How to deal with a major skin irritation?

About a month and a half ago I sprained my ankle quite badly. Being a figure skater, its rather difficult to try and stay off the ice, and I have skated on a sprained ankle several times before so my physiotherapist taped my ankle for me before I went to practise,which is great for support and has usually given me no problems. A few years ago I had my ankle taped with a latex-type tape though and I had a major allergic reaction to it causing it to be red and bumpy for a few weeks, however this went away. I told the therapist this and she avoided that tape, but after the third taping I took the tape off and had a reaction to what seemed to be the styrofoam patches she put on the top of my ankle and at the back of my Achilles tendon. This reaction was terrible. It was so uncomfortable for weeks, at first I used an over the counter hydryocortisone cream, but that didn't work so I had to go to a medical doctor to get a rx for betamethasone valerate cream and a super strong type reactin medicine. Eventually a few weeks later this went away. Now last week I tried getting my ankle taped again with just pro-wrap tape and the white sports tape over top and my skin was fine. BUT, 2 days after taking the tape off my skin has reacted AGAIN! This time its back in full force. It is so itchy its almost painful and it seems like the cream is giving no relief. I am taking Benadryl, but that seems to be doing nothing either. Why does this keep happening?!?! It seems bizarre that the irritation would occur 2 days after taking off a tape that I know gives me no trouble. Any advice?? Im desperate