I got allergy skin testing again a couple days ago, and my allergy tests have become positive again!
Up until about 2008 I had positive reactions to most of the allergens in skin testing. Then over years, my skin tests gradually went negative – as I was getting sicker with allergies!
I've been sick for about the last 6 years from allergies. At first I was OK in the fall, then I was sick all the time. For a long time I didn't know what it was, because I don't often have the obvious allergy symptoms like watery eyes, sneezing etc.. Mostly my allergies make me feel fuzzy-headed. It's a feeling in my head that makes it difficult to think, and physically I don't have much energy either.
A paper I read suggests that IgE produced in the nose might not go into systemic circulation if there are increased numbers of mast cells – so that skin and blood allergy tests would be negative. Chronic exposure to allergens tends to result in more mast cells in the nose – so this might explain why my skin and blood testing for allergens became negative, even as I got sicker from allergies. I have been trying very hard to reduce my allergen exposure, and now my allergic reactions don't seem to last as long and they aren't as severe as they were – although I'm still just as sensitive. I used to get sick for 5 days from an allergen exposure, but now I seem to feel better after more like 3-4 days. So some of the changes that happened from chronic exposure have gone away somewhat.
All of my positive skin test reactions were to molds though, and uncommon molds. I had positive reactions to the common mold allergens, such as Aspergillus, before my chronic allergic sickness started. It suggests that I still have those mold allergies, but they have “gone local” and still don't show up on skin tests. I have allergic reactions to many molds, so bad that I usually wear a mask while shopping for produce, since I've gotten sick for days because of mold on it.
My allergy skin testing becoming positive again, suggests that chronic exposure to allergens did cause my allergy tests to become negative.
It's nice to have some outside validation for my allergies, it's no fun when other people think I might be making it up. I would have a very hard time believing I didn't actually have allergic reactions, because it would mean I was somehow psyching myself into being fuzzy-headed for days on end. I know I can psych myself into feeling kind of hazy for a short time – when I'm paying attention to it, but the fuzzy heavy-headed feeling is more concrete than that, and quite unpleasant. Also, I often feel like I'm having an allergic reaction, then later I discover some mold causing it.
Probably even when people do have allergies, part of their allergic reaction is learned by their brain. I read that with “multiple chemical sensitivity” reactions, which do seem to be something that people psych themselves into, it's a matter of the brain learning to have a certain perception over time (thus it is contagious and you can get MCS from a MCS support group). Probably with allergies a similar thing happens so that one “learns” the reaction somewhat, over time.
Also with positive allergy tests it's more likely that when Obamacare pushes me into getting insurance, the insurance co. will pay for Xolair - a very expensive allergy medication I'm getting. I'm cynical about Obamacare because I know too well how easily one's real needs can fall through the cracks.