Smell and taste disorders: a primary care approach.

Smell and taste disorders are common in the general population, with loss of smell occurring more frequently. Although these disorders can have a substantial impact on quality of life and may represent significant underlying disease, they are often overlooked by the medical community. Patients may have difficulty recognizing smell versus taste dysfunction and frequently confuse the concepts of "flavor" and "taste." While the most common causes of smell disturbance are nasal and sinus disease, upper respiratory infection and head trauma, frequent causes of taste disturbance include oral infections, oral appliances (e.g., dentures), dental procedures and Bell's palsy. Medications can interfere with smell and taste, and should be reviewed in all patients with reported dysfunction. In addition, advancing age has been associated with a natural impairment of smell and taste ability. A focused history and a physical examination of the nose and mouth are usually sufficient to screen for underlying pathology. Computed tomographic scanning or magnetic resonance imaging of affected areas, as well as commercially available standardized tests, may be useful in selected patients. The causes of olfactory dysfunction that are most amenable to treatment include obstructing polyps or other masses (treated by excision) and inflammation (treated with steroids). Enhancement of food flavor and appearance can improve quality of life in patients with irreversible dysfunction.