Monday was finally the day of the dermatology appointment that took a couple of months of waiting. As expected, the dermatologist wished me luck, said I could try an allergist but it probably wasn't an allegy, and wrote me a prescription for antihistamines. This is not really a bad result, it's just another chronic condition that won't kill me, and which I had all along anyway (except it had never flared up nearly that badly). I'm to continue with the three Claritin a day diet, plus now I have hydroxyzine I can use as needed. The condition has improved a lot, so maybe I'll be able to go off the Claritin (actually 'Wal-itin' from Walgreens).
I haven't been exercising except a few tries, since the flare-up, because exercise makes the hives worse. The dermatologist thought of this himself, without my raising the issue, and suggested taking a hydroxyzine prophylactically before the exercise. Maybe to avoid using up the hydroxyzine I could use non-prescription diphenhydramine much of the time.
The doctor examined the skin on my back and saw no signs of sun damage, stating that the few blemishes were probably inherited and/or stuff like that. It certainly isn't thanks to lack of sun or diligent use of sunblock when I was a kid, so it must be the goodness of my skin. It doesn't wrinkle much, either, so it's a good skin, except it's also a bad skin because of those other things.
I told the dermatologist I had a cold and I sure sounded like it, but it got better almost immediately and more fully than a cold would seem to do, so I think it may have just been a temporary manifestation of fibromyalgia. I get that a lot, and don't know what else to blame. I think it may have been triggered by this TMJ pain I've been having lately, which gives me a sore throat.