Black hairy tongue (BHT) represents a benign reactive process characterized by hyperplasia and dark pigmentation of the tongue’s filiform papillae. The elongated filiform papillae may reach up to 2 cm in length and vary in actual degree of pigmentation from light tan to black. Predisposing factors include excessive smoking, gastroesophageal reflux, poor oral hygiene, chemotherapy, and the use of broad-spectrum oral antibiotics. Pigment from consumed food, beverages, and tobacco products stains the entrapped food debris and desquamated papillary keratin. Some antibiotics may alter normal oral microflora and promote the growth of chromogenic organisms, also contributing to the tongue’s discoloration. The darkly pigmented filament-like papillae give the tongue a black, hairy appearance. Males are more often affected than females; this condition very rarely occurs in children. Patients with BHT frequently note alterations of taste perception and fetid breath.
Geographic tongue and orolingual candidiasis may resemble more lightly pigmented forms of BHT. Similarly, dark discoloration of normal tongue papillae may also mimic BHT. This exogenous pigmentation of normal papillae may come from ingested food dyes and certain medications, such as bismuth-containing compounds, ketoconazole, and azidothymidine. The lack of hyperplastic filiform papillae with additional pigmentation of other oral mucosal surfaces may aid in distinguishing these conditions.
Black Hairy Tongue. Hyperplasia of the filiform papillae on the dorsum of the tongue accompanied by deposition of dark pigment is characteristic of black hairy tongue. (Photo contributor: Department of Dermatology, National Naval Medical Center, Bethesda, MD.)
Management and Disposition
Improved oral hygiene with gentle tongue brushing and a reduction in the ingestion of exogenous pigment-containing substance represent the cornerstones of treatment. Removal of other predisposing factors (eg, antibiotic withdrawal and smoking cessation) will also promote resolution of this condition. The use of topically applied retinoid preparations and antifungal agents has been advocated for more refractory instances.
BHT involves the superior aspect of the tongue.
The tongue is not always black and can be a tan or yellow color.
Black Hairy Tongue. Deposition of black pigment secondary to bismuth ingestion. This patient ingested Pepto-Bismol. (Photo contributor: Kevin J. Knoop, MD, MS.)