[Acute toxoplasmosis with necrotizing vasculitis (author's transl)].

Acute toxoplasmosis was diagnosed in a Japanese woman aged 31 years after the discovery of a raised lysis titre and agglutinins resistant to 2-ME, as well as early increases in specific IgM followed later by increases in specific IgG. A high fever was present and signs of mainly distal polymyositis. The muscle lesion was confirmed by EMG examination. No increase in muscle enzyme levels was noted at any stage of the disease. Muscle biopsy demonstrated inflammatory lesions in interstitial tissue and perimysium, and, more particularly, segmental necrotizing arteritis in several arterioles. All the arteriolar lesions were at the same stage of development. After prednisolone (60 mg/day) had failed to produce improvement, spiramycin was given and caused apyrexia in 48 hours and definite disappearance of all muscle signs within several days. Recovery was complete and there was no return of symptoms 18 months later. The authors discuss the association of acute toxoplasmosis, polymyositis, and necrotizing vasculitis, and suggest a possible pathogenic role for the immune complexes deposited on the arterial walls.