Itchy rash on 8 year old

[mzdemeanour]

My 8-year-old DD has got a rash on the inside of her upper thighs. There are tiny hard raised spots which itch a lot. Anyone got any ideas what it might be? Do I need to take her to the GP? Wouldn't normally worry too much but we are going away on Sunday and am worried in case it is something that might be infectious/need treatment.

TIA for any help.

Forgot to say, she is okay otherwise - no temperature or complaints of feeling unwell and she has had chicken pox and has had MMR jabs.