Mucocutaneous leishmaniasis caused by Leishmania donovani infection in an Indian man.

BACKGROUND

Leishmaniasis is a protozoal disease caused by species of Leishmania. Mucocutaneous leishmaniasis (MCL) involves the skin and mucosa. India is endemic for species such as Leishmania donovani and Leishmania major, which are responsible for visceral and cutaneous leishmaniasis, respectively. Although MCL has been reported from India previously, the implicated pathogen was identified as L. donovani in only one case.

CASE REPORT: A 55-year-old man presented with a nasal ulcer of four years' duration. He had been treated for borderline lepromatous (BL) leprosy 25 years earlier. Differential diagnoses of MCL, lupus vulgaris, and subcutaneous mycosis were considered. Leishman-Donovan bodies were seen on tissue imprints, and histopathology showed epidermal thinning with loss of appendages and dense pandermal infiltrate. Polymerase chain reaction was positive for L. donovani-specific DNA amplification. A diagnosis of MCL with treated BL leprosy was made. The patient was treated with sodium stibogluconate and achieved complete healing of the ulcer.

CONCLUSIONS

The coexistence of manifestations of disease from opposite ends of the spectrum (a hyperergic form of leishmaniasis with an anergic form of leprosy) is difficult to explain. However, the development of MCL after the cure of BL leprosy may reflect the loss of the inhibitory effect of Mycobacterium leprae antigen on interferon-γ production, and delayed persistence and the gradual clearance of the antigen from the body may account for the 20-year time lag. Further research centered on the immunological interactions between leishmaniasis and leprosy is warranted, particularly with respect to different Leishmania species.