There is currently no test available to identify whether an oral ulcer is classified as “aphthae” or not. People suffering from recurring aphthous stomatitis with scarring or persisting canker sores should consult a doctor to rule out other pathologies such as:
People with a canker sore persisting over a month should consult a doctor.
Recurrent aphthous stomatitis (RAS) is diagnosed whenever numerous canker sores evolving by crisis last 3 to 10 days, at least twice a year. Frequency and importance of these crises can require a preventive treatment because of the effects of the RAS on the daily life of the patient (difficulties in eating, pain, psychological effect).