1, do not pay attention to the cleanliness of the external cause, menstrual blood or vulvar secretions, urine and stool and other pollution accumulation and cause itching. 2, vulva or cervical inflammation leads to increased leucorrhoea stimulating vulva causing itching. 3, vulvar skin suffering from eczema, allergy, inflammation, pubic lice or neurodermatitis. 4.Diabetes mellitus can stimulate vulva due to more urine or with Candida infection vaginitis. 5, premature ovarian failure, the body estrogen levels decline vulva too dry secretions reduced. 6. Wearing tight underwear, chemical fiber products, alkaline soap or overheated water to wash vulva, excessive hygiene to destroy the self-cleaning effect of vagina.