A common skin condition starting after puberty, and which may persist for many years. It involves plugged pores (blackheads and whiteheads), pimples and deeper nodules on the face, neck, trunk and even the upper arms. It arises from pilosebaceous glands (relating to hair follicles and associated SEBACEOUS GLANDS). SEBUM production is increased and bacterial proliferation causes inﬂammation with PAPULE and PUSTULE formation. Plugs of sebum and epidermal cells form blackheads (comedones); the colour is not due to dirt but to dried oil and shed skin cells in the hair-follicle openings.
Treatment Twice-daily washing with a salicylic-acid cleanser can help remove the pore-blocking debris, as can daily shampooing. Use only oil-free cosmetics and hide blackheads with a ﬂesh-tinted acne lotion containing benzoyl peroxide, acid or sulphur. Never squeeze blackheads, however tempting; ask a skin specialist how to do this properly. Other treatments include microdermabrasion, and the antibiotic lotions erythromycin and clindamycin may be eﬀective. Tretinoin and adapilene can be used on the skin but are not permitted in pregnancy and may cause problems such as hypersensitivity to sunlight, so medical advice is essential. In resistant cases, long-term suppressive oral therapy with one of the TETRACYCLINES or with ERYTHROMYCIN may be necessary. In females a combined oestrogenantiandrogen ‘pill’ is an alternative. Severe resistant acne can be cleared by a 16- to 24week course of oral isotretinoin, but this drug is teratogenic (see TERATOGENESIS) and can cause many side-eﬀects including depression, so its use requires specialist supervision.