Borderline tuberculoid leprosy mimicking sarcoidosis: A case report

INTRODUCTION: Leprosy is a chronic infectious granulomas disease caused by Mycobacterium leprae that can manifest as a wide variety of immunological and clinical features. CASE SUMMARY: Here, we describe the case of a woman with clinical characteristics of borderline tuberculoid (BT) leprosy that manifested as 3 asymmetric skin lesions involving her hip and lower limbs. This unusual presentation was initially misdiagnosed as sarcoidosis because noncaseating granulomas are a histopathological feature of both diseases. Differentiation and the diagnosis of BT leprosy was achieved using real-time polymerase chain reaction (PCR) to amplify an M leprae specific DNA sequence and to detect serum antibodies specific to M leprae antigens. Accordingly, a 6-month course of multidrug therapy led to a marked improvement in the skin lesions. CONCLUSION: The use of auxiliary tests including real-time PCR to amplify an M leprae-specific DNA sequence, enzyme-linked immunosorbent assay, and dipstick detection of serum antibodies specific to M leprae antigens are good methods to obtain a correct diagnosis of BT leprosy.