Worldwide prevalence of geographic tongue in adults: a systematic review and meta‐analysis

To identify the prevalence of geographic tongue in patients >18 years. A systematic literature review was performed in search of population-based observational studies. Searches were performed using five main databases: Embase, LILACS, PubMed, Scopus and Web of Science; and three gray literature sources: Google Scholar, ProQuest, and OpenGrey. In addition, a manual search in the reference list and consultation with experts on the topic studied were performed. Methodological quality was assessed using the Joanna Briggs Institute's checklist for prevalence studies. Ratio meta-analyses were performed using JAMOVI. Initially, 3046 studies were identified. After a two-phase selection, 11 studies were included for quantitative synthesis. Two studies were classified as of low methodological quality, five studies as of moderate quality, and four as of high quality. Two types of prevalence were analyzed: by period and point. Three studies were included in the period prevalence meta-analysis, and the prevalence was 3% (Confidence interval [CI]: 0.4%-5.5%, n = 9813). Eight studies were included in the point-prevalence meta-analysis, and the prevalence was 3% (CI: -0.2% to 5.5%, n = 10,967). Although there are phases of exacerbation and remission in geographic tongue, prevalence and period prevalence were similar. Approximately one in 30 adults has a geographic tongue.