My first allergic reaction

Monday night, I injected Humira like I have every 10 days for the last two years. Tuesday morning, I took my regular dose of Methimazole (I now also have Graves disease, an auto-immune disorder of the thyroid).
I noticed I was itching a bit Tuesday morning but I didn't think much--ragweed season AND our neighbors mowed. Got a little worse through the day; at 8 p.m., I was digging at my arms, hands, chest, wherever.
At 9:00, I took a 25 mg Benadryl; at 10, I took another. Normally, that stuff stops the itch and puts me out. Not this time. Paul slathered me with hydrocortisone cream and then with Benadryl cream. I reapplied in the wee hours Wednesday morning. At 3, I was taking a lukewarm shower.
At 8 Thursday morning Paul and I were at the Little Clinic. She didn't know what the heck was going on but recommended I call my rheumatologist and endocrinologist. At 11:00, we were in the rheumy's office.
When he walked in, he started to say something and then noticed my left foot with the redness from where I had scratched so much, I left raw spots and knelt down, looked at both arms (with blood spots), etc. etc. He's about 90% sure it's not Humira, but the test for that is to inject my regular dose and we'll know.
The endo said something similar: lay off Methimazole and then try again. If it's Methimazole, I have no idea what we're going to do because if you itch on it, you tend to itch on the other drug. The more I've read, the more I believe it's Methimazole--if you're going to react, you do so at about four weeks, when levels build up in your body; Tuesday began my fourth week. Got a big shot of DepoMedrol and a prescription for Doxepin to go along with Vistaril.
Should be the end, right? Nope.

Evidently I woke Paul up in the shower at 6:30 yesterday morning. When I pulled the shower curtain back, he took one look at my tear stained face and said you’ve been scratching all night. I showed him the raw spots on my neck, chest, shoulders and arms. He said we’re headed to the Emergency Room. You can’t do this anymore and you certainly can’t keep scratching more raw spots all over yourself.

So now I'm on 60 mg of Prednisone for the next five days. I'm feeling better this morning than at any time since Tuesday. But sheesh, I really don't want to take even the 5 mg of Methimazole I plan on taking on Wednesday (because that's the only way we're going to know). One benefit--I can't inject Humira on Thursday night so the Pred will get me through until I can a week from tomorrow.
One funny out of this whole miserable week--While he's getting everything ready, my rheumy looks over at Paul and says she throws me a curve ball every now and again (I've been his patient for a good while--he knows me entirely too well), but it's good that she recovers well. Then he laughed and Paul smirked while I sat, scratching.
Just call me curve ball.....