Dissecting cellulitis of the scalp

Dissecting cellulitis of the scalp is an uncommon but important cause of scarring alopecia. It can cause tender lumps, pustules, draining sinuses and areas of permanent hair loss, often on the crown or back of the scalp. It belongs to the follicular occlusion spectrum and may occur with acne conglobata, hidradenitis suppurativa or pilonidal disease. Early recognition matters because ongoing inflammation can destroy follicles. Treatment may include antibiotics, isotretinoin, steroids, biologics or surgery in selected cases.