I had this a while back and it went away, so when it came back I thought it would again.
It's just like a dry white are around the clitoris, it seems worse when I am on my period, but this could be a co incidence.
I have changed to cotton knickers and even used a fanjo wash incase it was my soap.
I have never had a particular washing powder or liquid so don't know if I have had a reaction to it.
It kind of feels like it's been rubbing, I am irrationally worried it might actually rub away. 
it's a bit itchy but not sore.
I know I should just go to the GP, but I really don't want to. I know how silly that is.
Any advice ?
Tia.