Hair Foundation
HAIR DISEASE » Hair Injury (Scarring Alopecia)
Folliculitis Keloidalis Nuchae

Inflamed hair follicles progress to acne-like lesions and eventual formation of the lumpy scars called keloids. Incidence is higher in people of African ancestry, who also have a genetic predisposition to form keloidal scars after injury. The lesions of folliculitis keloidalis nuchae occur frequently on the back of the neck just below the hairline, but also can involve the scalp. Cause of the condition is unknown.

From article:
Hair Loss and Its Causes