Fatal arteritis due to Pythium insidiosum infection in patients with thalassaemia.

Six thalassaemic patients had a distinct clinical syndrome characterized by progressive ischemia of the lower extremities, with ascending arteritis and thrombosis of the main arteries of the lower limbs. With periodic acid Schiff and Gomori's methenamine silver staining a large number of hyphae were revealed in the arterial wall and the outer part of the thrombus. Pythium insidiosum was isolated from 3 patients. The clinical course of the disease was progressive gangrene of the extremities and the patients invariably died when the infectious process reached the bifurcation of the aorta. There is no effective antimicrobial agent for the syndrome and radical amputation was the only method to ensure survival of the patients. P. insidiosum infection should be considered in thalassaemic patients with leg ulcers or arterial occlusion of the lower limbs.