Acne Keloidalis Nuchae

Acne keloidalis nuchae is a chronic scarring folliculitis of the posterior neck and occipital scalp, forming firm papules, pustules and keloid like plaques. It affects mainly men of African descent in the second to fourth decades.

Risk factors: close shaving or cutting hair, curved hair follicles, friction from collars, helmets and headgear, androgens, obesity, trauma, medications (ciclosporin, phenytoin).

Pathology is inflammation and fibrosis around ingrown, damaged hair follicles.

Itchy, tender papules and pustules at the nape of the neck and occipital scalp that coalesce into firm keloidal plaques with hair loss, tufting and sinus tracts.

• Chronic course with exacerbations; scarring alopecia.
• Differential diagnosis: folliculitis decalvans, pseudofolliculitis barbae, keloid, dissecting cellulitis of the scalp, acne vulgaris, tinea capitis, hidradenitis suppurativa, sarcoidosis, secondary syphilis.
• Complications: permanent hair loss, disfiguring keloid, secondary bacterial infection, abscess and sinus formation, pain, psychosocial distress.

Clinical.

• Swab culture and KOH to exclude infection and tinea capitis.
• Biopsy for atypical, resistant or ulcerated lesions.
• Glucose and lipids when long term retinoids or steroids are planned.

Early treatment prevents scarring; late disease needs procedural therapy.

• Supportive: avoid close shaving and cutting of hair (keep hair at least 1 to 2 mm long), avoid friction from collars and headgear, wash gently, avoid hair products that clog follicles, weight loss.
• Pharmacological: clobetasol propionate 0.05 percent or betamethasone dipropionate 0.05 percent twice daily for 4 to 6 weeks, then taper; clindamycin 1 percent lotion twice daily; tretinoin 0.025 percent cream at night; benzoyl peroxide 5 percent wash. Intralesional triamcinolone acetonide 10 mg/mL into papules and plaques every 4 to 6 weeks (maximum 20 mg per session, up to 40 mg for large plaques). Oral doxycycline 100 mg twice daily for 3 to 6 months for inflammatory disease. Isotretinoin 0.5 mg/kg daily for 4 to 6 months for refractory disease under specialist care.
• Procedures: surgical excision with healing by secondary intention for large keloidal plaques, cryotherapy, laser hair removal (Nd:YAG), intralesional 5 fluorouracil in resistant keloids.
• Special groups: pregnancy, topical clindamycin and avoid doxycycline, tretinoin and isotretinoin; women are rarely affected; if affected, assess for hyperandrogenism; children, avoid shaving and use topical treatment.
• Red flags: pus and abscess formation, rapid enlargement, sinus tracts, ulceration, extensive scarring, suspicion of malignancy, severe pain.
• Follow-up: review every 4 to 8 weeks; sustained hair growth management; refer for surgery when plaques are fixed and disfiguring.