiple interconnected tunnels and abscesses throughout an anatomical region.

• Axillae +++.
• Inguinal folds +++.
• Genital and perineal/perianal regions.
• Inframammary folds.
• Buttocks and intergluteal region.
• Inner thighs.
• Disease is often bilateral and recurrent at the same sites.

• Dilated follicular openings and double-ended comedones may be visible.
• Keratotic follicular structures.
• Erythematous background in active inflammatory lesions.
• Nonspecific vascular structures may occur.
• Dermoscopy may provide additional information but is not required for diagnosis, which remains primarily clinical.

• Primarily a clinical diagnosis.
• Based on three key features: characteristic morphology + typical intertriginous distribution + chronic/recurrent course.
• No specific laboratory test is required in typical disease.
• Bacterial cultures are not routinely required and are mainly indicated when secondary infection is suspected.
• Cutaneous ultrasound may help determine the extent of subcutaneous tunnels, particularly when planning procedures.
• Assess relevant comorbidities, including obesity, smoking, metabolic syndrome, depression/anxiety, and inflammatory bowel disease, when appropriate.

• Furuncle / furunculosis.
• Bacterial skin abscess.
• Inflamed or ruptured epidermoid cyst.
• Pilonidal disease.
• Perineal/cutaneous Crohn disease with fistulas.
• Lymphogranuloma venereum.
• Scrofuloderma.
• Actinomycosis.
• Other chronic inflammatory or infectious disorders causing abscesses and sinus tracts.

• Treatment depends on disease severity, inflammatory activity, tunnels/scarring, and impact on quality of life.
• General measures include smoking cessation, weight management when appropriate, minimizing friction, and avoiding tight clothing.
• Appropriate pain management is an important component of care.
• Mild/localized disease: topical clindamycin 1% may be used, particularly for superficial inflammatory lesions.
• Intralesional triamcinolone may be considered for selected acute, painful inflammatory nodules.
• Mild-to-moderate inflammatory disease: oral tetracyclines, commonly doxycycline, may be used for their anti-inflammatory effect.
• Selected patients may require systemic antibiotic combinations such as clindamycin + rifampin under medical supervision.
• Moderate-to-severe disease: biologic therapy may be indicated; TNF or IL-17 inhibitors are among the available options depending on the patient, local guidelines, and treatment availability.
• Hormonal therapies such as spironolactone or combined oral contraceptives may benefit selected female patients.
• Incision and drainage alone provides temporary relief and has a high recurrence rate; it is generally not definitive HS treatment.
• Recurrent nodules or tunnels: deroofing or targeted surgical excision.
• Extensive scarred disease may require wide surgical excision.
• Isotretinoin is not a standard first-line treatment for HS and has inconsistent efficacy; it may have a role in selected acne-associated phenotypes.
• Psychological support and screening for depression/anxiety are important components of comprehensive management.