Estrogen deficient vulvovaginitis is characterized by an inflammation of the vagina and vulva caused by a lack of estrogen hormones. The vulva can be defined as the external portions of the vagina, including the inner and outer lips (labia majora and labia minora), the vaginal opening and the area surrounding it (vestibule), the urinary opening, and the skin between the vagina and the anus (perineum). Because estrogen deficient vulvovaginitis is due to the thinning (atrophy) of the vaginal walls resulting from a lack of estrogen, it is also known as atrophic vulvovaginitis. Estrogen deficient vulvovaginitis is most common in postmenopausal women. Although atrophic vulvovaginitis can cause irritation, itching, and a slight vaginal discharge, it can be treated with estrogen medication or lubricants.