Here’s What Happens to Your Body During Anaphylaxis

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iStock

According to the Centers for Disease Control and Prevention, allergies affect more than 50 million Americans every year—and anaphylaxis, the most severe allergic reaction, affects at least 1.6 percent of the general population [PDF]. Here’s the science of what happens to the body during anaphylactic shock.

ALLERGEN EXPOSURE

In a person with allergies, cells sometimes identify foreign but innocuous stimuli as major threats. Why some people are allergic to certain things while others are not is a mystery science hasn't yet solved, but we do know how it happens: through a process called sensitization.

Here’s how it works. When the body encounters a foreign substance, also called an antigen, immune system cells deliver some of substance's molecules to T-helper cells living in the lymph nodes. Those cells also bring along a type of molecule that informs a T-helper cell it’s time to stage an immune response. Known as a costimulatory molecule, it's necessary to activate any type of immune system reaction involving T cells, whether you have allergies or not.

Being exposed to an antigen "primes" a T-helper cell, turning it into a Th2 cell. Primed Th2 cells release proteins called interleukins, which do two things: First, they interact with another type of immune cell called B cells to produce infection-fighting antibodies that bind to mast cells, which contain chemical particles they'll release in the presence of an antigen. Second, the interleukins activate eosinophils, a type of white blood cell that discharges toxic substances to destroy invading cells (and, occasionally, host cells). In this process, the immune system identifies the "threat" and deploys cells prepared to fight it. The immune system's elevated level of awareness of and preparation against the antigen reclassifies the substance as an allergen—a considerably more dangerous threat.

Because an allergy only develops after this process, a person allergic to strawberries, for example, will only experience a reaction the next time they eat something containing strawberries. New allergies can pop up at any point in your life.

An immune system on allergies is a little bit like a brain that can't distinguish a piece of lint from a spider: unable to relax, constantly on guard against every potential threat. After initial exposure, the mast cells activated during the sensitization phase are still equipped with allergen-specific antibodies and remain combat-ready, prepared to respond immediately should a second exposure ever occur. If it does—and it probably will—here’s what you can expect to happen.

ALLERGIC REACTION

If two or more allergen molecules bind to a sensitized mast cell, the mast cell releases inflammatory mediators that produce an allergic reaction. These mediators include substances like histamine and more of the interleukins that, in turn, activate eosinophils, Th2 cells, and basophils (another type of white blood cell). In a non-allergic reaction, mediators produce helpful inflammation that prevents infection and initiates healing—but those same symptoms can be annoying and even dangerous when the immune system attacks an otherwise benign allergen. Mast cells also release leukotrienes, which recruit more immune cells to the area and speed up the reaction. That leads to what Stanford University researcher Tina Sindher calls a “‘chain reaction’ of allergic inflammation.”

With the release of histamine, you might experience both bronchial contraction—which makes it more difficult to breathe—and blood vessel dilation. The latter makes it easier for blood to flow to affected areas, but it also makes blood vessels more permeable, allowing blood to escape from the blood vessel walls and flow into the spaces between cells and causing swelling and hives.

For most, these symptoms are merely uncomfortable; they can occur as late as eight to 12 hours after initial exposure, long after the allergen is gone, and can be alleviated with an antihistamine like Benadryl. But for a person with severe allergies, a life-threatening allergic response can occur within minutes: Their airways will constrict so much they won't be able to breathe, and their blood vessels will be unable to contract, which can lead to a drop in a blood pressure and keep veins from getting blood back to the heart. The combination of airway constriction and blood vessel dilation can make it impossible for the body to supply enough oxygen to major organs—that's anaphylactic shock.

The only way to stop anaphylaxis in its tracks is with epinephrine, more commonly known as adrenaline. Adrenaline is a hormone naturally produced by the adrenal glands to help generate the "fight or flight" response in emergency situations. It works by constricting certain blood vessels, increasing blood pressure, and relaxing airways, counteracting all the reactions produced by histamines.

According to Sindher, it’s important to use epinephrine immediately if you're at risk for anaphylactic shock. “There’s a general belief out there that epinephrine should only be used in the worst-case scenario,” she tells Mental Floss. “In fact, most of the complications we see in food allergic reactions are due to delayed use in Epi. Antihistamines can be helpful in treating the symptoms of itching and congestion, but they do not help stop an allergic reaction.”

THE FUTURE OF ALLERGY TREATMENT

Researchers like Sindher are still trying to understand what causes allergies, and why the prevalence of food allergies has increased over the past few decades. Sindher’s main goal is to find new ways of treating (and hopefully curing) allergies. The most established technique (for food allergies, at least) is oral immunotherapy, where allergic individuals gradually eat more of their allergen until they can have small amounts without experiencing a reaction. That’s usually done extremely gradually, over the course of months or years, and always under the supervision of a certified allergist.

image of two epipens sitting on a desk
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Sindher says scientists are still testing other types of immunotherapy treatments and vaccinations in clinical trials: “A lot of research is going into trying to identify the causes so we can be successful in the prevention as well as treatment of food allergies.”

Until that happens, though, doctors say the best course of action is to be careful around allergens. Medications are useful and necessary, but prevention is the name of the game when it comes to allergies.

Fart All You Want—These 'Flatulence Jeans' Were Designed to Absorb the Smell

Shreddies
Shreddies

Like it or not, everyone farts, and they do it far more than you’d think. Healthy people pass gas up to 20 times a day, and, as we recently learned, even if you try to hold your farts in, they’ll come out one way or the other—possibly through your mouth. Depending on what you eat and where you pass it, that can get pretty smelly. That is, unless you’re wearing fart-proof pants. A UK-based company called Shreddies makes “flatulence filtering” jeans that promise to eliminate your worst smells before they can escape into the wider world, Business Today reports.

Shreddies products are lined with activated charcoal, a substance that’s great at absorbing odors and gases—so much so that it’s a go-to ingredient for home air filters and purifiers. According to Shreddies, the odor-absorbing qualities of the fabric last around two to three years, at which point you’d probably be buying new jeans, anyway.

A side view of a woman wearing fart-filtering underwear
Shreddies

You still have to mind your farts, though. The company says that to be effective, the jeans have to fit tightly against the skin, ensuring that your gas is absorbed directly into the fabric. “To avoid flatulence escaping around the filter we recommend that you stand with your legs together and try to let your wind out slowly,” the Shreddies website instructs (emphasis theirs). “When sitting, keep your knees together so that flatulence escapes through the carbon panel.” As long as the jeans fit correctly, the filter should absorb all the foul odors leaking out of your body.

The jeans, available for men and women, cost roughly $130 (£100) plus shipping, a price that probably seems worth it to the people in your life who have to deal with your noxious toots.

Not a jeans person? Fear not. The company also makes fart-filtering underwear and pajamas. There are gift options, too, for all of your favorite flatulence-prone friends.

[h/t Business Today]

How Microwaving Food Affects Its Nutritional Value

iStock/grzymkiewicz
iStock/grzymkiewicz

There’s probably no household appliance that sees more use than a microwave. For people who don’t have the time or inclination to prepare dinners from scratch or heat meals in a conventional oven, zapping food has become the ultimate method of time management in the kitchen.

Some people harbor the belief that a price has to be paid for that convenience—specifically, that food loses nutritional value by being subjected to a quick nuking.

The truth? Microwaving doesn’t harm a food’s nutrients. In fact, it may preserve them more than some slow-cook methods do.

The reason is found in how microwaves work. The appliances heat food by blasting it with waves of energy not unlike radio waves. These waves target water and other molecules in the food. Thermal energy quickly builds up, and dishes come out heated in a relatively short period of time. This process avoids two of the factors that can lead to nutrient loss: cooking duration and high temperatures. Typically, the longer and hotter food is cooked, the more its nutritional value dissipates.

The other advantage is that microwaves don’t require water for heating. If you boil broccoli, for example, the hot water allows nutrients to leach out of the vegetable. (While that makes for a good stock, your broccoli may be robbed of some of its healthy benefits.) A quick steam in the microwave leaves broccoli relatively intact.

That’s not to say that microwave cooking is superior to a stovetop. Cooking foods at reasonable temperatures and durations shouldn’t result in significant nutrient loss, though some is inevitable for any manner of cooking. But microwaving isn’t going to erase nutrients via some mysterious microwave alchemy, either.

[h/t CNN]

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