I know the feeling!!! I can't go near anything but Tylenol.
I was breaking out in hives for weeks before I realized that it was the Motrin I was taking. I woke up at 2am one night because I couldn't breath. DH turned on the light, looked over at me and screamed. My face was unrecognizable.
I thought I was going to have to use the epi pen right there... but the benadryl kicked in and I went to the hospital.
I don't know what brought it on. I have never had a problem with over the counter meds until I turned 25!