Canker sores are small, painful lesions that form on the soft tissues in your mouth: the insides of your lips, cheeks, under your tongue or at the base of your gums.
What causes them?
The cause for canker sores isn't precisely established. They may be triggered by poor nutrition, stress, food alergies or menstrual periods.
How are they treated?
They usually go away by themselves. For the pain, you can take ibuprofen or acetaminophen (Advil and Tylenol). To prevent the irritation caused by eating, drinking or brushing your teeth you can use Anbesol, Orajel, Orabase and Zilactin-B. All these are applied directly on the sore.
When should I go seek help?
1. If they're large and they last longer than 2 weeks, or are painful enough that they keep you from eating and drinking.
2. If you have fever or feel sick while having them.
3. If you have them more than 3 times per year
How can my doctor help me?
He can prescribe an anti-inflammatory (Aphthasol or Kenalog in Orabase) or collagenase inhibitor (Tetracycline or Peridex).