Propriety of various examinations for subjective symptoms of olfactory disorders.

Purpose: In Japan, two types of tests for diagnosing olfactory disorders, T and T (T&T) olfactometry and intravenous olfactory tests, are covered by insurance and performed on patients with olfactory disorders. This study examined the validity of these olfactory tests and whether psychophysical or morphological tests are more helpful in evaluating olfactory disorders.

Methods: We evaluated patients who visited our department and underwent two types of olfaction tests and sinus computed tomography (CT). Data regarding the age, sex, peripheral blood eosinophil percentage, presence of bronchial asthma, diagnoses, olfactory symptom score, results of the two olfactory tests, and CT findings in eligible patients were extracted from medical records and retrospectively reviewed.

Results: One hundred and sixty-three patients underwent all tests during the study period. The results of the T&T olfactometry and intravenous olfactory tests were significantly correlated. However, only the results of T&T olfactometry and olfactory cleft opacification on CT were statistically significant predictors of the olfactory symptom scores.

Conclusion: T&T olfactometry and CT evaluations of olfactory cleft opacification helped evaluate olfactory dysfunction. It is important to note that intravenous olfactory tests are best performed with careful control and not blindly to assess olfactory disorders.