Comparison of leishmanin skin test and direct smear for the diagnosis of cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) is an endemic disease in some parts of Iran and it has high morbidity in some areas of the country. The disease is detected by parasitological examinations including direct microscopic and culture tests. This comparative study aimed to evaluate the relationship between positivity of the leishmanin skin test (LST), microscopically examination and clinical forms of CL for the diagnosis of human cutaneous leishmaniasis. This study was performed on 66 patients suspected to cutaneous leishmaniasis. CL cases evaluated by both microscopical examination and leishmanin skin test. In this study, 1 ml of leishmanin fluid (lot no 121/1, produced in Pasteur institute of Iran) was injected intradermally in forearms of all patients and indurations were measured after 72 hours. Induration of 5 mm and higher was considered as positive results. The collected data were statistically analyzed using the SPSS version 13.5. From 66 CL patients who were evaluated in this study, 30 (45.5%) of them had positive microscopically results while 28(42/4%) of them had showed positive leishmanin skin test (≥ 5 mm diameter). From 36 (54.5%) patients who had negative microscopical examination, only 6(16/6%) of them had positive leishmanin skin test. The agreement between two tests was 87.9 % by kappa analysis (p< 0.01). In attention to the results of this study, it seems the LST would be used as an alternative diagnosis method when there is a strong clinical doubt to cutaneous leishmaniasis even there is no parasite in direct smear.