An updated review of clinical olfaction.

PURPOSE OF REVIEW: Disorders of the sense of smell can result through hundreds of different processes, but most commonly occur from upper-respiratory-tract infections, trauma, and chronic rhinosinusitis.

RECENT DEVELOPMENTS: Research in the basic science of olfaction has progressed rapidly with powerful new molecular discoveries; however, our ability to treat these disorders remains limited. In clinical olfaction we are just realizing the broader existence of the sensory dysfunction in our population. We are discovering associations between neurodegenerative disorders and smell function that may allow us to identify these disorders earlier in the disease process. We are also challenging our previous categorization schemes and realizing that many etiologies cross the traditional conductive and neuro-sensory divisions.

SUMMARY: Currently, aside from the possible therapeutic potential of systemic steroids, we have no effective treatment for the most common causes of olfactory loss. Recent advances in the basic science of olfaction provides us with an opportunity to develop new and novel clinical studies in an attempt at improving the quality of life for many of these patients.