Hairy tongue is a benign change of the top surface of the tongue that is characterized by elongation of the many small nodules called papillae. It gets is name because the papillae resemble stubby hairs. The papillae can become stained from coffee, tea, colored soda, or bacteria. The cause is unknown but it is usually seen during antibiotic use, in smokers, in persons using stomach antacids, or in hospitalized and/or debilitated patients. Usually it is asymptomatic but may produce bad breath or cause a burning sensation. Treatment is to scrape the tongue, which will remove the papilla but the condition can recur.
Fissured Tongue is a condition in which cracks or fissures are observed on the surface of the tongue. Food debris and some bacteria colonies may form in the fissures but this is almost always a condition with no symptoms. No treatment is necessary once it is properly diagnosed.
Geographic tongue gets its name from the map-like appearance on the surface or the tongue. This results from irregular, bare patches on its surface. The specific cause of geographic tongue is unknown, although it may occur due to irritation from hot or spicy foods, alcohol, or tobacco, or from allergies.
The pattern on the surface of your tongue may change very quickly. The pattern results from the loss of papillae. This gives areas of the tongue flat spots, and thus a geographic appearance. These areas of papillae loss are said to be denuded. The bare spots may last for more than a month but no treatment is usually necessary once it is properly diagnosed.