A case of melanonychia caused by Fusarium solani

Sir, Fusarium sp. accounts for about 5% of all the moulds isolated from nails with suspected onychomycosis,1 and has increasingly been recognized as a cause of disseminated and often fatal hyalohyphomycosis in immunocompromised patients.2,Fusarium sp. rarely causes blackish pigmentation of infected nails and only a few cases have been reported inthe literature.1–3 Here we report a rare case of fungal melanonychia due to Fusarium solani in an otherwise healthy man. A 64‐year‐old Korean man presented with a 4‐year history of black pigmentation in all of his left, in his right first to third fingernails, and in both great toenails (Fig. 1). The discoloration began at both fingernails 4 years before and spread to both great toenails 2 years later. He was in good health with normal laboratory findings. There was no past history of any drug intake, trauma, or nail abnormalities. Direct microscopic examination of the ungal fragments in 20% KOH showed hyaline septate hyphae of irregular diameter. Cultures on Sabouraud dextrose agar and potato corn meal Tween 80 agar with chloramphenicol with or without cyclohexamide at 25 °C grew numerous floccose pale pink colonies on three consecutive cultures. The culture mount in lactophenol cotton blue showed numerous sickle‐shaped, multiseptate macroconidia and septate, branched hyphae of irregular size (Fig. 2). A diagnosis of melanonychia due to F. solani was made. Clinical improvement was noted within 3 months with pulsed itraconazole therapy at a dose of 400 mg per day for 7 days, for two consecutive months.