About Taste and Smell
Over two million Americans complain of smell and taste problems, and over one-quarter million visit a physician for this problem each year. Twenty-five percent of the population over age fifty-five have an age associated smell and taste impairment, and are often not aware of this problem. In the elderly, these disorders can lead to unexplained weight loss, depression and poor appetite.
People with a faulty sense of smell and taste can be deprived of an early warning system that we all take for granted. Poisonous fumes, leaking gas, and spoiled foods can interfere with our health and safety if not recognized. Increased salt and sugar intake to improve palatability of food can aggravate high blood pressure and diabetes. Some professions require a keen sense of smell, such as chef or a firefighter. Therefore, disorders of smell and taste in these professions can lead to job loss and serious economic hardship. For the rest, smell and taste disorders may simply mean a diminished quality of life.
Smell and taste are a part of our sensing system much like vision and hearing. Molecules released by substances around us stimulate special nerve cells in the nose, mouth or throat. These special nerve cells transmit electric impulses to special areas of the brain that recognize smell and taste.
Olfactory nerve cells are stimulated by odors
around us such as flowers, baked goods, perfumes, etc.. These olfactory
nerve cells are located in a tiny patch high up in the nose. They
connect by nerve pathways to areas in the brain.
The Most common cause is aging. Smell loss is more common than taste loss. The sense of smell is most accurate between the ages of thirty and sixty. After sixty, smell loss begins to accelerate. By age sixty-five to eighty, half have moderate to severe loss. Above age eighty, seventy-five percent have moderate to severe smell loss.
Besides aging, about twenty percent of smell and taste disorders are due to viral infections which damage the smell receptors in the nose. another twenty percent are due to diseases of the nasal cavity, including polyps, sinusitis and allergies. An additional twenty percent are due to various medications, smoking, vitamin deficiency, brain tumors, chemical exposure, and effects of radiation. Smoking impairs both smell and taste. Stopping smoking may preserve function. It may take a number of years to restore the sense of taste and smell lost from smoking. Head trauma causes twenty percent of smell and taste complaints. Many neurological disorders, like Alzheimer's disease, stroke, Parkinson's disease, and Lewy Body dementia are associated with smell and taste disorders. They often go unnoticed an unrecognized as a cause of weight loss, decreased appetite, and depression. As many as ten to twenty percent of taste and smell disorders do not have an identifiable cause.
An easily administered scratch and sniff test developed by the University of Pennsylvania Smell & Taste Clinic is a very sensitive and reliable test to detect smell disorders. The taste evaluation relies on whole mouth testing of different tastants such as solutions of sweet, sour, bitter and salt. Also, taste evolution can be specifically tested on different areas of the tongue.
When you make your appointment you will receive an information packet, which includes a comprehensive personal history questionnaire. You will need to complete the questionnaire and bring it with you when you come for your evaluation. This questionnaire asks about your medical history, and about your particular smell and taste problems. This information, along with your examination and testing, are needed in the evaluation and diagnosis of your disorder.
When you arrive you will be seen by the neurologist who will discuss your history with you and do a brief neurological examination. You will then undergo the battery of smell and taste tests described above. This entire process can take approximately one to one and a half hours.
After all of the testing is completed you will visit with the neurologist again to discuss the results. Depending on the outcome, you may be advised that further studies are indicated, such as an MRI or CT scan of the head and sinuses, or possibly blood tests. These blood tests may include, B-12 and thyroid levels, kidney and liver function tests. The neurologist may also recommend further evaluation by an ear, nose and throat specialist.
Based on the results of the tests, and history of your smell and taste problem, a treatment plan can be developed in many cases. You will be given as much information available regarding the cause and prognosis of your problem.
Medication contributing to smell and taste loss may be withdrawn or altered in dosage, but only after consultation with your prescribing physician. Discovering that the disorder is a result of head trauma, the lingering effects of a viral infection, or merely part of the aging process can help to reduce anxiety and worry. In ten to fifteen percent of head trauma and viral infections, smell and taste loss can improve over time.
There is currently no specific medication proven to be effective in treating smell and taste loss. Our clinic has experience with recipes that can improve palatability of foods and eating enjoyment. We will work with you to create personalized recipes and menus, based on your needs, as determined by the results of your evaluation.