Oral mucosal hairy leukoplakia is one of the signs of severe systemic immune suppression, and its occurrence is related to Epstein-Barr virus (EBV) infection, which can be seen in HIV-infected patients, bone marrow or organ transplantation patients. 1. HIV-infected patients: HIV infection can cause progressive immunodeficiency, secondary to various opportunistic infections, in which Epstein-Barr virus infection will appear as hairy white spots on the oral mucosa. 2. Patients after bone marrow or organ transplantation: after transplantation surgery, immunosuppressants are usually needed to reduce the rejection reaction, and opportunistic infections are easy to occur, and infection with EBV can lead to oral mucous hairy white spots. There may be other causes of oral mucous membrane hairy white spots, it is recommended to go to the hospital in time to receive targeted treatment as soon as possible.