Pityriasis lichenoides-like exanthem and primary infection by Epstein-Barrvirus

A 43-year-old man with a history of recurrent herpes simplex, and without a history of atopy, presented with a sudden appearance of an exanthem 10 day s before presenting to the clinic. The exanthem affected the face, flexural areas, hands, and feet. No local symptomatology and no systemic involvemen t were observed. The exploration revealed a polymorphous exanthem formed by maculopapular le sions, umbilicated vesicles, crusts, and purpuric and necrotic elements, wi th a pattern of acute pityriasis lichenoides (Figs 1 and 2). The histopathologic examination of a skin biopsy specimen showed a dense ly mphohistiocytic infiltrate, with a linear disposition over the entire thick ness of the papillary dermis and in the upper part of the reticular dermis. At the dermoepidermal junction, vacuolar alteration of the basal layer was observed, with the presence of mononuclear exocytosis, edema extending to the papillary dermis, and extravasated red cells. Spongiosis, keratinocytic focal necrosis, and parakeratosis were observed in the epidermis (Fig. 3). Analytical explorations revealed lymphocytosis and slight elevation of tran saminases. Serologies to hepatitis A virus, hepatitis B virus, hepatitis C virus, cytomegalovirus, human immunodeficiency virus (HIV) 1 and 2, syphili s, and human parvovirus B19 were negative. The CD4 and CD8 lymphocyte count s were normal. The serology to Epstein-Barr virus (EBV) (Table 1) was consi stent with a primary infection by EBV. Oral acyclovir treatment, 1 g daily for 7 days, was started and the exanthem disappeared in 7 days.