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.

Swear Off Toilet Paper With This Bidet Toilet Seat That's Easy to Install and Costs Less Than $100

Tushy
Tushy

The recent coronavirus-related toilet paper shortage has put the spotlight on the TP-less alternative that Americans have yet to truly embrace: the bidet.

It's not exactly a secret that toilet paper is wasteful—it's estimated to cost 437 billion gallons of water and 15 million trees to produce our yearly supply of the stuff. But while the numbers are plain to see, bidets still aren't common in the United States.

Well, if price was ever the biggest barrier standing in the way of swearing off toilet paper for good, there's now a cost-effective way to make the switch. Right now, you can get the space-saving Tushy bidet for less than $100. And you'll be able to install it yourself in just 10 minutes.

What is a Bidet?

Before we go any further, let’s just go ahead and get the awkward technical details out of the way. Instead of using toilet paper after going to the bathroom, bidets get you clean by using a stream of concentrated water that comes out of a faucet or nozzle. Traditional bidets look like weird toilets without tanks or lids, and while they’re pretty uncommon in the United States, you’ve definitely seen one if you’ve ever been to Europe or Asia.

That said, bidets aren’t just good for your butt. When you reduce toilet paper usage, you also reduce the amount of chemicals and emissions required to produce it, which is good for the environment. At the same time, you’re also saving money. So this is a huge win-win.

Unfortunately, traditional bidets are not an option for most Americans because they take up a lot of bathroom space and require extra plumbing. That’s where Tushy comes in.

The Tushy Classic Bidet Toilet Seat.

Unlike traditional bidets, the Tushy bidet doesn’t take up any extra space in your bathroom. It’s an attachment for your existing toilet that places an adjustable self-cleaning nozzle at the back of the bowl, just underneath the seat. But it doesn’t require any additional plumbing or electricity. All you have to do is remove the seat from your toilet, connect the Tushy to the clean water supply behind the toilet, and replace the seat on top of the Tushy attachment.

The Tushy has a control panel that lets you adjust the angle and pressure of the water stream for a perfect custom clean. The nozzle lowers when the Tushy is activated and retracts into its housing when not in use, keeping it clean and sanitary.

Like all bidets, the Tushy system takes a little getting used to. But once you get the hang of it, you’ll never want to use toilet paper again. In fact, Tushy is so sure you’ll love their product, they offer customers a 60-day risk-free guarantee. If you don’t love your Tushy, you can send it back for a full refund, minus shipping and handling.

Normally, the Tushy Classic retails for $109, but right now you can get the Tushy Classic for just $89. So if you’ve been thinking about going TP-free, now is definitely the time to do it.

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Do Dogs Get Headaches?

Even without raging benders, dogs might still get headaches.
Even without raging benders, dogs might still get headaches.
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Like babies, dogs can be hard to read in the medical ailment department. Are they listless because they’re tired, or because they’re sick? What’s behind their whining? And can they suffer that most human of debilitating conditions, the headache?

Gizmodo polled several veterinarians and animal behavior specialists to find out, and the answer seems to be a resounding yes.

Although a dog can’t express discomfort in a specific way, particularly if it doesn’t involve limping, animal experts know that canines that have diagnosed brain tumors or encephalitis can also be observed to have a high heart rate, a sign of physical pain. According to Tim Bentley, an associate professor of veterinary neurology and neurosurgery at Purdue Veterinary Medicine, administering painkillers will bring a dog’s heart rate down. If signs of physical distress also decrease, a headache was likely involved.

Unfortunately, not all dogs may offer overt signals they’re feeling some brain pain. According to Adam Boyko, an associate professor of biomedical sciences at the Cornell University College of Veterinary Medicine, dogs instinctively try to mask pain to avoid showing weakness.

Ultimately, dogs have many of the same central neural pathways as humans, which can likely go awry in some of the same ways. But the kind of persistent headaches owing to head colds or hangovers are probably rare in dogs. And while it goes without saying, they definitely don't need any of your Advil.

[h/t Gizmodo]