Deep cutaneous mycoses in kidney transplant recipients: Diagnostic and therapeutic challenges

Deep cutaneous mycoses (DCMs) are rare infections that extend throughout the dermis and subcutis, often occurring after inoculation with pathogenic fungi. Trends toward a growing incidence have been observed that may be partially related to an increasing population of solid organ transplant patients. The aim of this study is to describe the diagnostics and the outcomes of DCM among kidney transplant recipients so as to optimize their management. We performed a retrospective review of cases of DCM occurring among kidney transplant recipients in our institution over 12 years. Twenty cases were included. Lesions were only located on the limbs and presented mainly as single (10/20, 50%) nodular lesions (15/20, 75%), with a mean size of 3 cm. Direct mycological examination was positive for 17 patients (17/20, 85%) and the cultures were consistently positive. Thirteen different fungal species were observed, including phaehyphomycetes (n = 8), hyalohyphomycetes (n = 3), dermatophytes (n = 1), and mucorale (n = 1). The (1-3) beta-D-glucan antigen (BDG) was also consistently detected in the serum (20/20, 100%). Systematic imaging did not reveal any distant infectious lesions, but locoregional extension was present in 11 patients (11/14, 79%). Nineteen patients received antifungal treatment (19/20, 95%) for a median duration of 3 months, with surgery for 10 (10/20, 50%). There is a great diversity of fungal species responsible for DCMs in kidney transplant recipients. The mycological documentation is necessary to adapt the antifungal treatment according to the sensitivity of the species. Serum BDG positivity is a potentially reliable and useful tool for diagnosis and follow-up.