[Hansen's Disease: An Unusual Manifestation of an Ancient Disease].

Hansen's disease, commonly known as leprosy, is an infectious disease caused by Mycobacterium leprae. Being rare in developed countries, it is an increasingly common imported disease due to the migratory flow from countries where it is endemic. We present the case of a 21-year-old man who went to the emergency department with complaints of additive polyarthralgia involving large joints, papules, and erythematous plaques on the limbs with bullae and central necrosis and fever with chills for one week. Skin biopsy was performed revealing neutrophilic infiltrate with perineural granulomas. The bacilloscopy detected acid-alcohol resistant bacilli. The diagnosis of multibacillary HD with type 2 lepromatous reaction (erythema nodosum leprosum - ENL) was established, showing clinical improvement under corticosteroid therapy. ENL usually presents with painful lesions, being an atypical presentation of leprosy, especially in the presence of bullae and necrosis, making diagnosis difficult and challenging. Social stigma is often present making it difficult to accept the disease as well as adherence to treatment.