There are many causes of sudden vulvar itching, such as inflammation of the vulva and vaginal inflammation, and irritation of the vulva when discharge increases may cause vulvar itching. In addition, if there are parasites at the pubic hair, such as pubic lice, they may also cause sudden vulvar itching. Itching of the vulva is more pronounced in the presence of leukoplakia, and is worse at night. Itching is also particularly noticeable if there is mycosis fungoides. If you are allergic to a certain kind of sanitary napkin or wear chemical fiber underwear, an allergy to a certain kind of underwear may also cause vulvar itching. So you must treat the symptoms according to the cause. You can wash your vulva with cleanser, apply hydrocortisone ointment, and take anti-allergy medication such as restorative medicine if necessary. If the symptoms do not improve in 3-5 days of treatment, or if the symptoms are getting worse, you must go to the hospital in time and be treated under the guidance of a doctor.