Most mouth sores are cold sores (also called fever blisters), canker sores, or other irritation caused by:
Cold sores are caused by the herpes simplex virus and are very contagious. Usually, you will have tenderness, tingling, or burning before the actual sore appears. Cold sores usually begin as blisters and then crust over.
The herpes virus can live in your body for years. It only appears as a mouth sore when something triggers it, such as:
Canker sores are NOT contagious. They can appear as a single pale or yellow ulcer with a red outer ring, or as a cluster of these sores. The cause of canker sores is not clear, but may be related to:
For unknown reasons, women seem to get canker sores more often than men. This may be related to hormone changes.
Less commonly, mouth sores can be a sign of an illness, tumor, or reaction to a medication. Such illnesses can be grouped into several broad categories:
Drugs that may cause mouth sores include:
Mouth sores usually go away in 10 to 14 days, even if you don't do anything. They sometimes last up to 6 weeks. The following steps can make you feel better:
For canker sores:
Nonprescription medications, such as Orabase, can protect a sore inside the lip and on the gums. Blistex or Campho-Phenique may provide some relief of canker sores and fever blisters, especially if applied when the sore first appears.
To help cold sores or fever blisters, you can also apply ice to the sore.
Your doctor may recommend antiviral medications for herpes sores of the mouth. Some experts believe they make the blisters go away sooner, while others claim that these drugs make no difference.
Call your doctor if:
Your doctor will perform a physical examination, focusing on your mouth and tongue. Medical history questions may include the following:
Treatment may depend on the cause of the mouth sore.
You can reduce your chance of getting common mouth sores by:
You can avoid irritation by:
If you seem to get canker sores often, talk to your doctor about taking folate and vitamin B12 to prevent outbreaks.
To prevent the spread of herpes sores, do not kiss or have oral sex with someone who has a cold sore or fever blister. Do not participate in these activities when you have an active cold sore. Do not share razors, lip balm, toothbrushes, or lipsticks.
To prevent cancerous mouth sores:
Daniels TE. Diseases of the mouth and salivary glands. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 451.
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