Smell loss can happen for a variety of reasons, but a common cause is chronic rhinosinusitis, with or without nasal polyps. It can also be caused by head trauma, or a cold that is likely related to a virus. Sometimes there is no explanation for a smell loss. It is more common in older age groups.
A smell loss is often brought to the patient’s attention because they notice a difficulty in tasting food. This is because flavor is a combination of smell and taste. With a smell loss, the taste of food is reduced to a very bland sensation.
There are nerves that are responsible for detecting odors located in the upper part of the nasal cavity. Smell loss happens when there is a blockage of airflow getting to those nerves (perhaps by chronic rhinosinusitis or swelling of nose), or when there is direct damage to the nerves or to the areas of the brain where that sense of smell is processed (perhaps by viral infection or head trauma).
Besides the loss of sense of smell, some patients experience a distorted smell, or a “phantom” smell (an odor that other people can’t smell).
Your physician will evaluate the smell loss through an extensive discussion on the history and by an endoscopic examination of the nasal cavity. There is also a smell test available that is performed in the Sinus Center. Depending on the results, further testing such as an MRI or CT scan may be ordered.
Unfortunately there are not many therapies available to patients with smell loss. In cases where the smell loss is caused by chronic rhinosinusitis, medication (topical nasal steroids, allergy treatments, or saline nasal washes) or surgery for treating that condition may be helpful. Oral steroids might be helpful in treating certain forms of smell loss, but they may provide only short term benefit.
Often patients come into the Sinus Center under the impression that they have taste loss, when it is actually a smell loss. This is because, as described above, the flavor of food is a combination of smell and taste.
But there are some patients with a true taste loss, though it is much less common than smell loss. It is difficult to have a complete taste loss, because taste is processed by the surface of the tongue and by three different nerves. It is more common to have decreased or altered taste (often described as “metallic”) than a total taste loss.
True taste loss has many causes, including infection, central brain disorders, nutritional deficits, or complications in surgery of the mouth or ear.
An important part of evaluating a taste loss is to first make sure that it is not a smell loss instead. Your physician will evaluate the taste loss through an extensive discussion of the history and by an endoscopic examination of the nasal cavity. There is also a taste test available that is performed in the Sinus Center. Depending on the results, further testing such as an MRI or CT scan may be ordered.
The ability to treat a taste loss depends on the ability to identify the cause. If infection is the underlying cause, it can be treated with antibiotic or antifungal medications. In many cases, the cause of taste loss is unknown.