The predictive value of slit skin smears and skin biopsy in the diagnosis of cutaneous leishmaniasis: Comparative study

Background: Slit skin smears and skin biopsy are the most common techniques used for the diagnosis of cutaneous leishmaniasis (CL) in endemic areas. Aim of work: This study was carried out to compare the predictive value of slit skin smears and skin biopsy in the diagnosis of CL. Patients and Methods: 30 patient were included in the present study with clinically suspected lesions of CL. Their age ranged from 20 to 55 years. The duration of lesions was from one month to six months. Slit skin smears and skin biopsy were done for every patient, and then the results were compared. Results: Among 30 cases, 14 cases (46.6%) showed positive slit skin smears for Leishmania donovani (LD) bodies and 16 cases (53.4 %) showed negative slit skin smears for LD bodies. Histopathological examination of sections obtained from skin biopsies revealed that 7 cases (23.3%) were negative for LD bodies and no granuloma was seen, 23 cases (76.6%) showed features favoring the diagnosis of CL (21 cases had LD bodies and 2 cases had granulomas formed of epitheliod histiocytes, giant cells, lymphocytes and plasma cells). The sensitivity of skin biopsy was significantly higher than slit skin smears (76.6% versus 46.6% P <o.oo1). All lesions with positive result on slit skin smears also showed positive result on skin biopsies. Conclusion: Histological examination of sections obtained by a skin biopsy is the most sensitive and conclusive technique for the diagnosis of CL. Slit skin smears can be used as a first step technique for the diagnosis of CL.