Black Hairy Tongue

Black hairy tongue, also known as lingua villosa nigra, is a painless, benign disorder caused by defective desquamation and reactive hypertrophy of the filiform papillae of the tongue. The hairy appearance is due to elongation of keratinized filiform papillae, which may have different colors, varying from white to yellowish brown to black depending on extrinsic factors (eg, tobacco, coffee, tea, food) and intrinsic factors (ie, chromogenic organisms in normal flora).