We sought to evaluate and review the clinical and histopathologic features of cutaneous infections caused by the environmental opportunistic fungus Alternaria observed in transplant recipients.

We conducted a retrospective study of cases of cutaneous alternariosis in transplant recipients given a diagnosis in 3 hospitals in Catalonia, Spain, between 1991 and 2001. The clinical and evolution features were reviewed. A panel of histopathologic features was evaluated by two independent observers in all cutaneous biopsy specimens.

In all, 9 transplant recipients (8 men and 1 woman) presenting opportunistic cutaneous alternariosis were studied. The patients were 4 renal, 2 cardiac, 1 liver, and 2 lung transplant recipients. All patients were treated with different immunosuppressive therapeutic regimes. The lesions were solitary (3 patients) or multiple grouped (6 patients): papules (4 patients), plaques (5 patients), inflammatory nodules (2 patients), and recurrent cellulitis with secondary ulceration (1 patient), mainly located on the lower extremities. No extracutaneous involvement was detected. A previous traumatic event was recorded in two patients. A total of 12 cutaneous biopsy specimens were reviewed. Biopsy specimens from early lesions (<3 months evolution) were often characterized by the presence of epidermal changes (3/6 pseudoepitheliomatous hyperplasia; 50%), a diffuse dermal mixed inflammatory infiltrate of lymphocytes, plasma cells, histiocytes, neutrophils, and giant cells, and rare and focal granuloma formation. Dermal abscess or necrotizing folliculitis was occasionally noted. In biopsy specimens from more advanced lesions (>3 months evolution), the presence of a granulomatous inflammatory infiltrate was a constant feature. Suppurative granulomas (2/6; 33%) and sarcoidlike granulomas (2/6; 33%) were noted. In all biopsy specimens, fungal structures with a typical round-to-oval, thick refractile wall were identified.

Different clinical and histopathologic patterns can be noted in cutaneous alternariosis. Clinically the lesions manifest as solitary or grouped papules, plaques, or nodules mainly involving the lower extremities. Histologically, a relationship between the evolution of the cutaneous lesions and granuloma formation is detected. An increased awareness regarding the clinical and histopathologic features of cutaneous alternariosis in transplant recipients is important to achieve early detection and treatment.