A geographic tongue causes stinging or burning sensations and occasionally causes pain, swelling or numbness. Geographic tongue alters papillae–small protrusions on which taste buds are located–that are evenly spread out on unaffected tongues. Close examination shows red patches with grayish-white borders on the surface of the geographic tongue. Papillae are missing within the red patches, but clustered in the gray areas. Foods and beverages precipitate symptoms that disappear and reappear, changing in shape or size within hours or days. This condition runs in families, but the true cause of the condition is uncertain.
While there are no known cures for a geographic tongue, you can inhibit symptoms and alleviate discomfort by avoiding foods that may aggravate the condition. Acidic fruits are common triggers for geographic tongue flare-ups, with citrus fruits, tomatoes and pineapples causing the worst reactions in the fruit category.
Although the appearance of a geographic tongue may be unfamiliar and possibly disturbing, it doesn't cause health problems and is not associated with infections or cancer. However, if sores develop on your tongue or in another part of your mouth, consult with an oral health care provider.
Many people who have a geographic tongue do not experience pain or loss of taste. They do feel occasional irritation in affected spots on the tongue or increased sensitivity and discomfort when eating certain foods. Hot, spicy foods and sauces, especially those containing chili peppers or chili powder, are prime causes of symptoms.
Geographic tongue is also known as benign migratory glossitis, which means that it is a non-malignant, non-invasive inflammation of the tongue with patches or lesions that heal in one part of the tongue and then migrate or move to another.
These patches on the tongue have a map-like or geographic pattern. Walnuts cause inflammation, stinging and sometimes pain when eaten by someone who has a geographic tongue. Pecans can have a similar, but less extreme effect.
Vegetables that can provoke a reaction on the tongue are eggplant, chard and spinach. Raw spinach is less problematic than cooked spinach. People suffering from geographic tongue may also have a fissured tongue, a disorder that causes deep fissures or grooves on the surface of the tongue. Cooked spinach seems to enter the grooves of a geographic tongue and act as an irritant, causing swelling and discomfort for some people.
The patterns on the surface of a geographic tongue can change quickly and this happens when a food or substance affects the tongue's papillae and renders them flat rather than protruding. These areas are described as "denuded" and the denuded spots can persist for months, making the tongue more sensitive. Foods that cause this to happen include strong cheeses, such as those in the bleu or Swiss cheese families; oregano, the seasoning used in tomato sauces and on fish or poultry; and strongly flavored candies, such as peppermint or cinnamon hard candy.