A Case of Lingua Villosa Nigra (Black Hairy Tongue) in a 3-Month-Old Infant.

BACKGROUND Black hairy tongue is a self-limiting, usually asymptomatic, benign lesion that most often affects men and people aged over 30-40 years. The lesion is extremely rare among newborns and infants. Lingua villosa nigra is characterized by the presence of elongated filiform papillae of the dorsum of the tongue, which gives a hairy appearance. The overgrown papillae can accumulate fungi, bacteria, pigments originating from food, or any other debris that can contribute to the discoloration of the tongue. The prognosis for black hairy tongue is positive. Gentle tongue brushing or scraping as well as the elimination of predisposing factors usually leads to cessation of the lesion. CASE REPORT A generally healthy, exclusively breastfed 3-month-old female baby was admitted to the Oral Pathology Department of Wrocław Medical University due to a persistent tongue lesion. Intraorally, dark, blackish, elongated tongue papillae were observed. Three weeks earlier, the baby's pediatrician had diagnosed thrush and prescribed systemic antifungal treatment with Nystatinum, without prior mycological examination. The lesion did not resolve and the girl was referred to the Department of Oral Pathology. A meticulous medical and dietary interview revealed that since the 28th day of life the baby had been supplemented with vitamin C. This, together with an intraoral examination, led to the diagnosis of black hairy tongue. The lesion disappeared partially after 4 weeks of tongue brushing. CONCLUSIONS To prevent infants from undergoing persistent and unnecessary treatment (topical or systemic drugs) or additional diagnostic procedures, such as biopsy, it is essential to be familiar with the characteristics of lingua villosa nigra as well as its origin and management. The consideration of this condition is invaluable for babies' health and safety.