Is This Considered An Allergy?

[ptkds]

I most likely have DH. I go the the derm next month, and hopefully they will do a biopsy at that time since it takes 3 months to get in there! But after reading another post on here, I put some iodine on a bandaid and put it on my arm. It was itchy almost immediatly, but I left it on for almost 24 hrs. I took it off 2 days ago, and I can still see exactly where the iodine was. It is all red and bumpy, and the rash is shaped like a perfect rectangle from the pad on the bandaid! It has gotten worse since I took it off. So, my question is, should I consider this a true allergy to iodine? I don't know if I should worry about it enough to let medical workers know so they don't do procedures that involve iodine. I don't have a bad anaphalactic reaction, so I don't know if it is that serious. What do you guys think??