Onychomycosis caused by Aspergillus subramanianii

We describe a case of a 23-year-old female patient with no apparent underlying diseases. She showed a discoloration of the proximal portion of the left big toenail with paronychia. Direct microscopy revealed septate hyphae with conidiophores, and a periodic acid-Schiff-stained nail specimen revealed septate hyphae branching at angles of approximately 45°. On the basis of phylogenetic analysis, we finally arrived at the diagnosis of ungual aspergillosis caused by Aspergillus subramanianii. After p.o. administration of terbinafine and topical application of 10% efinaconazole solution, the disease resolved in 6 months. A. subramanianii is one of the new species in the genus Aspergillus section Circumdati. Reported clinical isolates have been isolated from lung tissue, wounds and feet. This is the first documented case of onychomycosis caused by A. subramanianii. Onychomycosis due to Aspergillus species is uncommon. We summarized the reported cases of ungual aspergillosis in Japan.