My daughter is 9mths old and her rash started at 4mths and it was regular. Our pediatrician gave us the zinc oxide, and then Nyastin. Month after month, the rash is still there and we've tried desitin regular and max, butt paste, and as of now lansinoh diaper cream and vaseline. The rash now looks like she burnt her skin, gets blisters on and off that are not pus filled. They get bigger and then turn red adding on to the chaffed looking area and covering the whole upper half of her vagina. it's itchy, and seems very irritated since she tries to claw through her diaper to get to scratch it, and cries at diaper changes. What is this rash and how can i get rid of it once and for all!?