Red nodules on the vulva are commonly seen as follows: 1. The most common is folliculitis of the vulva, or boils caused by folliculitis. It is also important to look for skin allergies, such as allergies to soap, vulvar lotions, and to see if you have recently changed to a new brand of underpants or sanitary napkins and are allergic to them. 2. Skin diseases can also cause vulvar nodules, and in gynecology, the most common cause is inflammation, such as vulvovaginitis, vaginitis, vaginitis has Mycosis fungoides, trichomonas vaginitis, bacterial vaginitis, all of these can cause an increase in leukorrhea, which can stimulate the vulva to have red nodules. So when there are red nodules on the vulva it is still important to go to the hospital and get checked to find the cause.