Publication:

Slit skin smear or Fite-Faraco staining of tissue sample, which is a better indicator of bacillary load?

Background Leprosy is clinically diagnosed on the basis of presence of following cardinal signs: 1. Hypopigmented or erythematous anesthetic patch on skin, 2. Thickened and/or tender peripheral/cutaneous nerve, 3. Acid fast bacilli in slit skin smear. This study aims at comparing bacillary indices in slit skin smears with that from biopsy samples.

Methods After obtaining informed written consent, slit skin smears were performed and observed for acid fast bacilli. Punch biopsies of lesions were taken and processed and stained with Fite-Faraco technique. The presence or absence of acid-fast bacilli in both modalities was noted.

Results Slit skin smears were positive in 24 patients and negative in the rest. And 26 patient’s biopsy reports had Fite-Faraco positivity, out of the total 46 patients. The p=0.67 which was not significant at significance value 0.05.

Conclusions Skin smear is an equally reliable indicator of bacillary load as Fite-Faraco bacillary index in tissue.