Abstract
Sickle cell trait (SCT) is typically asymptomatic, but high-altitude exposure and intense exertion can trigger complications, such as splenic infarction. We herein report the case of a 24-year-old African-American man of Haitian descent who developed flank pain after climbing Mt. Fuji. Contrast-enhanced computed tomography revealed splenic infarction, and an anaerobic blood culture test demonstrated sickled red blood cells. High-performance liquid chromatography confirmed SCT. Of the 13 reported cases in Japan, 92.3% occurred on Mt. Fuji, and all involved foreigners, underscoring the risk posed by rapid ascent and hypoxia. Greater awareness, screening, and education are crucial for preventing these high-altitude complications.