Probably this;
http://en.wikipedia.org/wiki/Tinea_cruris
Go to the f*cking doctor anyway you big girls blouse, do you think thats the ugliest thing they'll have seen this week? He might have a laugh afterwards, thats the worst that could happen. ffs, if I managed to cope with a middle-aged lady doctor checking me out for chalfonts I'm sure you could survive the utter humiliation of telling your quack that your rings itching.