We used Daktozin when Charlie had nappy thrush, and when he gets a little bit of redness we just use zinc to form a barrier. Otherwise we don't use anything (he gets a bit of eczema so I don't want to expose him to any unecessary chemicals. We don't use wipes unless we're out - I just cut up some cheap brand Chux wipes (they don't have any chemicals on them) and keep a clean bowl of water handy to wipe when I'm changing him. These wipes can be washed too - it saves me a fortune!

Hope it clears up - have you been to the doctor? It might be something that needs a prescription.