|Classification and external resources|
Geographic tongue is an inflammatory condition of the tongue affecting approximately 2% of the population as of 2003, and 3% of as 2012. It is characterized by discolored regions of taste buds or sometimes even cracks in the surface of the tongue. The condition is usually chronic, and frequently manifests after eating any of a range of exacerbating foods, or during times of stress, illness, or hormonal surges (particularly in women just before menstruating). It is also known as benign migratory glossitis, oral erythema migrans, glossitis areata exfoliativa, glossitis areata migrans, lingua geographica, stomatitis areata migrans, and transitory benign plaques of the tongue.:800
The top side of the tongue is covered in small protrusions called papillae. In a tongue affected by geographic tongue, red patches on the surface of the tongue are bordered by grayish white. The papillae are missing from the reddish areas and overcrowded in the grayish white borders. Whitish/yellow discoloration of the tongue is frequently due to a yeast infection. The small patches may disappear and reappear in a short period of time (hours or days), and change in shape or size. While it is not common for the condition to cause pain, it may cause a burning or stinging sensation, especially after contact with certain foods. Foods that sometimes cause irritation, burning or slight swelling of the tongue include tomato, eggplant, walnuts, sharp cheeses, spicy foods, sour foods, mint, candy and citrus. Coincidentally, most of these foods contain high levels of natural salicylates, e.g. 2.39 mg/100 g in oranges, 9.4 mg/100 g in fresh mint, and 218 mg/100 g in curry powder. Geographic tongue may also cause numbness. Coexistence of fissures of the tongue is often noticed. Chemicals, such as mouth washes and teeth whiteners, can also aggravate the condition. Lesions may occasionally occur on sites other than the tongue in the condition areata migrans. Lesions that are histologically indistinguishable from geographic tongue may also be diagnosed in Reiter's syndrome.
Ectopic geographic tongue 
Aside from occurring on the dorsal and lateral tongue, lesions infrequently involve the ventral tongue and buccal or labial mucosa. They are rarely reported on the soft palate and floor of the mouth. This condition is called migratory stomatitis or ectopic geographic tongue.
Irregular areas of dekeratinized and desquamated filiform papillae (red in color) are surrounded by elevated whitish or yellow margins due to acantholysis and hyperkeratosis. Neutrophils migrate into the epithelial layer, creating what are termed Munro's abscesses.
Its cause is uncertain, and can occur at any age though it tends to affect middle-aged to older adults and run in families and is associated with several different genes, though studies show family association may also be caused by similar diets. Geographic tongue is more commonly found in people or family history who are affected by environmental sensitivity, such as hay fever, pernicious anemia, eczema, and asthma. Lithium carbonate has been associated with the development of geographic tongue. There is a fourfold increase of geographic tongue with patients who have juvenile diabetes and this is possibly due to a increment of elevated amounts of HLA-B15 tissue type. Some think that it may be linked to stress or diets high in sugar or processed foods. Its prevalence also varies by nationality (0.6% of Americans, 4% of young Iraqis, 2% of young Finns) and gender (females are affected three times more than males). Causes vary, but may include zinc or vitamin B deficiencies, allergies, and hormonal changes. Geographic tongue is said to occur more often in women, especially folic acid deficiency during high hormonal times such as during ovulation or pregnancy, and while taking birth control (generally around the 17th day).[medical citation needed] Geographic tongue is commonly seen in children under the age of four but is not uncommon for older children.
Studies show there is a link between geographic tongue and psoriasis. Although geographic tongue is common in psoriasis, 90% of children who are diagnosed with geographic tongue do not contract psoriasis.
The New England Journal of Medicine reports a connection between Celiac Disease and geographic tongue and calls this association "very common." "Our report should alert physicians and dental practitioners to consider celiac disease in managing cases of idiopathic atrophic glossitis." 
Treatment is generally unnecessary  and will usually go away but may affect another area of the tongue. While there is no known cure or commonly prescribed treatment for geographic tongue, there are several ways to suppress the condition, including avoiding foods that exacerbate the problem. Steroid ointment, such as cortisone products, may be applied topically for symptomatic patients. Triamcinolone Acetonide Dental Paste USP,0.1% can be applied to affected area at night to try and help. Burning may also be reduced by antihistamines. The condition is usually asymptomatic and insignificant; persistent pain is rare. Varying in the severity, doctors and dentists may prescribe anesthetic mouth rinses, pain relievers or zinc supplements.
Geographic tongue is not contagious.
See also 
- Ship, Jonathan A.; Joan Phelan, and A. Ross Kerr (2003). "Chapter 112: Biology and Pathology of the Oral Mucosa". In Freedberg et al. Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. p. 1208. ISBN 0-07-138067-1.
- Mangione, Salvatore (2012). Physical Diagnosis Secrets: With STUDENT CONSULT Online Access. Elsevier. pp. 604–605. ISBN 0323112110. Retrieved November 12, 2012.
- James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: Clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
- Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0.
- Desai, A. B.; Vishwanathan, J. (1989). Textbook Of Paediatrics. India: Orient Blackswan. p. 405. ISBN 8125004408. Retrieved November 12, 2012.
- Burket, Lester William; Greenberg, Martin S.; Glick, Michael (2003). Burket's Oral Medicine: Diagnosis & Treatment. PMPH-USA. p. 116. ISBN 1550091867. Retrieved November 12, 2012.
- Zadik Y, Drucker S, Pallmon S (Aug 2011). "Migratory stomatitis (ectopic geographic tongue) on the floor of the mouth" (PDF). J Am Acad Dermatol 65 (2): 459–60. doi:10.1016/j.jaad.2010.04.016. PMID 21763590.
- Cameron, Peter; Jelinek, George; Everitt, Ian (2006). Tratado de Medicina de Urgencias Pediátricas. Elsevier. p. 365. ISBN 0443073481. Retrieved November 12, 2012.
- "Tongue, Geographic". webmd.com. Retrieved 2012-11-14.
- "Geographic Tongue: Causes and Treatments". webmd.com. Retrieved 2012-11-14.
- Hechtman, Leah (2012). Clinical Naturopathic Medicine. Elsevier. p. 1511. ISBN 0729541517. Retrieved November 12, 2012.
- USA (2010-12-08). "Geographic tongue (migrant glossitis) and psoriasis". Minerva Stomatol 50 (6): 213–7. PMID 11535977.
- Migratory Glossitis (Geographic Tongue).
- Alberta Lucchese, Agostino Guida, Rosario Serpico. (2012) Glossodynia and coeliac disease. Immunopharmacology and Immunotoxicology 1-3 Atrophic Glossitis Leading to the Diagnosis of Celiac Disease.
- http://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_artikkeli=dlk00780. Missing or empty
- Burkhart, Nancy W. "Geographic Tongue". PennWell. Retrieved 2012-11-14.
- Shulman J. D. Prevalence of oral mucosal lesions in children and youths in the USA. Int J Paediatr Dent. Mar 2005;15(2):89-97.
- Kleinman D. V., Swango PA, Pindborg JJ. Epidemiology of oral mucosal lesions in United States schoolchildren: 1986-87. Community Dent Oral Epidemiol. Aug 1994;22(4):243-53.
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