De novo Histoid Leprosy of face mimicking Lupus Miliaris Disseminatus Faciei: An uncommon presentation

Abstract

Background: Background: Histoid leprosy is a rare variant of lepromatous leprosy with distinct clinical features and characteristic histopathology. It is diagnosed using classical histopathological findings and Fite staining, distinguishing it from dermatofibroma and neurofibroma using factor XIIIa and S100 on immunohistochemistry. A middle-aged female presented with facial lesions mimicking Lupus Miliaris Disseminatus Faciei (LMDF). Case report: A 35-year-old female with facial lesions for two months, previously treated with oral isotretinoin for acne vulgaris, presented with multiple papules. Differential diagnoses included lupus miliaris disseminatus faciei (LMDF), multiple trichoepitheliomas, sarcoidosis, and post kala azar dermal leishmaniasis (PKDL). A slit skin smear examination revealed numerous acid fast bacilli, longer than normal lepra bacilli, and tapering ends. A punch biopsy revealed a grenz zone, an atrophic epidermis, sheets of elongated epithelioid cells with histoid habitus, and an inflammatory infiltrate in the dermis. A Fite stain was positive, confirming histoid leprosy. Multidrug treatment was initiated with rifampicin, clofazimine, and dapsone. LMDF is a rare dermatoses with asymptomatic papular eruptions over the face around the eyelids and epitheloid granuloma with caseous necrosis in the dermis. Conclusion: Several atypical presentations of histoid leprosy have already been described like Erythema nodosum like and figurate lesions. But LMDF like lesions is a rare presentation and it should be added to various morphological presentations of histoid leprosy.