A Six Year Old Boy with Lepromatous Leprosy: A Case Report Revealing an Unsolved Mystery

Leprosy is a chronic granulomatous disease resulting from infection with the unculturable pathogen Mycobacterium leprae. Lepromatous leprosy is the most severe form, typically seen in adults with poor immune response to the bacillus. It is exceptionally rare in young children, specially under 10 years of age due to disease's long incubation period and lower exposure. Early presentation in a child raises question about atypical transmission and host susceptibility. We report a case of a six-year-old boy from Purbadhola, Netrokona, Bangladesh with a four-year history of progressive, asymptomatic erythematous plaques on the left arm and right side of the face. Physical examination revealed well-defined, dry plaques without definitive sensory loss or nerve thickening. Initial differential diagnoses included lupus vulgaris, lepromatous leprosy, and sarcoidosis. Slit skin smear revealed a bacillary index of 1+, suggesting lepromatous leprosy and again we went for skin biopsy for histopathology for any additive diagnosis and it revealed tuberculoid leprosy. The patient was treated with WHO-recommended multibacillary multidrug therapy (rifampicin, dapsone, clofazimine) in collaboration with Damien Foundation. After 4 months, there was marked improvement, with near-complete resolution of skin lesions. This case highlights the diagnostic complexity in pediatric leprosy where clinical, histopathological, and bacteriological findings may not align. It underscores the importance of comprehensive evaluation and the role of slit skin smear in all suspected cases of leprosy especially in children. Early diagnosis and appropriate treatment are crucial to prevent long-term complications and transmission.