Two patients developed dark pigmentation on their toenails caused by rare combinations of fungal infections. Through laboratory testing and genetic analysis, doctors identified fungi never before known to cause this type of nail discoloration. Both patients were successfully treated with an antifungal medication called efinaconazole, with complete resolution of symptoms within a few months.
This paper describes two unusual cases where fungal infections of the toenails caused dark pigmentation (melanonychia). The first patient had a combination of two fungi (Aspergillus hiratsukae and Trichosporon faecale) causing black nail streaks, while the second had Exophiala xenobiotica and Trichophyton interdigitale causing dark-brown discoloration. Both patients were successfully treated with an antifungal medication called efinaconazole over several months.
A 20-year-old woman suffered from a persistent toenail infection that didn’t respond to several standard antifungal treatments over five years. Researchers identified the culprit as Yarrowia lipolytica, a rare yeast not previously known to cause nail infections. Testing showed this yeast was resistant to common antifungal medications the patient had received, explaining why previous treatments failed. This unusual case highlights the importance of properly identifying fungal pathogens and testing them for drug resistance before starting treatment.