A study of histopathology of clinically normal appearing skin in the tuberculoid spectrum of leprosy.

Histological changes suggestive of leprosy in clinically normal skin have been well documented in the lepromatous spectrum and rarely in the tuberculoid spectrum of the disease. This study attempts to evaluate the histology of clinically normal appearing skin in cases of borderline tuberculoid and tuberculoid leprosy. Biopsies from lesional and a clinically normal appearing skin from newly diagnosed patients with BT or TT leprosy seen in the outpatient department over a period of one year were evaluated by a blinded pathologist. Sixty five patients were included in the study. Six patients had granulomas in the normal skin, six others showed a histological pattern consistent with indeterminate leprosy in the biopsies taken from normal skin. The clinicians must be aware that a small percentage of cases in the TT spectrum also have involvement of normal appearing skin. These patients are at a high risk of under-treatment and may be a cause for paucibacillary relapse. This is a pilot study and a larger sample size is recommended to evaluate the real scenario.