Allescheria boydii infections in the immunosuppressed host.

Allescheria boydii, a true fungus frequently isolated from soil, is best known as a causative agent of maduromycosis of the foot. In our report we describe two patients under treatment for acute leukemia who died from rapidly progressive A. boydii infections. One patient had signs of central nervous system infection and was found at autopsy to have had a large brain abscess. The second patient had a cavitary necrotizing pneumonia with thoracic inlet obstruction (Pancoast's syndrome) and failed to show improvement despite treatment with amphotericin B. The clinical spectrum of allescheriasis is reviewed with particular emphasis on its role as a pathogen in the compromised host. Since A. boydii may resemble other fungi morphologically in tissue sections and may produce infections clinically similar to other mycoses, culture of the organism is required for definitive diagnosis. Based on recently reported in vitro susceptibility studies, miconazole may have a future role in the therapy of A. boydii infections which are resistant to presently available antifungal agents.