Itching outside the vagina may be caused by allergy, physical or chemical factor irritation, infection and other factors, which need general treatment or medication. 1. Physical or chemical stimulation: such as the vagina and its neighboring urethra, anal discharge of menstrual blood, vaginal secretions and other stimuli. In this case, you should keep the vulva and vagina locally clean, and stop using drugs that cause irritation to the vulvar skin, and change breathable and clean underwear regularly. 2. Infection: such as staphylococcus, Escherichia coli and other bacteria, Pseudomonas and other fungi and other pathogens. Need to keep the vulva and vagina clean, according to the pathogen selection of sensitive antibiotics, such as clotrimazole, miconazole, metronidazole, tinidazole and other preparations. 3. Allergy: localized redness, swelling and itching after contact with sensitizing substances in the vulva. It is necessary to identify the allergen and remove it in time, and keep the vulva dry and hygienic. It is recommended to consult a doctor in time to receive standardized diagnosis and treatment.