Canker sores

Aphthous ulcer
A canker sore (aphthous ulcer) is a common form of mouth ulcer. It is a benign open sore in the mouth, which appears as a painful white or yellow sore (ulcer) surrounded by a bright red area. The cause is unknown.
There may be an inherited predisposition to their development. There may also be an immune system link. Ulcers may develop in response to mouth injury such as dental procedures or aggressive tooth cleaning. They are also triggered by stress, dietary deficiencies (especially iron, folic acid, or vitamin B12), menstrual periods, hormonal changes, food allergies, and similar situations. They may occur with no identifiable cause. Canker sores usually appear on nonkeratinized mouth tissue including the inner surface of the cheeks and lips, tongue, soft palate, and the base of the gums. They usually begin with a tingling or burning sensation, followed by a red spot or bump that ulcerates. Pain spontaneously decreases in 7 to 10 days, with complete healing in 1 to 3 weeks. Occasionally, a severe occurrence may be accompanied by nonspecific symptoms of illness such as fever or malaise. Recurrence is common and may continue for years.
Canker sores occur in women more often than men. They may occur at any age, but usually first appear between the ages of 10 and 40.
(G) Very specific problems