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Aphthous stomatitis

Last updated: January 3, 2021


Aphthous stomatitis (also known as canker sores) is characterized by frequent recurrent mouth ulcers. The cause of these painful, mostly benign sores is unknown, but they commonly occur after minimal trauma (e.g., biting the tongue). There are several types of aphthae, all of which can only be treated symptomatically.


  • Very frequent


Epidemiological data refers to the US, unless otherwise specified.



Clinical features

  • Painful mucosal ulcers in nonkeratinized areas of the mouth and throat
  • Recurrence is common
  • No systemic symptoms
  • Efflorescence: round to oval, crater-like appearance on yellowish-grey base and erythematous margins


Differential diagnoses

See “Differential diagnosis” in acute tonsillitis

The differential diagnoses listed here are not exhaustive.




  • Benign, often recurrent
  • If ulcers persist for longer than 6 weeks, test should be conducted to rule out the possibility of malignancy.


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  2. Goldstein BG, Goldstein AO, Dellavalle RP, Deschler DG, Corona R. Oral Lesions. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/oral-lesions.Last updated: January 30, 2017. Accessed: June 24, 2017.
  3. Scully C, Meyers AD. Aphthous Ulcers. Aphthous Ulcers. New York, NY: WebMD. http://emedicine.medscape.com/article/867080-overview. Updated: January 20, 2017. Accessed: June 24, 2017.
  4. Eichenfield LF, Frieden IJ, Zaenglein A, Mathes E. Neonatal and Infant Dermatology E-Book. Elsevier Health Sciences ; 2014