The treatment of acne with antibiotics

When broad-spectrum antibiotics were first introduced two decades ago for the treatment of acne, justification for such therapy seemed reasonably straightforward, e.g., the suppression of the suppurative inflammatory lesions commonly encountered in acne. As time went on, however, certain observations raised questions concerning the rationale for this form of treatment. First, it became apparent with cumulative clinical experience that the disease could ordinarily be controlled by doses of antibiotics lower than those required to treat bacterial infections. Second, bacteriologic studies disclosed that the only bacteria regularly recoverable from acne lesions were the anaerobic diphtheroid Corynebacterium acnes and aerobic coagulase-negative cocci, predominantly staphylococcus type II; both of these bacteria are known to be normal resident skin organisms.1 Thus, as no reports of controlled studies were then available for assessing the true efficacy of antibiotics used in the treatment of acne, the uneasy suspicion arose that such therapy might be inducing a primarily placebo response. In 1965, Freinkel and her collaborators2 demonstrated that the oral administration of tetracycline, even in doses as small as 250 mg daily, resulted in a significant reduction of the free fatty acid concentration of the lipid (sebum) secreted to the skin surface by the sebaceous glands. This effect could be observed in normal subjects as well as in patients with acne and was entirely reversible on discontinuance of drug. The inflammatory lesions of acne are known to result from disorganization of the follicular epithelium, with consequent liberation of the intrafollicular contents, containing sebum, into the dermis.3