Producation of large amounts of sebum by the sebaceous glands, particularly on the forehead, nose, chin, shoulders and back, during puberty. The excess builds around the hair shaft, hardens, and blocks the follicle. The blocked secretions elevate the skin and form a reddish papule.
As bacteria feed on teh subum, they release irritating substances that produce inflammation.
In severe cystic acne, the papules enlarge to form deep, pus-filled cysts.
Treatment: topical cleansing drugs, topical or oral antibiotic drugs to kill skin bacteria, oral vitamin A-type drugs for severe cystc acne