This is the first update of the previously published living systematic review that summarized evidence on the prevalence of oral signs and symptoms in patients with COVID-19. Hitherto, 183 studies were included, reporting data from 64,876 patients with COVID-19 worldwide. The overall prevalence of taste disorders was 38% (95% CI = 22% to 56%, I2 = 98%). Hypogeusia, dysgeusia, and ageusia were also evaluated by a meta-analysis, and the pooled prevalence was 34% for hypogeusia, 33% for dysgeusia, and 26% for ageusia. Taste disorders were associated with a positive COVID-19 test (odds ratio [OR] = 7.54, 95% CI = 5.24 to 10.86, I2 = 93%, P < 0.00001), showing high certainty of evidence. However, the association between taste disorders and mild/moderate severity of COVID-19 (OR = 1.63, 95% CI = 1.33 to 1.99, I2 = 69%, P < 0.0001) and female patients with COVID-19 (OR = 1.77, 95% CI = 1.26 to 2.48, I2 = 79%, P = 0.001) presented low certainty of evidence. Xerostomia was a new feature of this update, and the pooled data demonstrated a prevalence of 43% (95% CI = 36% to 50%, I2 = 71%) in patients with COVID-19. Regarding oral mucosal lesions, the most common clinical pattern was aphthous like, followed by herpes-like lesions, candidiasis, glossitis/depapillation/geographic tongue, parotitis, and angular cheilitis. Oral lesions were more frequent in the tongue, lips, and palate, presenting miscellaneous clinical aspects that are more likely to represent coinfections. Therefore, the reanalysis of current evidence suggests the triad xerostomia, taste dysfunction, and oral mucosal lesions as common manifestations in patients with COVID-19. However, these outcomes are under discussion, and more studies will be necessary to confirm their association with direct SARS-CoV-2 infection in the oral cavity.
Oral Manifestations in Patients with COVID-19: A 6-Month Update.