Multicentric reticulohistiocytosis masquerading as lepromatous leprosy.

A 23-year old male presented for evaluation of skin coloured, non-scaly, asymptomatic papulonodules of sizes varying from 0.5 cm to 2 cm of 4 years duration distributed all over the body including the ears. The plaques present on the face gave the appearance of a 'leonine facies'. Clinically mistaken for lepromatous leprosy in reaction the patient was treated with antileprosy and anti-inflammatory drugs in 3 other centres for months with no improvement. Systemic involvement included painful swelling of both knee joints, pericardial effusion episcleritis and enlarged liver. Negative slit smears for AFB from the nodules repeatedly and the histology of one on the skin nodules clinched the diagnosis of multicentric reticulohistiocytosis. The case is reported not only for its rarity, and varying clinical lesions simulating lepromatous leprosy but also to alert the leprologists to avert unreasonable delay in diagnosis.