Prevalence of Taste and Smell Dysfunction in Coronavirus Disease 2019

This survey study of patients with coronavirus disease 2019 investigates the presence of sinonasal manifestations at the onset of the disease to achieve an earlier diagnosis. Question Are there relevant sinonasal manifestations associated with the onset of coronavirus disease 2019? Findings This survey study of 204 patients with coronavirus disease 2019 found that taste reduction was present in 55.4% of patients, whereas smell reduction was present in 41.7% of patients. Severe nasal obstruction was uncommon at the onset of the disease (7.8%). Meaning The findings suggest that coronavirus disease 2019 should be suspected when severe reduction of taste and smell are present in the absence of nasal obstruction. Importance Early diagnosis of coronavirus disease 2019 (COVID-19) may help control the diffusion of the disease into the population. Objective To investigate the presence of sinonasal manifestations at the onset of COVID-19 to achieve an earlier diagnosis. Design, Setting, and Participants This retrospective telephone survey study investigated patients diagnosed with COVID-19 from March 5 to March 23, 2020, who were hospitalized or discharged from a single referral center. Patients who were unable to answer (intubated, receiving noninvasive ventilation, or deceased) or unreachable by telephone were excluded. Of 359 consecutive patients, 204 fulfilled the inclusion criteria; 76 were unable to answer, 76 were unreachable by telephone, and 3 refused. Exposures Sinonasal manifestations reported before COVID-19 diagnosis were studied with a validated questionnaire: Italian Sino-Nasal Outcome Test 22 (I-SNOT-22). If reduction of taste and/or smell was documented by item 5 of the I-SNOT-22, further inquiries were made to score them separately on a scale from 0 to 5, with 0 indicating no problem and 5 indicating problem as bad as it can be. Main Outcomes and Measures The prevalence of sinonasal manifestations preceding COVID-19 diagnosis. Results Among the 204 patients enrolled (110 [53.9%] male; mean [SD] age, 52.6 [14.4] years), the median I-SNOT-22 total score was 21 (range, 0-73). I-SNOT-22 identified 116 patients (56.9%) with reduction of taste and/or smell, 113 (55.4%) with taste reduction (median score, 5; range, 2-5), and 85 (41.7%) with smell reduction (median score, 5; range, 1-5). Eighty-two patients (40.2%) reported both. Severe reduction of taste was present in 81 patients (39.7%), and severe reduction of smell was present in 72 patients (35.3%). Only 12 patients (14.8%) with severe taste reduction and 12 patients (16.7%) with severe smell reduction reported severe nasal obstruction. Severe reduction of taste and smell was more prevalent in female vs male patients (odds ratios, 3.16 [95% CI, 1.76-5.67] vs 2.58 [95% CI, 1.43-4.65]) and middle-aged vs younger patients (effect sizes, 0.50 [95% CI, 0.21-0.78] vs 0.85 [95% CI, 0.55-1.15]). No significant association was observed between smoking habits and severe reduction of taste (odds ratio, 0.95; 95% CI, 0.53-1.71) and/or smell (odds ratio, 0.65; 95% CI, 0.35-1.21). Conclusions and Relevance The findings of this telephone survey study suggest that reduction of taste and/or smell may be a frequent and early symptom of COVID-19. Nasal obstruction was not commonly present at the onset of the disease in this study. The general practitioner may play a pivotal role in identifying potential COVID-19 in patients at an early stage if taste and/or smell alterations manifest and in suggesting quarantine before confirmation or exclusion of the diagnosis.