Tetracycline for the treatment of pityriasis lichenoides

Abstract

Thirteen cases of pityriasis lichenoides were treated with oral tetracycline. Five of them were completely cured, another seven had to continue to take 1 g/day. Addition of an antihistamine in one patient who did not respond to tetracycline gave a dramatic result. Throat swab cultures yielded coagulase positive staphylococci in four cases and other kinds of bacteria in many other cases. Based on the results of the treatment and histological findings, it is postulated that the pathogenesis of pityriasis lichenoides may be due to a hypersensitivity reaction to infectious agents.