Hairy tongue, also known as black tongue, refers to an accumulation of keratin on the tips of the filiform papillae of the dorsal tongue. This results in a hair-like appearance of the dorsal tongue. While wet, keratin normally appears white, black, brown, or yellow, the discoloration due to exogenous pigmentation caused by colored foods or drinks; colonization of the keratin by pigment-producing bacteria is often seen.
Keratin is constantly produced by the dorsal tongue papillae, and in the normal situation, the rate at which the keratin is produced is equal to the rate at which it is debrided by normal mechanical actions of chewing and swallowing foods. Anything that disturbs that balance will result in coated or hairy tongue:
Increased production of keratin can be seen with any irritant, including cigarette smoking, continuous exposure to hot beverages, or excessive brushing of the dorsal tongue.
Antibiotics, corticosteroids, and antipsychotics are the most common triggering medications.
Decreased debridement is seen in patients who are edentulous (or have complete dentures) or have chronic hyposalivation for any reason, either of which can cause the patient to select a soft or more liquid diet.
Patients who have a chronic illness that results in decreased food intake frequently develop a coated or hairy tongue as well.
The patient is often asymptomatic and may be more concerned about the appearance of the tongue. Occasionally, the patient may report a stale taste or malodor. The gag reflex may be triggered if the hairy tongue is posteriorly located and tickles the palate. While some make a distinction between hairy tongue and coated tongue, they are essentially the same process.
ICD10CM: K14.3 – Hypertrophy of tongue papillae
SNOMEDCT: 81934005 – Hairy tongue
Differential Diagnosis & Pitfalls
Candidiasis – This is the most common misconception related to hairy tongue. Most chronic candidal infections of the dorsal tongue are seen as an asymptomatic symmetrical erythematous atrophic area in the midline posterior (see median rhomboid glossitis).
Hairy leukoplakia (Epstein-Barr virus infection) – Usually seen in immunocompromised patients, this tends to affect the lateral borders of the tongue bilaterally; infrequently, this condition may extend onto the dorsum. Like hairy tongue, it is asymptomatic. The histopathologic features are suggestive, and identification of EBV in the lesion is diagnostic.
Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
Hairy tongue, also known as black tongue, is a benign condition of elongation and staining of the fingerlike projections (papillae) on the tongue surface. This condition may be caused by overgrowth of a bacteria or yeast that produces a colored substance (pigment). Anything that reduces the flow of saliva in the mouth, such as dehydration or illness, or if the person is not eating a normal diet, can lead to the condition, which typically develops over a few weeks. Medications that commonly cause hairy tongue include antibiotics, anti-psychotics, anti-depressants, and anti-cholinergic agents. Other causes include smoking, alcohol, the use of mouthwashes, and exposure to radiation therapy.
Who’s At Risk
Hairy tongue can occur at any age, but it is most common in people who are dehydrated, ill, or not eating a normal diet. People taking certain medications or with certain exposures may also be more susceptible.
Signs & Symptoms
Hairy tongue most commonly affects the front two thirds of the tongue surface (not underneath the tongue). The tongue may be yellow, orange, green, brown, or black, with a coated, rough, or "hairy" look. You may notice a stale taste or smell in the mouth and a more sensitive gag reflex, but it is painless.
Gently brush the tongue with a toothbrush twice daily. Then rinse the mouth with a dilute solution of hydrogen peroxide (1 part peroxide to 5 parts water), or apply the solution with a toothbrush. Rinse the mouth with plain water.
Maintain good oral hygiene with regular tooth brushing.
Minimize mouthwash use and avoid smoking or chewing tobacco.
Eat more foods with fiber (fruits and vegetables); sucking on pieces of fresh pineapple may also be helpful.
When to Seek Medical Care
If self-care measures are unsuccessful, seek medical advice.
A scraping or biopsy might be recommended. Sometimes an antibiotic or antifungal medication will be prescribed.
Bolognia, Jean L., ed. Dermatology, pp.1080-1081. New York: Mosby, 2003.