Pityriasis lichenoides and acquired toxoplasmosis
Rongioletti, F.; Delmonte, S.; Rebora, A.
International Journal of Dermatology 38(5): 372-374
1999
ISSN/ISBN: 0011-9059 PMID: 10369549 Document Number: 500755
A 32-year-old man was seen in January 1997 for a skin eruption which had appeared 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-like episode 2 months earlier. On examination, he showed multiple, papular, scaly and necrotic lesions over the trunk, arms (Fig. 1), and thighs. The face and the mucosae were spared. No lymphadenopathy was evident, and the liver and spleen were not palpable. Routine laboratory tests were insignificant. Histopathology of a papular lesion of the arm showed a thick scaly crust overlying a necrotic epidermis and a lichenoid infiltrate of lymphocytes and neutrophils (Fig. 2). Extravasation 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 without 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 which healed leaving atrophic and hyperpigmentary signs (Fig. 3). At the end of therapy, ELISA was still positive for both IgG and IgM. Spiramycin was changed to trimethoprim-sulfamethoxazole, 800-160 mg twice a day, which was continued for 2 months. Reactive serology persisted for both IgG and IgM for 8 months, but no new lesions developed.