What Causes a Black Colored Tongue?

Patient Presentation
A 14-year-old caucasian male came to clinic because he had noticed his tongue becoming darker over the previous week. He was very concerned about the coloring as he said it would not go away. He was studying for school examinations and had been self-medicating an upset stomach with Pepto-Bismol®. About 1 month ago he was diagnosed with bronchitis at an urgent care center and had taken antibiotics. The past medical history was negative except for being overweight. The review of systems was negative. The pertinent physical exam showed a well-appearing male whose BMI was 28.9 with normal vital signs. HEENT showed poor oral hygiene with obvious caries. He had dark brown coloring of the top of the tongue anteriorly, not involving the sides, that was uniform. Scraping appeared to decrease the discoloration but it didn’t completely go away. There was no elevation of the tongue nor oral masses visible or palpable. There were some shoddy anterior cervical nodes. His neck had a normal thyroid examination and no masses. Skin examination showed acne on his face, and a few brown macules and freckles scattered on his trunk, arms and face that he reported to be unchanged. He had no discoloration of the palms or soles. The diagnosis of poor oral hygiene along with taking bismuth was made. He was counseled about the bismuth use and school stress. He was also counseled about oral hygiene including scraping of his tongue. Followup at 1 month showed that the discoloration had resolved and his stress after examinations.

Discussion
Although dental caries, strep throat and oral candidiasis are some of the most common oral pathology. The tongue itself can be a source of potential pathology. Geographic tongue, oral candidiasis, and lingual ulcerations are common problems. Most discolorations of the tongue are because of food, drink or medications that are ingested and are self-limited. However discoloration can be a sign of more significant problems.
Hairy tongue, often colored black, is a relatively uncommon problem in the US but has a higher incidence reported in Turkey and Iran. It is more common in adults than children but has been reported in a child 2 months of age. It is also called lingua villosa nigra and is a benign condition caused by keratin accumulation usually in the setting of poor oral hygiene and/or xerostomia. The accumulation is on the filliform papillae and will be seen on the dorsal surface anterior to the circumvallate papillae and not on the lateral sides of the tongue or tip. The discoloration can be different colors depending on the oral flora. Hairy tongue usually responds to oral hygiene including scraping of the tongue, but sometimes retinoids, keratolytic agents and other treatments are used.

Learning Point
The differential diagnosis of a black tongue includes:

  • Normal variation
  • Poor oral hygiene
  • Acanthosis nigracans
  • Adrenal insufficiency
  • Congenital lingual melanotic macules
  • Congenital melanocytic naevi
  • Drugs
    • Antibiotics use
    • Linzezold
    • Minocycline
    • Graft vs. Host Disease
    • Heavy metals
    • Infection
      • Candida
      • Kocuria (Micrococcus) kristinae
    • Lingua villosa nigra “Black hairy tongue”
    • Lupus (possibly associated)
    • Neurofibromatosis
    • Oncological
      • Melanoma
      • Post-radiation
    • Peutz Jegher
    • Staining
      • Bismuth
      • Food coloring including coffee, tea
      • Smoking

    Questions for Further Discussion
    1. What is the differential diagnosis of white lesions in the mouth?
    2. What are the indications for referral for discoloration of the tongue and to whom would you refer?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Tongue Disorders

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    McGrath EE, Bardsley P, Basran G. Black hairy tongue: what is your call? CMAJ. 2008 Apr 22;178(9):1137-8.

    Akl KF. Black tongue. J Paediatr Child Health. 2009 Jan-Feb;45(1-2):73-4.

    Akay BN, Sanli H, Topcuoglu P, Zincircioglu G, Gurgan C, Heper AO. Black hairy tongue after allogeneic stem cell transplantation: an unrecognized cutaneous presentation of graft-versus-host disease. Transplant Proc. 2010 Dec;42(10):4603-7.

    Thompson DF, Kessler TL. Drug-induced black hairy tongue. Pharmacotherapy. 2010 Jun;30(6):585-93.

    Nisa L, Giger R. Black hairy tongue. Am J Med. 2011 Sep;124(9):816-7.

    Oncel EK, Boyraz MS, Kara A. Black tongue associated with Kocuria (Micrococcus) kristinae bacteremia in a 4-month-old infant. Eur J Pediatr. 2011 Sep 21.

    Guinovart RM, Carrascosa JM, Bielsa I, Rodriguez C, Ferrandiz C. A black tongue in a young woman. Clin Exp Dermatol. 2011 Jun;36(4):429-30.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    8. Health care services aimed at preventing health problems or maintaining health are provided.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.
    18. Using effective nonverbal, explanatory, questioning, and writing skills, the healthcare professional uses effective listening skills and elicits and provides information.
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital