I went to er for an infection in my left arm. The doc cut me, drained the infection, gave me 2 different antibiotics and sent me home. With a prescriotion for cephalexin 500 mg, and sulfamethoxazole tmp ds tablits. 3 or 4 hours later my penis started to itch, as time went on it got worse. I woke up the next day with a crazy itch, but now it was also red at tip, swollen below the head, and had a few tiny blisters on it. Can this be a reation to the meds?