Vulvar fissures often occur in the bottom part of the vaginal opening or, sometimes, at the top. It's the recurrent splitting tearing of your vulvar skin or lining. It's a condition that occurs when you're suffering from vulvar skin conditions that cause scarring and inflammation, like vulvar lichen sclerosus, thinning of vulvar skin, or poorly healed perineal tear from childbirth or overactive pelvic floor muscle dysfunction.