Unusually extensive disease caused by Leishmania major parasites.

Simple cutaneous leishmaniasis (CL), which is endemic in several areas of Israel, is usually caused by Leishmania major. CL, which is caused by replication of parasites within dermal macrophages, is self-limited and almost always confined to the skin. We recently encountered two cases of CL in which skin defenses were breached and lesions appeared in subcutaneous locations. In one case, abnormal cell-mediated immune function was detected. The purpose of this article is to present these data and to comment on the immunological aspects of leishmaniasis.