parasitic glossitis, a mycosis of the tongue, characterized by a black or brown furry patch on the posterior dorsal surface. The patch is composed of hypertrophied filiform papillae that measure about 1 cm in length and are easily broken. This condition may occur as the result of poor oral hygiene, the use of broad-spectrum antibiotics, or radiation treatment of the neck and head. The condition, caused by Cryptococcus linguae-pilosasae in symbiosis with Nocardia lingualis, produces no discomfort and may be treated with a simple mouthwash. The patch may disappear spontaneously and later reappear. Also called black hairy tongue, glossitis parasitica, glossophytia.
