Pityriasis Lichenoides

Abstract

Pityriasis lichenoides (PL) is a term used to define a disease spectrum encompassing two main variants, pityriasis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica (PLC). Early PLEVA lesions are small, asymptomatic, erythematous macules turning into pinkish papules, which may centrally become vesiculopustular, hemorrhagic, necrotic, ulcerated, and/or crusted before spontaneously regressing in a few weeks. PLC classically presents with small, asymptomatic, firm, erythematous papules developing a reddish-brown hue and a centrally adherent mica-like scale. Dermatoscopy of PLEVA shows a central whitish area or a crust having an amorphous brownish appearance, both surrounded by a well-defined ring of pinpoint and/or linear vessels with a targetoid aspect. Orange-yellowish structureless areas and nondotted vessels (including milky-red areas/globules, linear irregular and/or branching vessels) are the most frequent dermatoscopic characteristics of PLC active lesions.