Chemotherapy-induced erythema nodosum leprosum: successful treatment with thalidomide

The severity and outcome of a chronic granulomatous infection caused by M. leprae depend on the cell-mediated immunity towards the pathogen. The disea se classification is based on the host's response to M. leprae ranging from high to low resistance (polar tuberculoid leprosy to polar lepromatous lep rosy). The host's position in the spectrum is not stable; leprosy reactions reflecting changed immune status may occur spontaneously or during chemoth erapy. The type II reaction or erythema nodosum leprosum can most often be seen in patients with lepromatous leprosy, a multiorgan disease characteriz ed by an unrestricted bacillary replication. Clinically, this reaction is c haracterized by crops of painful bright pink, dermal and subcutaneous nodul es arising in clinically normal skin, in association with fever, malaise, g lomerulonephritis and arthralgias. Therefore, prompt institution of immunos uppressive therapy with corticosteroids or thalidomide is recommended. This case report describes the development of erythema nodosum leprosum during chemotherapy treated successfully with thalidomide. Furthermore, immunologi c effects and potential side effects of this drug are discussed.