Leprosy is a chronic infection caused by bacteria called Mycobacterium leprae. This is a prevalent disease in low-income countries, and it has not been completely eradicated. We present the case of a 29-year-old man with a previous diagnosis of Hansen's disease, who consulted for pain in the left elbow and wrist, associated with fever with preserved mobility and pain on palpation. Diagnosis of mononeuropathy of the ulnar nerve was made by MRI of the elbow and forearm. This entity corresponds to an infrequent complication of this infection with few cases reported in the literature. Our added value with this case is to show and explain the clinical imaging correlation, which is vital to understand the presentation of symptoms and to carry out a comprehensive and rapid approach to establish adequate and timely treatment.
Keywords: Leprosy; MRI; erythema nodosum; mononeuropathy; tuberculoid leprosy; type III hypersensitivity reaction; ulnar nerve.