Persistent olfactory dysfunction in mild COVID-19 patients: A descriptive study of the characteristics and association with other symptoms

• Published in: Medicina clinica Vol. 160; no. 8; p. 347
• Main Authors: García-Meléndez, David Dylan, Morales-Casado, María Isabel, Quintana Castro, Pilar, Marsal Alonso, Carlos
• Format: Journal Article
• Language: English
• Published: Spain 21.04.2023
• Subjects: Adult; COVID-19 - complications; Humans; Olfaction Disorders - diagnosis; Olfaction Disorders - epidemiology; Olfaction Disorders - etiology; Prevalence; Smell; COVID-19; Niebla mental; Olfactory dysfunction; Parosmia; Brain fog; COVID persistente; Anosmia; Alteración olfatoria; Long COVID
• ISSN: 1578-8989
• DOI: 10.1016/j.medcli.2022.11.018

Post-COVID olfactory dysfunction continues to be studied due to the controversy of the mechanisms involved. The aim was to investigate the olfactory dysfunctions in association with other post-COVID symptoms. Observational, descriptive and single-center study. The patients had confirmed mild COVID-19 and subjective olfactory dysfunction of more than a month of evolution, which was assessed by Sniffin' Sticks Olfactory Test. A total of 86 patients participated. The mean age was 37.2 years (SD 9.82). 70.9% reported parosmia and 46.5% symptoms of brain fog. A pathological test result was obtained in 72.1% of the participants. The most failed pen was 11 (apple) in 76.7%. Anosmia of pen 15 (anise) was reported more frequently in 24.4% and cacosmia of pen 9 (garlic) in 27.9%. We observed a significant association between patients who reported parosmias and brain fog (RR 2.18; p=0.018), also between parosmia and phantosmia (RR 6.042; p<0.001). There is some pathological selectivity for certain test pens, a higher prevalence of cognitive symptoms and many patients with combined parosmia and brain fog.