High Altitude Pulmonary Edema Associated with Climbing Mount Fuji.

A 51-year-old man presented to the emergency department with rapidly progressive dyspnea that developed while climbing Mount Fuji. He had climbed Mount Fuji twice without experiencing similar symptoms. On arrival, his oxygen saturation was 91% on 10 L/min of oxygen with a non-rebreather mask. Chest imaging revealed scattered bilateral infiltrating shadows. He was diagnosed with high-altitude pulmonary edema (HAPE) and treated with high-dose corticosteroids, calcium-channel blockers, antibiotics, and oxygen via a high-flow nasal cannula. The patient responded to treatment and was discharged on day 7. Climbers should be aware of the risk of HAPE when climbing Mount Fuji.