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Canker sore (aphthous ulcer)

Canker sore (aphthous ulcer)

Overview

Canker sores (Aphthous ulcers) are very common. Typically, they are a shallow ulcer with a white or whitish/yellow base surrounded by a reddish border. This severe form of ulcer can be seen in an individual with AIDS and is located in front and just below the bottom teeth.

Review Date 4/3/2025

Updated by: Ashutosh Kacker, MD, FACS, Professor of Clinical Otolaryngology, Weill Cornell Medical College, and Attending Otolaryngologist, New York-Presbyterian Hospital, New York, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.