Acupuncture may be an effective treatment for post-viral infection loss of smell

Olfactory dysfunction can arise from a variety of causes and can profoundly influence a patient's quality of life. The sense of smell determines the flavor of foods and beverages and also serves as an early warning system for the detection of environmental hazards, such as spoiled food, leaking natural gas, smoke, or airborne pollutants. The loss or distortions of smell sensation can adversely influence food preference, food intake, and appetite.

Approximately 2 million Americans experience some type of olfactory dysfunction. One of the most frequent causes of loss of smell in adults is an upper respiratory tract infection (URI). Patients usually complain of smell loss following a viral URI. The smell loss is most commonly partial, and reversible. However, occasionally patients may also present with parosmia (a distortion of the sense of smell), phantosmia (smelling things that aren't there), or permanent damage of the olfactory system.

To date, there is no validated pharmacotherapy for PVOD, but attempts have been made to establish a standardized treatment. In the literature, systemic and topical steroids as well as vitamin B supplements, caroverine, alpha lipoic acid, and other drugs were used to treat patients. The researchers point out that in addition to these treatments, complementary and alternative medicines are currently being employed by many patients on their own, and that exploration into their usefulness by traditional Western medicine should be validated.

In the current study, 15 patients presenting to an outpatient clinic with PVOD were treated by TCA in 10 weekly 30-minute sessions. Subjective olfactometry was performed using the Sniffin' Sticks test set. Treatment success was defined as an increase of at least six points in the sticks test scores. The effects of TCA were compared to matched pairs of people suffering from PVOD who had been treated with vitamin B complex. Eight patients treated with TCA improved olfactory function, compared with two treated with vitamin B complex.

The authors acknowledge that their study is limited by its size, and that further studies should be conducted in a larger population. However, the authors write "…the observed high response rate of about 50 percent under TCA was superior to that of vitamin B complex or that of spontaneous remission, and offers a possible new therapeutic regimen in postviral dysosmia."