Case for diagnosis. Infiltrated areas on the trunk.

Leprosy is an infectious disease with chronic evolution, caused by Mycobacterium leprae, an acid-fast bacillus that mainly affects the skin and peripheral nervous tissue. Many of the clinical manifestations of leprosy can mimic connective tissue diseases. The authors present the case of a 49-year-old woman who had been treated for four years for systemic lupus erythematosus in a rheumatological service. Skin biopsy of a plaque on the inguinal region was compatible with borderline lepromatous leprosy associated with a type 1 lepra reaction. The patient is undergoing treatment with multibacillary multidrug therapy, showing clinical improvement.