Chromoblastomycosis in northern Taiwan from 2017 to 2024: unique characteristics

Background: Chromoblastomycosis (CBM) is an implantation mycosis caused by dematiaceous fungi in the tropical and subtropical regions. It is a neglected tropical disease that primarily affects populations living in poverty. Although located in tropical and subtropical regions, Taiwan is a highly industrialized country with an advanced healthcare system that offers a unique perspective on CBM. Objectives: To explore the epidemiology, clinical characteristics and treatment outcomes of patients with CBM in northern Taiwan. Methods: This study included 14 patients who were pathologically diagnosed with CBM at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan, between January 2017 and August 2024. The relevant clinical profiles were analysed. The pathogens were isolated by fungal culture and identified using sequence-based methods. Results: The mean age was 65.4 (SD 10.4) years, and 93% (13/14) of the patients were male. The median time between onset and diagnosis was 6.5 (interquartile range 3.0–36.0) months. In addition to the common comorbidities, we identified four hepatitis B carriers and two patients who were immunosuppressed. Although there were four patients who had occupations requiring physical labour, nine patients were either retired or engaged in sedentary work and their leisure activities included gardening (this information was not available for one patient). Pathogens were isolated from 13 patients, all of which were identified as Fonsecaea monophora. Treatments included systemic and topical antifungal agents, surgical excision, local thermotherapy and cryotherapy, with 71% (10/14) patients achieving complete response. Conclusions: Patients with CBM in Taiwan are characterized by older age and, in some, a history of gardening-related trauma or immunosuppression. We also report a shorter delay from disease onset to diagnosis and a good complete response rate, which may reflect better medical accessibility.