Cat has pimply red, sore-looking rash under one front leg

[rabianne]

I am wondering if there is any topical cream I can buy at the pet store to treat this rash. She seems to be in no pain and unaffected when I touch it, but it looks like it should be sore. She is in great health and this is the only area on her body where I see the rash. She's never had a problem before like this.