Disclosed herein are methods for diagnosing a subject with loss and/or distortion of taste or smell, e.g., hyposmia, dysosmia, anosmia, phantosmia, hypogeusia, dysgeusia, phantogeusia, and/or ageusia. Also disclosed herein are methods and compositions for treating a subject for loss and/or distortion of taste or smell, e.g., hyposmia, dysosmia, anosmia, phantosmia, hypogeusia, dysgeusia, phantogeusia, and/or ageusia.