Clinico-Histopathological Correlation in Leprosy: A Cross-Sectional Study of Ridley-Jopling Concordance At A Tertiary Care Centre

Abstract

Leprosy is placed along the Ridley-Jopling spectrum using clinical, histopathological and bacteriological criteria, and agreement between clinical and histopathological typing guides treatment and case detection. Thirty consecutive untreated patients attending a tertiary care dermatology outpatient department were typed clinically and by skin biopsy, and slit-skin smears provided the bacteriological index. Patients were aged 10 to 70 years, and 53% were 21 to 40 years old, with a male-to-female ratio of 1.7:1. Borderline tuberculoid was the commonest type both clinically and histopathologically. Anaesthesia and hypopigmented patches were the leading clinical features, and the bacteriological index was positive in half the patients. Exact clinico-histopathological agreement was 70% (Cohen’s kappa 0.59), complete for lepromatous disease and lowest for the mid-borderline and borderline lepromatous groups. Grouped into paucibacillary and multibacillary categories, agreement rose to 94.1% and 76.9% (kappa 0.72). Clinical and histopathological typing agree in most cases but diverge across the immunologically unstable borderline spectrum. Combining clinical examination, histopathology and bacteriological index classifies leprosy most reliably and lowers the risk of undertreating an infectious patient.