Background: We report a case of hypersensitivity pneumonitis (HP) in a 17-year-old male student caused by Fusarium napiforme found in his home environment.
Methods: The patient was diagnosed according to history, chest radiograph, spirometry, high-resolution chest CT, and transbronchial lung biopsy. To identify the causative agent, cultured aeromolds were collected by the open-plate method. From the main fungi cultured, fungal antigens were prepared, and immunoblot analysis with the patient's serum and each fungal antigen was performed.
Results: Five fungal species were isolated from the patient's home. Immunoblotting analysis with the patient's serum demonstrated more than 10 IgG-binding fractions to F. napiforme extract only, while little binding was noted with the other fungal antigens.
Conclusions: We should be aware that HP may be caused by F. napiforme in the home environment.