Abnormality of the mouth Recurrent aphthous stomatitis 2011-06-08T07:11:09Z Recurrent aphthous ulcers Aphthous stomatitis UMLS:C0038363 SNOMEDCT_US:426965005 Recurrent episodes of ulceration of the oral mucosa, typically presenting as painful, sharply circumscribed fibrin-covered mucosal defects with a hyperemic border. Buccal aphthous ulcers UMLS:C2937365 SNOMEDCT_US:110426005 SNOMEDCT_US:427617000 Recurrent canker sores Recurrent aphthous stomatitis can be classified into three forms, with minor ulcers (over 80% of RAS cases) being less than 1 cm in diameter and self-limiting; major ulcers being over 1 cm in diameter with potential scar formation; and herpetiform ulcers manifesting as recurrent episodes with multiple small ulcers throughout the oral mucosa. HP:0011107 Recurrent oral aphthae SNOMEDCT_US:398870000 Increased inflammatory response