COVID-19 Status Differentially Affects Olfaction: A Prospective Case-Control Study.

Objective: The symptoms and long-term sequelae of SARS-CoV-2 infection have yet to be determined, and evaluating possible early signs is critical to determine which patients should be tested and treated. The objective of this ongoing study is to evaluate initial and short-term rhinologic symptoms, olfactory ability, and general quality of life in patients undergoing SARS-CoV-2 testing.

Study Design: Prospective case-control.

Setting: Academic institute.

Methods: Adult patients tested for SARS-CoV-2 were prospectively enrolled and separated into positive and negative groups. Each participant completed 4 validated patient-reported outcome measures. The UPSIT (University of Pennsylvania Smell Identification Test) was distributed to patients who were SARS-CoV-2 positive.

Results: The positive group reported significantly decreased sense of smell and taste on the 22-item Sinonasal Outcome Test (SNOT-22) as compared with the negative group (mean ± SD: 3.4 ± 1.7 vs 1.2 ± 1.4, < .001). The positive group had a much higher probability of reporting a decrease in smell/taste as "severe" or "as bad as it can be" (63.3% vs 5.8%) with an odds ratio of 27.6 (95% CI, 5.9-128.8). There were no differences between groups for overall SNOT-22 domain scores, PHQ-4 depression/anxiety (Patient Health Questionnaire-4), and 5-Level EQ-5D quality-of-life scores. Mean Self-MOQ (Self-reported Mini Olfactory Questionnaire) scores were 7.0 ± 5.6 for the positive group and 1.8 ± 4.0 for the negative group ( < .001). The mean UPSIT score was 28.8 ± 7.2 in the positive group.

Conclusion: Symptomatic patients who are SARS-CoV-2 positive report severe olfactory and gustatory dysfunction via the Self-MOQ and SNOT-22 as compared with symptomatic patients testing negative.