Smeghead, don’t put the book away just yet. You mentioned Type I hypersensitivity. What are the other kinds of hypersensitivity? I assume Types II, III, etc. are greater in degree. What stage can it be called an allergy? In other words, when is a reaction merely due to hypersensitivity or due to an allergy?
Rudy Mancke has said that people are sensitive to poison ivy, not allergic. (Not all people, but many.) Yet some people get some pretty serious hives due to the oils in the poison ivy plant.
Atreyu, like you my mother developed an allergy to shrimp after she reached adulthood. She never has been allergic to anything else, and is otherwise extremely healthy, so it’s not necessarily likely that you would have any other food allergies.
I’m not allergic to any foods, though I have plenty of problems with hay fever and skin allergies, but my son is allergic to bay leaf and scallops, which he was certainly not exposed to in infancy.
Which things we develop allergies to seems pretty random to me.
Smeghead: “gastrointestical tract” made me laugh!
But on a serious note, are other allergies, such as to pollen or mold, related to food allergy, or does it work differently (a type II or III hypersensitivity)?
OK, book’s back out.
All allergies are type I reactions. Other types are other diseases.
Type II reactions involve antibodies destroying normal cells. The most common example is with blood transfusions when you get the wrong blood type. Your antibodies (IgG, in this case) react with and destroy the foreign cells. This is also what happens between a mother and fetus with incompatible Rh types.
Type III reactions are interesting. They’re caused by circulating immune complexes, which can be thought of as wandering balls of antibodies and antigen stuck together. This is kind of a jump-start to the immune system in the area, causing inflammation, itching, etc, etc. Insect bites are this type of reaction.
Type IV reactions are referred to as “delayed-type hypersensitivity”. This is what happens with poison oak and the like. The major difference is that it’s a type of T cell that’s activated, rather than B cells. It takes 24-48 hours to activate these cells, thus the “delayed” description.
“Gastrointestical tract”?! Sheesh. :rolleyes:
Here’s a useful site with additional information:
Our little boy has is very allergic to milk and our pediatrician gave us an Rx for an epinephrine injector that we basically keep around wherever the little guy is.
As I understand it, if he had an anaphalactic (sp?) reaction and his throat started swelling closed, this shot could stop/reverse it enough for us to get him to the ER. I’ve heard lots of people with severe peanut allergies carry the EpiPens because trace amounts of peanuts can get into everything it seems.
One of the major theories concerning allergy in general (and its notably increase, particularly in more recently developed countries) is the “hygiene hypothesis,” which posits that allergy is the product of an immune system with too much time on its hands. Current thinking seems to be that certain gut infections help the developing immune system “prime” itself to better identify which invaders are benign and which are dangerous.
Another theory - possibly interrelated in practice - is that parents unwittingly sensitize their children to certain foods by introducing them too early into the kids’ diets. One article I found mentioned that rice allergies are increasingly seen in Japan, although in this country rice is considered hypoallergenic. When I taught English in public schools in Japan, several teachers commented to me on how much allergy had increased among the younger generation - which makes sense considering that the country didn’t fully attain first-world development status until the 1960s. Similarly, allergy has increased markedly in the former East Germany and in Estonia, both of which have undergone dramatic leaps in standard of living.
At least in concept, the two theories dovetail quite nicely - and I may be a pretty decent example. My mom, a full-time homemaker, kept a typically tidy, middle-cass home. I was discovered to have pretty serious environmental allergies almost the instant I came home from the hospital - I reacted badly to the stack of plush toys waiting for me. Mom took one snapshot of me with the toys so she could send thank-you notes, and then loaded up the car to give them all to Goodwill.
Mom also didn’t lactate (I’d be curious to see if allergies are more common among formula-fed babies like me), and my parents quickly learned that I was allergic to cow’s milk. Fortunately, the local mall had a health-food store that carried goat’s milk, which was no problem. By the time I started solid food, they treated me as if I were allergic to everything - for the better part of two years I had a diet of about seven things.
My only remaining allergy is to potatoes. Although mighty inconvenient, it doesn’t quite provoke anaphlaxis (I get a kind of proto-anaphlaxis that I can nip in the bud pretty quickly) so I can go to restaurants without too much worry. What’s incredibly frustrating - and I can hear that frustration in some of the posts here - is to have your reaction minimized. “Oh, you can just take the potatoes out!” Uh, no, I can’t - whatever chemical it is that provokes the reaction leaches into the rest of the food. “How could you be having asthma? The potatoes are in the other room!” Well, did you just see the steam billowing out of the kitchen when the potatoes were drained? I just breathed that. (On the psychosomatic front: frying potatoes smell plenty nasty to me, but I don’t get asthma; I’m guessing the quick cooking seals the surface and prevents enough steam from escaping. Boiling potatoes are the worst, with baking coming second.)
That was the right link for East Germany and the wrong link for Estonia. My bad. Can’t find the Estonia link now.