Hairy leukoplakia is a white patch on the side of the tongue with a corrugated or hairy appearance. It is caused by Epstein-Barr virus (EBV) and occurs usually in persons who are immunocompromised , especially those with human immunodeficiency virus infection/ acquired immunodeficiency syndrome (HIV/AIDS). This white lesion cannot be scraped off. The lesion itself is benign and does not require any treatment, although its appearance may have diagnostic and prognostic implications for the underlying condition.
Leukoplakia is a condition in which thick, white or grayish patches form usually inside your mouth. Smoking is the most common cause. But other irritants can cause this condition as well.