- So like, keep your kids in the mud. Is that what I'm hearing right now? Get your kids dirty. Like give them mud baths? (bright music) Dude, there are so many categories of allergies. Give it to me in list form. That's how I like to see things, lists. Boom, boom, boom. - Boom, boom, boom. - Go. - So the main categories, food, is a big category. Seasonal allergies, another category. - Ragweed. - Ragweed. You proud of it. Like, ragweed. - Ragweed. - Another big one I see all the time in the clinic are drug allergies, especially to antibiotics. Also insects people think about bees and dust mites, but did you know cockroaches are a big cause of allergy responses and asthma? - I didn't know, but that does not surprise me. - [Alok] Pets, like dogs and cats are also a huge cause of allergies in children, and well, everyone. - Saliva and dander, right? - Yeah. - I was allergic to my my Great Dane's saliva. The Great Danes have like lots of drool and he would shake his head and it was just like like slap me and I'd break out into giant whelps as soon as it hit. And my mom would be like, "Well, wash your face then." Then that was like, that was it. - Mold is another category. We can't forget things that come in contact with your skin. You know, certain soaps, lotions, detergents even metals like titanium, nickel. People can get allergic symptoms from all these different mechanisms. An allergic reaction essentially happens when the body perceives a harmless substance as a dangerous invader and goes and makes these proteins or antibodies called IgE. IgE then sees a foreign invader and goes to other cells which release chemicals that cause those allergy symptoms you all know and hate. If a child has an allergic reaction to a particular food, you may think that's the first time he or she has ever seen the allergen, but we know it's at least the second time the child's body has seen the allergen because the IgE antibodies are already there. (glass clinking) Scientists are still trying to understand the basis for allergies and why some people have a really bad response to some foods or allergens and others don't. We know that it all stems from IgE which was designed to protect us. IgE antibodies protected our ancestors from worms, parasites, and environmental threats every day, perhaps even a lethal snake which might be lurking in a greenhouse, in a grocery store who knows? But somehow, the IgE has now turned into this mechanism that can sometimes take a harmless invader and give us this expulsion response. So basically, an allergen will come in your body and IgE will be like, "Get out!" And that's why allergies come with things like sneezing, hives, vomiting, anything to eject what was once a worm or parasite, and now could be a simple food allergy. So in the end, there's a lot we don't understand. And it might just be a glitch in the immune system which was designed to protect us, but is now calling harmless substances, dangerous invaders. - What about maybe keeping things too clean has something to do with the allergies? Like what too clean, how could you be too clean? You know? - You're referring to hygiene hypothesis. - That is exactly- - You knew that! - What I'm referring to. - It seems counterintuitive because you want to keep your kitchen clean. You want to keep your kids clean. But what hygiene hypothesis is basically getting at is that when children are very young, their exposure to the world of dirt, microbes, that's bacteria, viruses, you know, their environment can help prime their immune system and teach their immune system what's harmful and what's not and prevent future allergies. - Okay. - And there's actually some studies to support this, including one in the United States which found that the Amish community had a lower rate of allergies in comparison to other communities including other farming communities. You could even take that and look at it on a grander scale because some data suggests we have higher rate of allergies in industrialized developed countries like the US of A than they do in developing countries. - Okay. - So hygiene hypothesis is probably a thing. - So like keep your kids in the mud, is that what I'm hearing right now? Get your kids dirty. Like give them mud baths, roll 'em around. - This is why we say it's a hypothesis. Because it's an idea, and we think that in the future, we might be able to look at the Amish culture or look at hygiene hypothesis and kind of give parents recommendations. Because as of right now, it's like use your maternal common sense. Don't your kids touch raw meat, for example. (buzzer buzzes) Okay. Hey, you know what? Maybe if they get their hands dirty, they were playing sandbox, it's not gonna be the end of the world. - Okay. Or like if they eat scrap a food off the floor? - This isn't evidence-based either, but a scrap a food, almond. Oh no, it's on the floor. One, two, three, four, five. I did it. - Yum! - I did it. Don't tell anyone. Don't show anyone. - Don't try this at home. - We're renegades. - We're professionals. - We're rebels. - Almond, almond. Almond. - I don't know what an almond. - An all-mond is when something bad is happening. It's a foreboding of something to come. - This is debate, though. - This is about almond. - This is about an almond. (bright music)