Itching before menstruation is often related to vulvovaginal inflammation, and in some patients it is related to allergy or vulvar whiteness changes, and in a few cases it is related to various other physical and chemical stimuli. 1. Vulvovaginal inflammation: most women itch because of vulvovaginal inflammation, bacterial vulvovaginitis, mycosis fungoides, trichomoniasis, senile vaginitis and so on, which may lead to vulvar itching before menstruation. 2. Vulvar allergy: including condom allergy, allergy to new underwear or pads, and even semen allergy in a few people can also lead to premenstrual vulvar itching. 3. Vulvar white changes: women with vulvar leukoplakia or tinea versicolor may also experience vulvar itching. 4. Physical and chemical irritation: Some women may experience itching due to vulvar exposure to various irritants, such as vulvar lotions. Itching before menstruation may also be caused by other reasons, it is recommended to consult the obstetrics and gynecology department in time for examination.