Pityriasis lichenoides and acquired toxoplasmosis

A 32-year-old man was seen in January 1997 for a skin eruption which had ap peared 2 months earlier. He was in good health and was not taking any drugs . He had not left town and denied any other symptom except a short, flu-lik e episode 2 months earlier. On examination, he showed multiple, papular, scaly and necrotic lesions ove r the trunk, arms (Fig. 1), and thighs. The face and the mucosae were spare d. No lymphadenopathy was evident, and the liver and spleen were not palpab le. Routine laboratory tests were insignificant. Histopathology of a papular le sion of the arm showed a thick scaly crust overlying a necrotic epidermis a nd a lichenoid infiltrate of lymphocytes and neutrophils (Fig. 2). Extravas ation of red blood cells and endothelial swelling of the small superficial vessels were also present. A diagnosis of subacute pityriasis lichenoides (PL) was made, and treatment with 500 mg/day azithromycin, 3 days a week for 1 month, was prescribed wi thout any benefit. Enzyme-linked immunosorbent assay (ELISA) for Toxoplasma gondii showed immunoglobulin G (IgG) 150 (n.v. <10) and IgM 1.35 (n.v. <0. 65). Diagnosis of recent toxoplasmosis prompted an ocular examination which excluded any eye involvement. A specific treatment with spiramycin, 3,000.000 U twice a day for 2 months, was given. The patient underwent a complete resolution of skin lesions whi ch healed leaving atrophic and hyperpigmentary signs (Fig. 3). At the end o f therapy, ELISA was still positive for both IgG and IgM. Spiramycin was ch anged to trimethoprim-sulfamethoxazole, 800-160 mg twice a day, which was c ontinued for 2 months. Reactive serology persisted for both IgG and IgM for 8 months, but no new l esions developed.