Concurrent chromoblastomycosis and eumycetoma: a unique case of dual neglected tropical fungal diseases in Asia

Chromoblastomycosis (CBM) and mycetoma, as implantation mycoses, have been listed as neglected tropical diseases (NTDs) by the World Health Organization. The concurrent occurrence of these two NTDs in a single patient is extremely rare. A 69-year-old female patient presented with papules on the dorsum of her left hand for over 5 months and nodules on the left lower limb accompanied by ulceration and pain for 20 days. Histopathological examination of the papule on the dorsum of the left hand revealed muriform cells and fungal culture of the tissue identified Fonsecaea monophora. Microscopic examination of the purulent secretion from the ulcer on the left lower calf revealed the presence of grains, and the tissue culture result was Scedosporium apiosperma complex, with metagenomic next-generation sequencing further identifying S. dehoogii as the predominant pathogen. The clinical diagnosis was CBM caused by F. monophora combined with eumycetoma due to S. dehoogii. The patient was treated with voriconazole at a dosage of 200 mg twice daily for 4 weeks, after which the papules on the dorsum of the left hand and the ulcer on the left lower calf showed gradual improvement. This case represents the first reported instance of concurrent CBM caused by F. monophora and eumycetoma due to S. dehoogii, providing a novel perspective on the clinical manifestations and early identification of neglected implantation mycoses.