Hormonal factors, particularly androgens, appear to be important in the pathogenesis of acne vulgaris. The sebaceous glands in acne are more sensitive to normal blood levels of androgens, and are stimulated to produce more sebum. Corynebacterium acnes in the sebaceous follicles act on triglycerides in the sebum to form free fatty acids which might alter the process of keratinization in the follicular canal. A microcomedo is formed which can progress to the clinical lesions of acne. Sebum and its components may also be inflammatory if released into the skin. There are, however, still a number of unanswered questions relating to acne pathogenesis. Currently, therapy of acne vulgaris revolves around topical benzoyl peroxide and retinoic acid and systemic tetracyclines. Benzoyl peroxide and tetracyclines are antibacterial while retinoic acid is comedolytic. Because of these different actions, combined therapy appears to be more effective (benzoyl peroxide and/or tetracyclines together with retinoic acid). Topical antibiotics show promise as new therapeutic agents.