Leishmaniasis With Disseminated Cutaneous-Mucosal Involvement in a Patient Without Classic Immunosuppression: A Diagnostic Challenge

Disseminated forms of tegumentary leishmaniasis are rare and are usually associated with immunosuppression. Extensive cutaneous-mucosal disease in individuals without evident immunodeficiency represents a diagnostic and therapeutic challenge, and recognizing atypical presentations is important, especially in endemic areas. A 56-year-old male farm worker, born in Santa Tereza do Tocantins and living in a rural area, had a history of type 2 diabetes mellitus and dyslipidemia diagnosed in December 2024, and was taking metformin and simvastatin. He began experiencing significant weight loss, asthenia, and gastroenteritis in April 2024. In November 2024, he developed painful, indurated nodular lesions in the left temporal region, with rapid dissemination to the central face and hands, progressing to central ulceration and crusting, particularly on the hands and nasal ala, with nasal collapse and congestion. The lesions progressed to the trunk, thighs, and toe web spaces, with infected ulceration and foul-smelling greenish discharge. He denied fever and other associated complaints throughout the course. In February 2025, he was admitted to a tertiary care hospital. Skin biopsy, cultures, and investigations were performed to rule out differential diagnoses including syphilis, leprosy, tuberculosis, and fungal infections. While awaiting biopsy and serologic results, secondary skin and soft tissue infection was treated with ceftriaxone and clindamycin for 10 days, and he was discharged on amoxicillin/clavulanate for 7 days with outpatient follow-up. After confirmation by biopsy and immunohistochemistry consistent with tegumentary leishmaniasis, he was referred for in-hospital specific therapy due to the disseminated form. He received liposomal amphotericin B for 11 days (total dose 2,100 mg), along with ceftriaxone and clindamycin for 16 days because of persistent secondary bacterial infection. He showed significant clinical improvement of disseminated lesions and respiratory symptoms. At follow-up 15 days after discharge, there was marked improvement of facial and limb lesions and complete regression of crusts on the fingers, with lesions in an advanced stage of healing. The presentation with extensive skin lesions and mucosal involvement initially suggested systemic mycoses or other granulomatous dermatoses. Confirmation of disseminated leishmaniasis in this patient, a rare form, reinforces the importance of including it in the differential diagnosis.