The causes of vulvar enlargement are: 1. vulvovaginitis, inflammation of the mucous membrane of the local skin of the vulva causing vulvar redness and swelling, accompanied by itching and vulvar erosion. 2. vulvar enlargement caused by vaginal inflammation. When mycosis vaginalis, trichomoniasis or bacterial vaginitis occurs in the vagina, a large amount of leucorrhea containing pathogenic bacteria is stimulated by the vagina, resulting in vulvar skin infection and local swelling of the vulva, accompanied by a burning sensation. 3, vulvar leukoplakia, resulting in local skin mucosa hyperplasia, itching and erosion of the vulva, resulting in vulvar edema. 4, physical stimulation of the vulva, trauma or contact allergic reaction can also cause vulvar redness and swelling. Allergic reactions can also cause sudden edema in the vulva. 5. Eczema of the vulva or herpes zoster of the vulva can cause severe itching and pain in the vulva, and long-term stimulation can cause local edema and hyperplasia.