Disseminated histoplasmosis presenting with polymorphic mucocutaneous lesions in a renal transplant recipient

Disseminated histoplasmosis is an opportunistic fungal infection caused by Histoplasma capsulatum that commonly affects immunocompromised individuals. Cutaneous manifestations are polymorphic and may mimic several dermatological disorders, leading to diagnostic difficulty. We report a 33-year-old renal transplant recipient on tacrolimus and mycophenolate mofetil who presented with a 6-month history of progressive ulcerative cutaneous lesions associated with hemorrhagic crusting, intermittent low-grade fever, pain, and weight loss. Examination revealed multiple ulcerative plaques with surrounding erythema over the trunk, limbs, and face, along with erythematous to brown nodules over the extremities. Oral, genital, and conjunctival mucosal involvement was also present. Laboratory tests showed anemia, leukocytosis, and renal dysfunction, with negative human immunodeficiency virus serology. Histopathology of the cutaneous lesion revealed clusters of small yeast-like organisms within histiocytes, highlighted by periodic acid–Schiff stain, confirming the diagnosis of histoplasmosis. The patient was started on amphotericin B. This case highlights the importance of maintaining a high index of suspicion for deep fungal infections in immunosuppressed patients presenting with chronic, non-healing ulcerative or nodular skin and mucosal lesions and also emphasizes the varied mucocutaneous manifestations of disseminated histoplasmosis in transplant recipients. Timely biopsy, special staining, and clinicopathological correlation are essential for accurate diagnosis and prompt initiation of antifungal therapy.