First case of disseminated phaeohyphomycosis in an immunocompetent individual due to Alternaria malorum

Abstract

A 27-year-old Iranian, previously healthy male presented with sub-cutaneous necrotic lesions with a localized dermatosis affecting the anterior chest, neck and face. These lesions consisted of singular, well-defined verrucous plaques which gradually developed and disseminated over time. The dermatosis was followed by the development of necrotic swollen lesions localized on the hard palate. The patient did not recall any history of trauma or puncture at any of the sites of infection. While histopathological examination of periodic acid-Schiff (PAS) stained material revealed irregular, unbranched, septate hyphae, direct examination (KOH 10%) of lesion samples demonstrated the presence of septate indistinct brownish hyphae. Alternaria malorum was isolated (CBS 126589) and its identity was confirmed by sequencing of the internal transcribed spacer (ITS rDNA). Since the palate lesion reoccurred after 10 years and the patient's condition did not improve with amphotericin B combination therapy, the lesion was surgical excised and he underwent antifungal therapy with amphotericin B and itraconazole. There was no dehiscence or fistula formation or any evidence of relapse of fungal infection during a one year follow-up and the patient was successfully cured. In vitro antifungal susceptibility tests revealed that the MIC values for those antifungals employed in this case were amphotericin B (0.125 μg/ml), fluconazole (32 μg/ml), itraconazole (0.125 μg/ml), voriconazole (1 μg/ml), and posaconazole (0.063 μg/ml). The MECs for caspofungin and anidulafungin were 0.25 μg/ml and 0.016 μg/ml, respectively. However, treatment of A. malorum infections with the latter agents remains to be evaluated.