What Causes Intense Itching Around The Anus?

I have intense itching on and around my anus for atleast 4 months now and it's persistant, i may get rid of it for a day or two, then it's back and the wrinkles around my anus are inflammed/puffed out. It occurs any time of day and night and in short bursts of intense itching almost like a pinch, i looked it up before and have tried many different things like. . . Pin worm med, Jock Itch med and even a yeast infection medication. Nothing is working! Please Help!!

I'm 25 yr old male, smoker, no drugs, alcohol about twice a month