A 49-year-old man living on an island was admitted to our hospital in January with antibiotic-resistant intermittent fever, cough, and hypoxemia. Based on his medical history, imaging findings, and a positive test for anti-Trichosporon asahii antibody, we diagnosed summer-type hypersensitivity pneumonitis. A literature review of reported cases of summer-type hypersensitivity pneumonitis diagnosed in seasons other than summer showed that it is common in hot and humid environments as well as in warm regions. The possibility of summer-type hypersensitivity pneumonitis should be considered even in winter.
