All the patients who are ready to participate in the study will receive from their physician the cell phone number of the Nose Throat and Ear physician (G.Z.) and the physician will ask the patient to contact G.Z. when they have a canker sore. In addition the patient's physician will also give the patient a written health synopsis, which will include any chronic diseases, sensitivity to medication and medical treatment. The patient will give this synopsis to one of the investigators ((IV, YP, RP, IR,) when they meet with him. The patient will then contact G.Z. and will be examined by him within 48 hours after the canker sore(s) appear to ascertain that the condition is actually recurrent aphthous stomatitis.