Topical glyceryl trinitrate: a possible treatment for cutaneous leishmaniasis.

The treatment of cutaneous leishmaniasis (CL) is difficult in both the old and new worlds. However, nitric oxide (NO) is involved in host cell mediated immune responses against intracellular parasites such as Leishmania major, and both in vitro and in vivo immunological studies indicate that Leishmania parasite killing by macrophages is mediated by this substance. Glyceryl trinitrate (GTN) is an exogenous NO donor; we have successfully treated a young man with cutaneous leishmaniasis with topical GTN. We believe this to be the first reported use of GTN in the treatment of human CL.