What Causes Itchiness In Anus With Bumps?

a few days ago my anus started to itch. The next day my buttocks crack was a little red and it had a few little bumps at the top of my buttocks crack and there is a few at the bottom of my buttocks crack. I been keeping it dry and putting basitracin on it. the bumps got smaller but still are tender and its not as red down there. I work out 3 to 5 times a day and sometimes sweat gets in my crack and at night i am always sweaty. i dont think its an std b/c me and my husband are faithful to eachother! help me pls!