Chromoblastomycosis and phaeohyphomycotic abscess-associated hospitalizations, United States, 2016-2021.

Background: Chromoblastomycosis and phaeohyphomycotic abscesses are infections of the skin and subcutaneous tissues caused by dematiaceous fungi; more rarely, phaeohyphomycotic brain abscesses can occur. The epidemiology and clinical outcomes of chromoblastomycosis and phaeohyphomycotic abscesses are not well-understood in the United States.

Methodology/ principal findings: We used data from the Healthcare Cost and Utilization Project's National Inpatient Sample to obtain yearly national estimates of chromoblastomycosis and phaeohyphomycotic abscess-associated hospitalizations. We examined age group, sex, Census region, season of hospital admission, clinical form of chromoblastomycosis, and presence of selected concurrent conditions. An estimated 690 chromoblastomycosis and phaeohyphomycotic abscess-associated hospitalizations occurred during 2016-2021. Rates were highest in 2016 (0.5/1,000,000) and lowest in 2020 (0.2/1,000,000). Overall, higher hospitalization rates occurred among males (0.4/1,000,000) versus females (0.3/1,000,000). Rates increased with age, with patients aged ≥65 years having the highest rate (0.9/1,000,000). The Northeast had the highest hospitalization rate (0.5/1,000,000) followed by the South (0.4/1,000,000). Hypertension (34%), diabetes (33%), dyslipidemia (28%), and chronic kidney disease (21%) were the most common concurrent conditions. Nine percent had autoimmune inflammatory disease or solid malignancy. Seven percent had solid organ or stem cell transplantation. Subsequently, five percent had lymphedema. Mean hospitalization length was 9.9 days; in-hospital death occurred in 3%.

Conclusions/significance: Substantial in-hospital mortality and complications like lymphedema can occur from chromoblastomycosis and phaeohyphomycotic abscesses. Our analysis provides a baseline to monitor hospitalizations and mortality along with comorbidities that may change these outcomes. Public health and clinical partnerships could improve understanding of these fungal diseases caused by dematiaceous fungi through registries, enhanced surveillance, and increased awareness.