Systemic antibiotic therapy for acne: a review. 
Acne is a multifactorial disease of the pilosebaceous unit in the skin.  Four contributing pathogenic factors need to be elucidated and include excess sebum production, follicular hyperkeratinization, colonization of the pilosebaceous unit by Propionibacterium acnes, which is a gram positive anaerobic diphtheroid, and the release of inflammatory mediators into the follicle and dermis.  One or more of these factors are targeted by each of the systemic therapies for this disease and its variant, including systemic antibiotic therapies, which will be reviewed here.