Merck Manual

Please confirm that you are a health care professional

honeypot link

Tongue Discoloration and Other Changes


Bernard J. Hennessy

, DDS, Texas A&M University, College of Dentistry

Last full review/revision May 2020| Content last modified May 2020
Click here for Patient Education
Topic Resources

The tongue may undergo changes in color and surface. Changes may be focal or involve most of the tongue. Some changes are asymptomatic; others cause tongue discomfort.

Tongue color changes

The papillary surface (dorsum) of the tongue may become discolored by smoking or chewing tobacco, consuming certain foods or vitamins, or by surface growth of pigmented bacteria.

Black discoloration on the dorsum may be due to oral bismuth preparations. Brushing the tongue with a toothbrush or scraping it with a tongue scraper may remove such discoloration.

Blue-black discoloration, focal, small, and unchanging, on the ventral surface, may be an amalgam tattoo.

A pale, smooth tongue can be caused by atrophic glossitis, which can occur with iron deficiency or vitamin B12 deficiency.

Magenta tongue suggests vitamin B12 deficiency.

A strawberry-red tongue may be the first sign of scarlet fever or, in a young child, a sign of Kawasaki disease.

A smooth red tongue and painful mouth may indicate general inflammation of the tongue (glossitis) or be caused by niacin deficiency.

Tongue surface changes

The most common tongue surface changes, which are benign, are

  • Geographic tongue (benign migratory glossitis, or erythema migrans)

  • Fissured tongue (often associated with geographic tongue)

  • Hairy tongue

In geographic tongue, areas of the tongue are red and smooth (due to atrophy of filiform papilla) and are often surrounded by a slightly elevated yellow-white border. Other areas may be white or yellow and rough, representing psoriaform changes or coexisting psoriasis itself. The areas of discoloration can migrate over a period of weeks to years. The condition is usually painless, and no treatment is needed. If people have symptoms, applying low doses of corticosteroid sometimes helps.

Tongue Surface Changes

Fissured tongue is an idiopathic condition usually occurring in about 5% of adults in the US (and in up to 30% of older adults). Deep grooves are located either along the midline or are distributed over the dorsum. Fissured tongue may occur with geographic tongue, Down syndrome, or Melkersson-Rosenthal syndrome, a rare syndrome that also features facial palsy and granulomatous cheilitis.

Hairy tongue is due to accumulation of keratin on normal filiform papillae that gives the tongue a hairy appearance. Hairy tongue is caused by lack of mechanical stimulation to the tongue (eg, due to poor oral hygiene) with trapping of residual food debris among the papillae. Hairy tongue may also appear after a fever, antibiotic treatment, or with excessive use of peroxide mouthwash. It is common in heavy smokers. Hairy tongue should not be confused with hairy leukoplakia, which usually is associated with immunodeficiency (especially HIV infection) and appears as white, hairy-appearing patches on the side of the tongue.

Tongue lesions

The tongue may develop focal lesions or discoloration.

Tongue ulcers may be herpetiform aphthous ulcers (ventral tongue surface) or be due to trauma from accidental biting or from rubbing against a fractured tooth or restoration.

Whitish patches on the tongue, similar to those sometimes found inside the cheeks, may accompany

  • Fever

  • Dehydration

  • Secondary syphilis

  • Oral candidiasis (thrush)

  • Lichen planus

  • Leukoplakia

  • Mouth breathing

Changes in the Mouth and Tongue

Red patches on the tongue may indicate

  • Erythroplakia

  • Atrophic glossitis related to pernicious anemia

  • Median rhomboid glossitis

  • Traumatic ulcer from accidental biting or rubbing against sharp tooth or restoration.

Leukoplakia and erythroplakia may be manifestations of oral squamous cell carcinoma.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Test your knowledge

Lips Sores and Inflammation
Several infectious, malignant, or premalignant conditions can cause lip sores. Of these conditions, which of the following presents as multiple bullae that rupture quickly and leave crusting hemorrhagic ulcers on the labial mucosa?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest