One day Anni was twirling and singing one of her original compositions.
"It's my gift!" she declared.
Dizzy, she fell with spectacular gracelessness.
Laying on her back on the tile floor she began flapping her arms and legs
as if she were making a snow angel.
"Falling down is also a gift!" says she.

Monday, August 15, 2005

the hygiene theory

An update on Annika is coming, but meanwhile I have gotten caught up with some wonderfully provocative comments made on my seemingly innocuous (and badly titled) about rings and things post below. First, Andrea noted, "But--aren't those little antibacterial thingies supposed to be the tools of the devil or something?" That's exactly why I read her every, single day: she is absolutely unhesitatingly putting herself out there, and pulling no punches. I posted a longish reply to her comment, basically saying I had heard no such talk of satanic activity swirling around the Purell business, but that I would be sure to check the bottle for any sign of a moon and stars. I did mention a study, though, and didn't give a link. So here's a report on the study showing hand sanitizer decreases incidence of tummy bugs. Then Mike, an old college buddy and also an extremely smart and kind guy, questioned my unbridled enthusiasm at the proliferation of hand sanitizer in our world by bringing up the hygiene theory of allergies and asthma. Basically, this theory supposes that the noted increase in allergies and asthma in developing countries is due to our increased concern with hygiene and more frequent use of antibiotics to treat bacterial infections. Thus, the immune system is left with nothing to do and goes a little stir-crazy, eventually beginning to attack our own cells rather than those of harmful foreign intruders, leading to allergies and asthma. I posted a reply to his comment right away, but then couldn't stop thinking about what he had said. So I began to write another follow-up comment, which eventually became long enough that I decided to make it its own post instead. The first thing that I neglected to say to Mike in my quick response was that I was sorry to hear about his as-yet unidentified allergy. Allergies are not to be trifled with, and I hope he is now armed with an epi-pen. Let me also say up front that I do believe that messing about with the immune system is likely to lead to allergies. There is new work being done in the transplant community showing that kids on immuno-suppressive drugs tend to be much more prone to developing violent, life-threatening allergies. I know of one little boy in particular who seems to be allergic to damn near everything, and I do mean everything. It's a nightmare. So I don't want to pooh-pooh the role of allergies in people's lives. And it seems reasonable that cutting down on the immune system's work, either artificially by drugs or by simply living in a cleaner environment and giving antibiotics to treat bacterial infections, seems a good theory to account for higher rates of allergies. But here's the thing: Some of the countries with the lowest incidence of allergies/asthma are in the developing world, where infections and parasites during childhood are rampant. Now, I have no doubt that children who contract these parasites/infections and fight them off on their own come through with stronger immune systems and smarter immune systems (i.e. immune systems that know better than to attack themselves, as is the case with allergies). But, geez louise! The rate of childhood mortality in those countries? Pretty high. It seems likely that if our children are exposed to many of these infections that we now shelter them from, that there will be quite a few children coming through with stronger, smarter immune systems. And there will also be a sizeable group who dies, either from a weaker immune system than the survivors or from the bad luck of being exposed to a more virulent strain. I guess my view is biased because I am the mother of one of the acknowledged "weak ones." But I'm just not sure that this approach is one that we would want to take as a society ("let 'em get sick and the strong and lucky ones will survive and be stronger for it..."). Maybe I'm straw-manning the opposition here. I don't mean to. Feel free to make a compelling argument the other way. I'm truly interested in thinking about this a bit more. Here are some other caveats to the hygiene theory that I came across in my quick reading: 1) The correlation between more infections and lower rates of allergies/asthma only holds for the first 6 months of life 2) The hygiene theory does not explain why there has been a rise in allergies/asthma in poor, inner-city environments, where the hygiene theory predicts there should be lower rates 3) a new study suggests that the observation that children born as second/third/later siblings show lower rates of allergies/asthma may be due to the mother's changing immune system with each successive pregnancy, rather than the supposition that later children are exposed to more bugs thus making them less likely to develop allergies (the hygiene theory) 4) Some of the earlier studies on the hygiene theory have been criticized as flawed as they often rely on self-reporting questionnaires and may suffer from faulty set-up. Here's one such report of a study, along with the noted criticisms. Also here is a general overview of allergies, the hygiene theory, and alternative hypotheses I suppose that, as a parent of a post-transplant child, I am too used to looking at life as a series of gambles and trade-offs. So when I hear that washing hands frequently, which is certainly and demonstrably beneficial to one's health, may also lead to later allergies and asthma, I tend to fall on the side of choosing to take that risk in order to avoid what I see as the greater risk to my child's health (including Frankie, not just Annika). I had heard of the hygiene theory before Mike mentioned it, but it's worth noting that I always read it in the context of "working moms shouldn't feel guilty for sending their children off to daycare, where they will be exposed to more germs than the infant of a stay-at-home mom." This, I think, is really the most useful approach to take on the hygiene theory. Decreased hand washing would be the wrong action to take in response to this theory.

12 Comments:

Blogger liz said...

I think it's far more likely that increased pollutants are responsible for the increase of asthma and allergies than increased hygiene.

We're breathing in toxic chemicals every day (carpets, paint fumes, pressure treated lumber (hello, arsenic?) - not to mention car exhaust, factories spewing mercury) and eating highly processed foods, including meat and dairy products from animals who have been shot full of goodness-knows-what, and we're worrying about whether or not too much HANDWASHING is causing our allergies? Yipes.

end of rant.

8/15/2005 3:45 PM  
Blogger Moreena said...

Liz, yes, I also think that pollutants could be causing our immune systems to behave strangely. But there is some good evidence and reasoning behind the hygiene theory. I certainly don't think it is the absolute answer (and this is the conclusion reached by the general overview article that I linked). My only concern with the hygiene theory is that it may lead to dangerous behavior (turning down antibiotics that your doctor prescribes, although let's hope that doctor is also being careful in prescribing them only for clear cases of bacterial infection and not for every last illness, or purposely exposing your child to germs/illness, or deciding not to wash your hands after the toilet).

By the way, Annika's liver disease (biliary atresia) is one of those "cause unknown" diseases, despite lots of research. Environmental pollutants have also been suggested as a possible cause (although it's not the most popular theory).

8/15/2005 3:55 PM  
Blogger Mike said...

Interestingly enough, my allergy is actually to a food additive/preservative, but they can't identify which one, partly because the type of reaction I'm having makes it damn hard to test for, but also because all food additives which have been approved as "safe" by the FDA are more or less unavailable for allergy testing, and are only sporadically indicated on labels. Why? Because they've been approved as safe. Hence the BBQ ribs that almost killed me.

So I'm very sympathetic to the idea that chemicals and food processing are a big factor in the growth of allergies in the developed world.

On the other hand, I've had a doctor try to prescribe me antibiotics for a head cold. When I asked what good antibiotics would do against a head cold, he admitted that he prescribes them for just about everybody, since people feel like the doctor's visit was a waste if they don't walk out the door with a bottle of pills.

Yikes.

In the end, I take the middle-ground position that stress is worse for me than most anything out there, and I take as good care of myself and my family as I can without causing myself too much of it. And I die a little bit inside every time I remember that I can never eat spare ribs again. That's a harsh sentence for a Kansas City boy.

Oh, and the devil-take-the-hindmost position might be a good way to raise sheep, but it's lousy for people. Not only is it, well, kind of evil, but it doesn't even work. Darwinian principles stopped applying to the human race as a soon as we started teaching our children. Now, our biology develops on a Darwinian track, while our culture practices Lamarckian evolution.

8/15/2005 4:38 PM  
Blogger Moreena said...

This comment has been removed by a blog administrator.

8/15/2005 6:06 PM  
Blogger Moreena said...

Holy Smokes. So many typos above, I decided to delete and repost:

"Oh, and the devil-take-the-hindmost position might be a good way to raise sheep, but it's lousy for people."

Yes, you're right, of course. And I don't really think that anyone of conscience actually thinks this in regard to the hygiene theory, or any other theory for that matter. So my little summary ("let 'em get sick and the strong and lucky ones will survive and be stronger for it...") is certainly pushing things too far. However, I do think that people think a version of this, something like "let 'em get sick and they will survive and be stronger for it...", without really thinking of those who might not be able to deal with that particular illness.

I've certainly heard plenty of times from parents who are taking sick kids to school/daycare that it's not a big deal to expose other kids because it is so helpful to their immune system to get these colds. The fact of the matter is that most viral illnesses out there mutate so rapidly and so often that you are unlikely to be exposed to the exact same bug over again. So it's not like some sort of immune system test where you eventually get exposed to all the right things and then you're going to be healthy the rest of your life. (On the other hand, it is true that if you've been exposed to a close relative of that virus that you will not get *as* sick. So I'm certainly not saying there is no truth to this thinking. And there are some bugs, like chickenpox for example, that do give you immunity once you've had them - but also note that people who have had chicken pox are at risk of developing shingles later on in life, unlike those who were vaccinated.) I guess it seems to me that people take things a bit too far thinking that somehow spreading around colds is somehow good for kids.

But, again, I've wandered away from your points.

The real point here is : Mike, sorry to hear about the ribs. That's rough.

8/15/2005 8:05 PM  
Blogger Bettie Bookish said...

This is totally anecdotal from my own experience and the experiences I've heard from other parents, so take it all with a grain of salt.

My daughter spent her first 12 months in what most of us would call developing-world conditions. I'm not talking about refugee camps, exactly, but her particular social welfare institute in China was only a few steps above that.

I don't have a clear knowledge of her health history during those months, but I know that things like hand sanitizers weren't a part of it. Antibiotics are available and used - but the needles they put in the babies' heads may or may not have been new.

All in all, I suspect she was exposed to a great deal of bacteria, viruses and environmental pollutants.

And her immune system in the past year-plus has kept her free of illness, except for a very scary and very exhausting bout with foot-and-mouth disease.

But maybe her immune system is too good, as evidenced by the eczema we struggle to keep in check. In fact, among adopted Chinese children I've met, eczema seems almost as common as brown eyes.

I wonder if there could be a connection.

8/15/2005 11:23 PM  
Anonymous Beanie Baby said...

Liz--except that in many of hte most polluted countries, allergies and asthma are lower. I remember reading that after german reunification, east german kids had much fewer allergies than west german kids--but their environment was filthy in comparison.

No easy answers, eh?

Moreena, I love your post. I'll have to do some digging and get back to you.

8/16/2005 6:24 AM  
Anonymous Beanie Baby said...

Well, thank you. That is a very kind and polite way of saying that I often put my foot in it. :)

I often get the alcohol sanitizers and the antibacterial soaps confused, but in this case I really did mean the alcohol ones. Unfortunately I cannot find a trace of the source I saw, which means I might have imagined the whole thing, but: the story I read/heard about/invented wholecloth discussed that one factor in the spread of SARS within hospitals during the Toronto outbreak was related to the use of hand sanitizers. Not that they were ineffective or didn't kill germs, but that the nurses had a false confidence in their effectiveness and would often a) use them improperly and b) use them instead of washing hands. The study-which-has-disappeared concluded that regular hand-washing according to the accepted standards would have been more effective.

When Frances was born, she was in the hospital for 8 days during a flu outbreak, and so the old SARS stations were brought out again--tables of purell in the front lobby with a sign that said YOU MUST USE THIS BEFORE GOING IN. But--NO Instruction. Nothing that said, dime-sized amount and rub until dry. In that case, is it doing any good?

I don't think the sanitizers are a bad idea when used properly, meaning not only that the technique (rubbing until the sanitizer dries completely) is well-performed but also that it doesn't replace hand-washing. Obviously in your family it doesn't. But it would make me nervous if, say, my child's preschool had hand sanitizers near the washrooms and promoted them in place of handwashing, especially if they didn't take the time to teach the children how to use it properly. I would be worried that the use of the Magic Technical Fix would inspire a sense of false confidence in the kids and in the workers, and that other important hygeine issues would be neglected because hey--they've got hand sanitizers! And then it wouldn't make things better, and might make things worse.

I noticed, for instance, that in the study you linked to they not only provided hand sanitizer to the families but also educational materials on hygeine and how to use the sanitizers. This is crucial. Hand sanitizers, like regular soap and water, must be used properly. When not used properly, they can be worse than using nothing because people think they are cleaner than they are, and act that way. It would be interesting to see a study that compares infection rates between families provided with sanitizers and instructions on using them vs. families provided with soap and paper towels and instructions on using them.

You and Anni are in a special situation, and you know better than anyone what's required to safeguard her health. But I would think that for regular kids, good instruction on proper handwashing with soap and water would be better than providing bottles of hand sanitizer.

On the hygeine hypothesis--personally I'm all in favour, as it allows me to be a lax housekeeper and claim it's for Frances's health. ;) I try to strike a balance. I'm not exposing her to germs needlessly b/c I want to "strengthen her immune system"--she's got all her shots and I try to keep her away from infections when I can. But I don't try to keep her in a hygeine bubble either. I don't bleach the floors, I don't use antibacterial anything anywhere, I don't use a million chemicals in cleaning the kitchen or the bathrooms, I don't keep her inside away from pollen and grass. Things are tidy and neat and relatively clean, but according to the standards of Good Housekeeping, alas, I am a slob. I try to expose her to the things I'm allergic to in the hopes that this will help her learn the difference between "bad bugs" and "other stuff".

8/16/2005 7:49 AM  
Blogger Mike said...

The picture I can't get out of my head is of my best friend's son, cheerfully chewing on the dog's skeezy tennis ball, while we all run toward him in slow motion, screaming "NOOOOOOO!" True story, and guaranteed to cause a conniption in susceptible people.

It's a fairly well accepted principle in medicine that infections strengthen and train our immune system, except when they don't. And then there are the many, many things we don't understand, but which might very well have their roots in some infectious agent someplace, combined with genetic predisposition, and environmental factors. Even, perhaps, schizophrenia.

There's a lot we don't know.

We do know, though, that overuse of antibiotics has led to the development of microbes that are damn hard to kill using traditional methods. That's a pretty big problem.

The trick, I think, is to find a middle way.

And thanks for the kind words. Not eating ribs sucks, but not breathing sucks worse. Last time I had a reaction, I passed out on my way to the epi-pen. Luckily Christie woke up and administered it for me.

8/16/2005 8:37 AM  
Blogger Moreena said...

Andrea -- Yes, of course you're right that the proper use of hand sanitizers is an important issue that should be taught, especially in a hospital environment. However, it is true that hand sanitizers are *tons* easier than soap and water to use properly (see Liz's list of her daycare's protocol with the soap).

You are also right that the critical factor in the result of the study I linked to may have been the hand-cleaning educational materials rather than the hand sanitizer. It would be interesting to see this study repeated with one group receiving information on proper hand washing with soap and water, and the other group getting the same instructions, plus instructions on using hand sanitizer to supplement their routine. That would really tell us something about the use of sanitizer.

Also, my compliment to you was not meant to be backhanded. I truly do love the curiosity that pushes you to explore issues without hesitation.

Mike - I agree.

8/17/2005 9:48 AM  
Blogger Phantom Scribbler said...

Very late to this party, but here is my two and a half cents. One of my grandmothers died of an allergic reaction when my mother was a child. For the record, this grandmother was born and raised in wartime Transylvania, which, I am willing to bet, was not the cleanest place in the world. The hygiene hypothesis is still just that -- a hypothesis, and one which has not at all been proved.

Most of my grandmother's descendents, including me, have severe allergies. Being the paranoid parent that I am, I've done fairly extensive research on what literature there is about the possible causes of allergic disease, and the short answer is: they have no. frickin. idea.

Really. No clue. There are some explanations that may fit one aspect of allergic disease -- like eczema -- but appear to be totally unrelated to other aspects, like asthma. I've seen one study that correlated the use of infant vitamins with the development of food allergies. Vitamins!

Until they know, they just don't know. I say this as a parent who is ridiculously lax about a lot of hygiene: handwashing is a good thing.

8/20/2005 10:12 AM  
Blogger jon said...

Looking at asthma info online today while my son coughs I came across this post. Does anyone know a good asthma site to help?

Thanks

10/02/2005 8:26 AM  

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