Black hairy tongue (BHT, also termed lingua villosa nigra). BHT refers to a condition of the tongue where the filiform papillae elongate with black or brown discoloration, giving a black and hairy appearance. The appearance may be alarming, but it is a harmless condition.
Predisposing factors include smoking, xerostomia (dry mouth), soft diet, poor oral hygiene and certain medications (e.g., Tetracyclines).
Signs and Symptoms: Hairy tongue largely occurs in the central part of the dorsal tongue, just anterior (in front) of the circumvallate papillae, although sometimes the entire dorsal surface may be involved. Patients may experience a gagging sensation or a bad taste. There may also be associated oral malodour (intra- oral halitosis).
Treatment: Management is by improving oral hygiene, especially scraping or brushing the tongue. Keratolytic agents (chemicals to remove keratin) such as podophyllin are successful.