You may need further testing or a biopsy to look for other causes of mouth ulcers. Canker sores are not cancer and do not cause cancer. There are types of cancer, however, that may first appear as a mouth ulcer that does not heal.
In most cases, the canker sores go away without treatment.
Try not to eat hot or spicy foods, which can cause pain.
Use over-the-counter medicines that ease pain in the area.
Rinse your mouth with salt water or mild, over-the-counter mouthwashes. (DO NOT use mouthwashes that contain alcohol which can irritate the area more.)
Apply a mixture of half hydrogen peroxide and half water directly to the sore using a cotton swab. Follow by dabbing a small amount of Milk of Magnesia on the canker sore afterward. Repeat these steps 3 to 4 times a day.
Rinse your mouth with a mixture of half Milk of Magnesia and half Benadryl liquid allergy medicine. Swish mixture in the mouth for about 1 minute and then spit out.
Medicines prescribed by your provider may be needed for severe cases. These may include:
Stronger medicines called corticosteroids that are placed on the sore or are taken in pill form
Brush your teeth twice a day and floss your teeth every day. Also, get routine dental check-ups.
Canker sores almost always heal on their own. The pain should decrease in a few days. Other symptoms disappear in 10 to 14 days.
When to Contact a Medical Professional
Call your provider if:
A canker sore or mouth ulcer does not go away after 2 weeks of home care or gets worse.
You get canker sores more than 2 or 3 times a year.
You have symptoms with the canker sore such as fever, diarrhea, headache, or skin rash.
Daniels TE, Jordan RC. Diseases of the mouth and salivary glands In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 425.
Sumana Jothi MD, Otolaryngology-Head and Neck Surgery, Airway, Voice, and Swallowing Disorders, Clinical Instructor UCSF Otolaryngology, NCHCS VA, SFVA, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.