The causes of vulvar itching are very many, and not all cases are suitable for the use of erythromycin ointment for external application. Therefore, when the patient appears vulvar itching, must find the cause before symptomatic treatment, can not indiscriminate use of drugs. Clinically, vulvar itching is most common in inflammatory diseases and allergic diseases. Inflammatory diseases can be divided into bacterial inflammation, trichomoniasis, mycobacterial inflammation and so on. If it is mycobacterial inflammation, you need to choose clotrimazole, dakinin ointment external coating. If it is bacterial inflammation or trichomonas inflammation, you can use erythromycin ointment for topical application to reduce the symptoms, but ultimately, you have to choose to use metronidazole or tinidazole for treatment. If the vulvar itching is caused by allergic diseases, you need to remove the allergens, and if the itching symptoms are more serious, you can use dermatophyte for topical application.