Yes, like Rebekah, my Ni allergy results in swelling and BRIGHT red flushing at the contact site, and
by far, earrings are the worst culprit, though necklaces, rivets or buttons on clothing, etc. can also do it now, and I cannot wear even so-called "stainless" or 10kt or 14kt gold... and even 18kt has begun bothering me in the past five years or so.
I can't wear my wedding rings for more than a few hours.
A nickel allergy is something that most frequently: a) appears at the site of longest/most continuous exposure, which for women is most often pierced earlobes, b) worsens slowly with time.
I first noticed problems with earrings when I was in high school, ~3 decades ago. At that point, I could not wear most costume
earrings, but higher quality sterling was fine for a few years. Then I was able to get away with coating sterling with nail polish for a couple of years, then not. By the time I graduated from college, I was beginning to have trouble with 10kt in earrings, though I could still wear it in necklaces, rings, and bracelets all day without any trouble at all. This was about the time that I was developing a latex allergy.
During graduate school, I wore so little jewelry that I didn't notice any appreciable worsening of the problem. It was when I was in a professional position afterwards and wearing earrings daily that it got worse-- in a hurry, particularly after pregnancies. I can only wear my 18kt earrings for a few minutes now, and I know which pairs are more Ni-contaminated than others. I also have "Ni-free" earrings...
that my body says aren't. This is, though, a different mechanism than an IgE-mediated allergy. I'm apparently one of the lucky people to have both types of responses. Most people tend to one profile or the other... which means that MOST people with severe IgE-mediated allergies won't ever struggle with this kind of contact sensitivity. (Just the lucky ones like Rebekah and I, apparently.) Good to know that anaphylaxis is a ticket out of
something, though, isn't it?
But also-- during times of very high pollen, I will hive at ANY place where clothing or anything else is held tightly against my skin for an extended period of time: bras, waistbands, sock cuffs, bra, etc. THAT is run amok dermatographism, which I have anyway-- I just naturally have a histamine response in the skin that is completely haywire. You can literally write on my skin with a toothpick or dull pencil and watch it hive up. Most of the time (low pollen, relatively empty 'allergy cup') I don't have problems with 'normal' stuff like clothing.