THE CLINICAL AND IMMUNOLOGICAL SPECTRUM OF AMERICAN CUTANEOUS LEISHMANIASIS

American cutaneous leishmaniasis is characterized by a spectrum of cli nical manifestations. These include localized, often self-healing sing le lesions, intermediate forms which frequently produce mucosal lesion s and often show exaggerated delayed-type hypersensitivity (DTH), and the rare diffuse cutaneous leishmaniasis in which no reaction of prote ctive cell-mediated immunity or DTH can be demonstrated. Clinical, pat hological and immunological studies have begun to unravel some of the mechanisms associated with different disease manifestations, dependent on complex interactions between the host immune response, measured in terms of indices including lymphocyte subsets and lymphokines in vitr o and within active lesions, and different species of Leishmania.