Does hereditary hemorrhagic telangiectasia affect olfactory or gustatory function?

Background: The olfactory and gustatory functions of hereditary hemorrhagic telangiectasia (HHT) patients have not been documented by validated tests. Disorders of the nasal/oral cavity may interfere with the olfactory and gustatory functions. Fifty-four HHT patients were investigated by smell/taste tests.

Methods: HHT patients provided subjective ratings in areas such as ability to perceive smell/taste. "Sniffin' Sticks" were used for smell tests, and taste strips were used for taste tests.

Results: HHT patients rated their subjective olfactory and gustatory function on a visual analog scale from 0 (none) to 100 (high) as 65.3 ± 27.7 and 68.1 ± 25.1, respectively. Comparison of smell test results of HHT patients with normative data of sex- and age-matched controls from Hummel et al. revealed that HHT patients had lower threshold values, whereas there was no difference in identification and discrimination values. HHT patients were hyposmic. In the case of taste qualities, all values (sweet, sour, salty, and bitter) in HHT patients were lower than those in normative data of Mueller et al. However, HHT patients were not hypogeusic. The duration of disease, extranasal manifestation, and treatments did not significantly correlate with smell/taste test values.

Conclusion: Compared with healthy people, HHT patients exhibit reduced olfactory and gustatory function; however, HHT patients are hyposmic and not hypogeusic. This chemosensory deficit may highlight an early sign of disease and has no correlation with disease severity. HHT patients should be informed about these potential disease manifestations, thus enabling them to improve their quality of life.