Brief ans: RECURRENT APTHOUS STOMATITIS/ RECURRENT CANKER SORES. Hi.. Can understand your concern.. As per your complain it seems that you have repeated episodes of canker sores. There is no known specific reason for the occurrence of canker sores and its recurrence and treatment is based on relieving the symptoms. If you have pain and discomfort application of numbing gels like Oragel or orabase gel or mucopain gel is helpful. In cases of severe inflammation steroid creams can also be applied.. Anti inflammatory and painkiller medicines like Ibuprofen can be taken. Keep your self well hydrated. Avoid hot and spicy foods. Take more of cold liquids. Taking multivitamins for a period of 15 days can be helpful. If you have any sexual exposure with infected partner which is causing you think that you have cold sores which is a viral infection caused by herpes simplex virus ,you are correct that the blisters caused by herpes virus commonly occur outside the mouth but can also occur inside the mouth commonly on gums and roof of mouth. In case of viral infection antiviral ointments can be applied on the sores . Antiviral medicines are of less value in this case as they do not cure the infection and can just prevent outbursts. You should avoid intimate contact with anyone as cold sores are contagious. But to get exact diagnosis you should see a doctor first for clinical check up. Hope your query is solved.. Thanks and regards.. Dr.Honey Nandwani Arora.