What should I do if I am allergic to my ear care antiseptic?

Stop using it! Wash with nothing but plain water and mild, unscented soap until fully healed. If you have a rash or bad itching on the outside part of your ear, you may want to use some over-the-counter cortisone cream for relief, but never put cortisone or other over-the-counter meds into your ear canal. Probably not necessary to use an antiseptic in your ear unless instructed by your dr for a specific problem.