what causes this,and name
Is yeast infection, (fungal infection) can not be treated with anti-biotic tablets, because they kill the bacteria that help in treating the infection. Use Ketoconozole tablets and Cream.
This may be vulvar ulcer, lichen sclerosis, human papillovirus (HPV), syphilis, genital herpes (HSV-2), molluscum contagiosum, psoriasis or vulvovaginitis but proper medical diagnosis (test) can tell what kind of infection is that in conjunction with the signs and symptoms such person always experience.
This is my little suggestion