Hives in Remission, but Why?

Since Monday of this past week, I have been completely hive free. I wonder if it could be any of the following three things, which all happened around the same time:

• Steady dosage of antihistamine -- I've been doing one allegra each morning for 1.5 weeks. Did it just take time for that to 'build up' in my system in order to be more preventive?
• Stopped using fabric softener -- Boy will I feel like an idiot if this turns out to be the culprit. But at the advice of a family member, I stopped using a liquid fabric softener that I purchased several months ago. I hadn't been using it on all of our laundry, only on towels and our sheets/bedding. I don't think this is the cause though, because it doesn't explain the "massive outbreak" days that I have had when the hives go gang-busters when I have worked up a sweat.
• Gluten-Free diet -- After poking around online, a number of people have asserted that going gluten-free has helped dramatically with chronic hives. Gluten free isn't as hard as most people think; I have found breakfast and going out to eat to be the most challenging. I did buy a few boxes of gluten-free breakfast bars, and when dining out, I know what to specifically ask about to make sure it is gluten free (common 'gotchas' are soy sauce and soy products, as well as salad dressings and other sauces where wheat flour is used as a thickening agent). I find that most wait staff are totally ignorant of what gluten-free means. I think being GF is probably a good idea for me in general, so this may be something I just decide to make a commitment to doing.

So now, the challenge is because all those things coincided around the same time frame, it is now difficult for me to know which one has been the reason for no hives in five days. Not that five days is a long stretch, but it's the longest stretch I have had since my last "remission" over a month ago.

Last week, my PCP recommended that I speak to a Rheumatologist to get the auto-immune perspective. I had an appointment on Friday afternoon, and he suggested that I continue to stay gluten-free for next two months, and see him again and we'll go from there. He also wants to re-check my Thyroid Antibody levels and Thyroid Function (TSH, free T3, free T4), so I need to get those done next week. He said that Thyroid Antibody levels fluctuate, and if they are higher now, that would be something they want to identify. (I last had them checked in December.) He does have a medication that he said we could try, if the hives continue to come and go, but I can't remember the name of it; they use it on people with autoimmune issues who get hives.

I keep scanning my hands, arms, neck, waistline, etc. a few times a day wondering when the hives will make their appearance again. Here's hoping they don't...

If I continue to be hives free after two weeks, I am going to first try the fabric softener on my laundry again, and I'll do that on a day where I will skip the Allegra. I figure, that is the easiest one to test.