Challenging in leprosy relapse with antiphospholipid syndrome diagnosis: A case report.

Key Clinical Message: Infectious diseases like leprosy can cause antiphospholipid antibodies, leading to blood clots. Clinicians should consider this for patients with unusual thrombotic events and prior infectious disease history. Abstract: This case report details the diagnostic challenge of a 42-year-old man with a history of treated leprosy who presented with clinical features suggestive of antiphospholipid syndrome (APS). Vascular angiography revealed thrombosis, and serological tests were positive for APS antibodies. However, the patient subsequently developed symptoms, including thenar atrophy, paresthesia, and hypopigmented skin patches, which prompted further investigation. Electromyography detected sensorimotor polyneuropathy, while a nerve biopsy indicated a resurgence or chronic presence of leprosy. Despite initial APS management, the case evolved into a leprosy relapse confirmation after 20 years of remission, underscoring the diagnostic intricacies when concurrent autoimmune antibodies and infectious disease manifestations are present. This report emphasizes the importance of considering a broad differential diagnosis, including the potential for infectious disease relapse, in the presence of antiphospholipid antibodies. It illustrates the necessity of an interdisciplinary treatment approach in complex clinical scenarios.