itching

So I had sex a couple days ago, and about a day or two after I started to itch down there. I didn't know whether it was just irritation from the sex or what but it's still here. I showered and put anti itch cortisone cream on it, and it feels better temporarily when I apply it. But after a while it wears off and starts to itch again. What should I do? Idk what the problem.