hello,Since you havent said about other symptoms I think your daughter is having prickly heat rash. Heat rash develop in hot or humid conditions where sweat glands produce excess sweat. sweat glands produce elevated redcolor papular rash with white heads. They are itchy. As you ave desribed they develop on heat or sun exposed areas. upper trunk , face, legs and thighs. You dont have to do anything for the rash it would go away on their own. Bathe daily. be under a fan or A/c matchine when there is excess sweat, keep the rash dry. Dont use oily creams when excess heat is present. It would aggravate the rash. You can use calamine lotion or hydrocortizone cream when the rash is very itchy. hope this helps. thank you