And the tests sometimes yield false positives or negatives. My allergist told me that food allergy tests in particular are of limited use because of the processing they have to do to create the serum used for the test.

I've been noticing some strange patterns with the chronic hives that I get. (The doctor thinks they are autoimmune though he did not order testing to confirm that, and I'm okay with that since the treatment is the same either way.) In the past I've had several big flare ups right before getting my period. Last winter they kicked up during a perimenopausal hormone swing from several months of hot flashes to several months of periods. At the same time I started having joint pain in several fingers on my left hand. The hives calmed down and the joint pain went away, but now they're both back again this week. I did a bike ride in very hot weather on Saturday -- the first time out in the heat this year, and it hit me hard because I'm completely unacclimated -- and I think that caused this most recent flare, as I've gotten heat rash and hives in the past after long bike rides on very hot days.

I've never noticed any relationship between my asthma symptoms and flare ups of hives or hormone swings, but I wouldn't be surprised if things like hormones or stress (whether its from being out in the heat or moving or starting a new job) can combine with environmental factors to make asthma worse.