Cutaneous phaeohyphomycosis caused by Alternaria infectoria.

Organ transplant recipients under immunosuppressive therapy have a highly increased risk of acquiring unusual opportunistic fungal infections. Therefore, diagnostics for uncharacteristic inflammatory skin lesions in transplant recipients must include an appropriate search for fungi. We recently diagnosed a renal transplant recipient with a cutaneous phaeohyphomycosis due to Alternaria infectoria, and a literature search revealed 3 similar previous reports in dermatological journals (1–3). This low number of observations is probably due to 2 factors: A. infectoria may be disregarded as a supposed contaminant by dermatologists; and strains may be identified with difficulty using conventional methods alone. Appropriate awareness and routinely applied genetic diagnostics may therefore lead to an increase in detection of A. infectoria infections. A 68-year-old renal transplant recipient was referred to our hospital with an unspecific painless and erythematous nodule on the lateral distal dorsal side of his right foot, which had developed within the last 2–3 months and had reached a diameter of approximately 3 cm (Fig. 1). The patient did not recall any preceding injury or trauma at this site. His general health had remained unchanged within the last months. He was under continuous immunosuppressive therapy with tacrolimus (4 mg daily), mycophenolate mofetil (1000 mg daily) and prednisone (5 mg daily). In addition, he was under therapy for hypertension, cardiac insufficiency, hyperlipidaemia and osteoporosis. He used insulin for his diabetes and took phenprocoumon. A skin biopsy was taken from the nodule on his foot because some kind of granulomatous reaction was clinically suspected. In this biopsy, multiple thick periodic acid-Schiff-positive unpigmented short hyphal and large thick-walled spherical fungal elements were detected in the dermis within a granu-lomatous infiltrate of histiocytes, macrophages, giant cells and other inflammatory cells (Fig. 2). Some fungal cells were surrounded by clear spaces. As a consequence of this finding, a chest X-ray and abdominal sonography were performed, but revealed no abnormalities. Furthermore, a second deep skin biopsy was taken from the lesion after meticulous skin surface disinfection for mycological cultures. Immediately after this second biopsy, an oral antimycotic treatment was initiated in consultation with the transplantation centre, starting with 400 mg itraconazole per day. Upon regression of the lesion this was tapered off to 200 mg/day after one week and to 100 mg/day after another 3 weeks in order to reduce interference with the immunosuppressive therapy. Additionally, topical application of ciclopiroxolamine was prescribed. After 2 months of therapy the lesion had healed. Mycology …