White Coated Tongue

Dr. Huma SadafBDS

September 19, 2019

April 21, 2021

White Coated Tongue
White Coated Tongue

What is it?

Tongue provides a glimpse of the overall health of an individual. Hence, doctors usually do a visual examination of the tongue during the initial checkup.

White coated tongue is a condition characterised by the development of a thick white or grey covering on the surface of the tongue. The coating could be food debris, bacterial colonies, dead cells deposits on the tongue or it might reflect some internal changes in the superficial cells of the tongue. It may either occur in patches - both big and small - or it may cover the entire tongue.

In most cases, a white-coated tongue is just an indication of poor oral hygiene. However, a white coat on the tongue is also associated with some health conditions like oral thrush and leukoplakia

What are the causes?

Human tongue has tiny projections - called papillae - coming out of its surface. These papillae give a rough texture to the tongue and are generally the same colour as the tongue. They are small enough to go unnoticed most of the time. However, when these papillae swell and enlarge, bacteria, fungi, dead cells and food debris get accumulated in between them. This is what causes the typical appearance of a white-coated tongue.

Accumulation of food and microbes gives rise to bad breath along with an increased probability of gum diseases.

Apart from deposits on the tongue surface, there are few other conditions which are strongly associated with white tongue, though the occurrence is rare, these include:

  • Leukoplakia: Leukoplakia is a potentially malignant lesion (can turn into cancer) manifested in the form of thick, raised white plaques on the oral mucosa (membrane lining the inner surface of mouth) and sometimes tongue. The white coat caused by leukoplakia can not be scraped manually because it is caused by pathological changes at the tissue level.
  • Oral lichen planus: It is an autoimmune condition that affects skin and mucosal lining. Lichen planus lesions appear as interlinked white threads which are slightly raised from the surface - also known as Wickham's striae. When the lesion develops on the tongue, it might appear as a white-coated tongue. However, oral lichen planus is also associated with mouth ulcers and inflamed gums.
  • Geographic tongue: It is an inflammatory condition of the tongue characterised by the atrophy of tongue papillae in a map-like pattern, hence the name. The atrophied areas appear red and smooth surrounded by white hyperkeratotic areas - caused due to increased deposition of keratin protein. The white lines of the geographic tongue are what make it look like a white-coated tongue.
  • Oral thrush or oral candidiasis:  Oral thrush is a fungal infection caused due to the growth of a yeast - Candida. When oral candidiasis involves the tongue, it causes deposition of white creamy plaques on the tongue surface.
  • Oral hairy leukoplakia: Oral hairy leukoplakia is an opportunistic infection that only affects immunocompromised patients, like, those with AIDS. It is a viral disease caused due to Epstein Barr virus and usually affects the border of the tongue. However, it can also involve the whole tongue surface. Clinically, oral hairy leukoplakia presents as velvety whitish plaque which cannot be scraped.

What are the signs and symptoms?

White coated tongue is not a disease in itself, it is a symptom that appears as white patches on the tongue surface. The associated signs and symptoms of a white-coated tongue depend on the underlying cause. Some of these include:

  • Bad breath (most common)
  • Bleeding after scraping tongue
  • Redness of tongue 
  • Tongue may feel thick 
  • Burning sensation of tongue

Diagnosis and treatment

For white-coated tongue, detailed patient history and clinical examination of the tongue is usually enough. The doctor will ask about your oral hygiene routine (brushing and flossing habits) and smoking or tobacco chewing habits. He/she will then examine the white coating to check if it is scrapable or not and to find other characteristic signs of possible causative diseases.

Although to look for internal changes in the tongue, histological examination can be done. Your doctor may take a small tissue sample from the tongue and send it to the laboratory for histopathological examination.

Once a diagnosis is made, the treatment is followed accordingly. In other words, the mode of treatment will depend on the cause.

If the white-coated tongue is due to poor oral hygiene, the dentist will do a thorough cleaning of your oral cavity and advice you to follow a proper oral hygiene routine.

In the case of leukoplakia, cessation of smoking or tobacco chewing usually reduces the symptoms. Some antioxidant supplements may be prescribed to promote healing.

Mild form of lichen planus resolves on its own, however, severe lesions are treated with local application of steroids or steroid pills.

For oral candidiasis, antifungal ointments and drugs are the mainstay treatment.


  1. Hamed Mortazavi et al. Oral White Lesions: An Updated Clinical Diagnostic Decision Tree . Dent J (Basel). 2019 Mar; 7(1): 15. PMID: 30736423
  2. Alessandro Villa, Sook Bin Woo. Leukoplakia—A Diagnostic and Management Algorithm . Journal of Oral and Maxillofacial Surgery; April 2017, Volume 75, Issue 4, Pages 723–734
  3. Cleveland Clinic. [Internet]. Cleveland, Ohio. White Tongue
  4. American Academy of Oral Medicine, Seattle. Oral Lichen Planus. [internet]
  5. Bruna Lavinas Sayed Picciani et al. Geographic tongue and psoriasis: clinical, histopathological, immunohistochemical and genetic correlation - a literature review. An Bras Dermatol. 2016 Jul-Aug; 91(4): 410–421. PMID: 27579734
  6. National Health Service [Internet]. UK; Sore or white tongue.