Introduction Acute upper respiratory infection (AURI) is the most common cause of postinfectious olfactory dysfunction (PIOD). Objective We investigated the prevalence of PIOD in a large group of patients reporting persistent smell impairment perception after the AURI resolution. Methods Olfactometry was performed within 1 month after the common cold resolution and after 1 year in 467 (299 males, mean age 41.7 years) outpatients. The Sniffin' Sticks olfactory test (Burghart instruments, Wedel, Germany) was used. Results Anosmia was documented in 28 (6%) patients, hyposmia in 33 (7%), and cacosmia in 55 (11.7%). After 1 year, PIOD improved in 82 (79.6%) patients re-tested. Conclusion The current study demonstrated that persistent olfactory dysfunction is a relevant symptom in patients with AURI, even though many patients had normal olfactometry. Thus, smell impairment deserves careful attention and requires objective documentation.
Keywords: acute upper respiratory infection; olfactometry; olfactory dysfunction.
Fundação Otorrinolaringologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).