Background Oral aphthous stomatitis is a common lesion and frequency is reported between 10-20% in the community. Although the exact etiology is unknown; immunological, allergic, nutritional and microbial factors, certain medications and some chronic/rheumatic diseases are associated.

Objectives The present population-based epidemiological study aimed to determine the frequency of recurrent aphthous stomatitis (RAS) and associated factors.

Methods In 2013, a cohort for chronic diseases and related risk factors was initiated by the Turkish Society of Internal Medicine. For this purpose, Avanos and Gülşehir counties, which have a 5-year migration rate of less than 10%, were selected among the county seats of the Central Anatolia Region of Turkey (Cappadocia region). The cohort consisted of subjects aged ≥18 years living in the relevant counties and it was targeted to reach whole adult population. Informed consents were obtained from the adults and 90% of whole adult population agreed to participate in the study. Photos showing oral aphthous were usedwhen applying the questionnaire for chronic diseases. Participants with and without oral aphthous ulcer were compared in terms of sociodemographic and medical characteristics.

Results Data of 11,049 participants (mean age, 44.6±16.4 years; 56.1% males) were evaluated. Of the participants, 13.2% had RAS (Female/Male: 17.1/8.2%). In logistic regression analysis female gender (p<0.001; OR =1.441±1.253-1.656), any rheumatic disease presence (p=0.001; OR =2.364±1.408-3.968), history of joint swelling (p<0.001; OR =1.755±1.527-2.016), presence of low back pain, (p<0.001; OR =1.727±1.529-1.952) were found to be independent risk factors for RAS development. Age (p=0.001; OR =0.994±0.990-0.997), alcohol usage (p=0.033; OR =0.744±0.566-0.977) and smoking (p<0.001; OR =0.651±0.555-0.763) were found to be protective factors.

Conclusions In our cohort, RAS prevalence was found to be 13.2%. Advanced age and smoking are known to reduce development of RAS, as well as alcohol usage may have role of reducing development of RAS. People with RAS should be evaluated for underlying chronic and rheumatic diseases.

Acknowledgements The present study was unconditionally funded by the Turkish Society of Internal Medicine, which provided financial support for data collection and analysis and manuscript preparation. The Turkish Society of Internal Medicine had no contribution to the study design and interpretation of the results. The authors declare no conflict of interests.

Disclosure of Interest None declared