Infectious causes of pityriasis lichenoides: a case of fulminant infectious mononucleosis.

Pityriasis lichenoides is a rare cutaneous eruption of unknown cause that spans a spectrum of clinical severity. Infectious agents have long been suspected as etiologic factors. The present case is the first to demonstrate a known EBV-mediated process evolving and resolving in concert with pityriasis lichenoides. Epstein-Barr virus, Toxoplasma gondii, and HIV are the most frequently reported infectious triggers of pityriasis lichenoides. Pityriasis lichenoides may arise secondary to EBV-mediated acute infectious mononucleosis.