What is acne necrotica miliaris?

This chronic folliculitis of the scalp, which primarily affects middle-aged men, presents as follicular-based pustules that quickly develop into perifollicular crusts and scale. The eruption may be asymptomatic or pruritic. If the lesions are pruritic, secondary excoriations may predominate. Acne necrotica miliaris does not result in permanent scarring or hair loss. Most patients respond to low-dose tetracycline, which may need to be continued for years.