OBJECTIVETo investigate whether patients presenting with self-reported olfactory disorders demonstrates significant side difference in odour recognition by measuring separately for each nostril.

METHODSOne hundred and four patients with chief complaint of hyposmia were evaluated by medical history, physical examination, T&T olfactory testing and medical imaging. Smell was tested using T&T olfactometry in each nostril separately.

RESULTSBased on the history and results from the clinical examination, unilateral sinonasal diseases and abnormal nasal structure were excluded. In almost one eighth of all presenting patients (13.46%), a side difference was detected. Especially, six of the patients were identified with lateralized hyposmia.

CONCLUSIONSOlfactory testing could be performed in each nostril separately. The above findings suggested that testing each nostril separately was necessary so as not to miss unilateral hyposmia as a special clinical manifestation of olfactory disorder.