| Smell and Taste Disorders |
Disorders of smell and taste can have a large impact on quality of life. Currently
about 2 million adults in the United States are evaluated for smell and taste
disorders every year, but it is believed many more cases go unreported. It
is estimated that up to 80% of taste is a result of olfactory (or smell) input.
As a result loss of smell is frequently interpreted as a loss of taste.
Olfactory (small nerve) cells are stimulated by odors. These nerve cells are
found in a tiny patch of tissue located high up in the nose and they connect
directly to the brain. Taste cells react to food or drink mixed with saliva.
The taste cells are located in the taste buds located on the surface of the
tongue. These surface cells send taste information to nearby nerve fibers,
which send messages to the brain.
The olfactory pathway can be disrupted by conductive or sensory neural causes.
Conductive disruptions are caused by nasal air flow obstruction. Examples
of these include chronic rhinosinusitis, polyps, allergic rhinitis and tumors.
Sensory neural causes occur with damage to the olfactory nerves themselves.
Examples of these include loss of smell after an upper respiratory infection,
head trauma or other neurological disorders.
Evaluations of these disorders include a thorough history and physical exam
with an endoscope, “scratch and sniff” smell testing, taste testing including
the sip, spit and rinse and often imaging usually involving a CT scan.
Treatment depends on the classification and the severity of the loss. Some
losses caused by a medication will recover as soon as the medication is stopped.
Many of the conductive causes can be managed with the use of anti-inflammatory
medications or surgery if the medical treatments fail. Typically sensory neural
losses do not respond to medical or surgical treatments. Instead changes over
time will indicate improvement.
See the selected publications
to review ongoing research in this area by physicians and surgeons at the