Systematic review of the efficacies and adverse effects of treatments for pityriasis lichenoides.

The current literature consists almost entirely of uncontrolled studies, and none provides compelling data to support an evidence-based approach to PL treatment. Pityriasis lichenoides chronica and pityriasis lichenoides et varioliformis acuta should be distinguished in response to treatment, and definitions of response to treatment must be standardized. Additional randomized control studies with longer follow-up will help better differentiate between treatment efficacies and adverse effects.