Intractable Nocardial mycetoma with possible colonisation by Candida species

A Japanese male in his 30s with no underlying medical condition presented with painless nodules after being bitten by a dog during a stay in Bali, Indonesia, 7 years earlier. He was referred to our department with multiple ulcers, nodules, and masses on the right leg. The final diagnosis was mycetoma caused by Nocardia vulneris, which may have been exacerbated by colonization of Candida parapsilosis and C. tropicalis as these yeasts were isolated by culture from the tissue. Treatment with minocycline hydrochloride and sulfamethoxazole trimethoprim showed partial efficacy, but the addition of posaconazole achieved significant efficacy. This suggests that the surmised coexistence of pathogenic yeasts of lower virulency may have made mycetoma in this case intractable.