Stroking a cat can sometimes trigger an asthma attack.

If these situations sound familiar, you may be among the growing number of kids with a lung disorder called asthma.

“It’s very common for kids to have this,” says Andy Liu, a childhood asthma-and-allergy researcher at the National Jewish Medical and Research Center in Denver. And, he says, asthma is becoming more and more common.

Between 1980 and 1996, the number of asthma cases doubled in the United States. Today, more than 20 million adults and about 9 million kids have asthma, according to the Centers for Disease Control and Prevention.

“When I was a kid, one or two kids in our class had it,” Liu says. “Now, five or six kids in a class do.”

While the exact reason for the increase remains a mystery, scientists are discovering patterns and zeroing in on explanations. New tests for the disease are in the works. And treatments have improved tremendously.

“We used to think of kids with asthma as being limited,” Liu says. “That’s changed in the last 15 years. We believe most kids [with asthma] can live normal lives now.”

Lung passages

Inside your chest, your lungs are like a tree with hollow branches. These branches serve as airways. When you take a breath, air moves into these branches. It then passes through the thin lining of the lungs and delivers oxygen to your bloodstream.

Air travels along passageways in the lungs to deliver oxygen to the blood.

During an asthma attack, a thick, slippery substance called mucus blocks the lung passages, swelling occurs, and lung muscles squeeze on the airways. Breathing becomes difficult.

Such episodes don’t usually happen out of the blue. At least half of the people who suffer from asthma have allergies that can trigger an attack, says Sam Arbes. He’s an epidemiologist at the National Institute of Environmental Health Sciences in Research Triangle Park, N.C.

Allergies occur when your immune system, which is designed to protect your body against infection and disease, overreacts to cat hair, mold, pollen, dust, or other foreign substances. Such substances are called allergens.

Some people merely sneeze and sniffle when they’re exposed to certain allergens. People with asthma have a much stronger reaction. In some cases, they end up in the hospital.

To figure out whether an increase in allergens is responsible for the increase in asthma, Arbes and his colleagues recently collected dust from 831 homes throughout the United States.

“We found cat and dog allergens in every home we sampled—even in homes that didn’t have cats or dogs,” Arbes says. “A lot of homes had levels high enough to cause allergies and asthma in people.”

Pollutant triggers

There’s more to the story than Fluffy’s or Fido’s hair, however. Scientists know that for some people with asthma, the disorder has nothing to do with allergies. Asthma triggers can include, for example, exercise, cigarette smoke, perfumes, and cooking odors.

This image, magnified 500 times, shows pollen from a variety of common plants, including the sunflower, morning glory, hollyhock, lily, evening primrose, and castor bean. Some people are allergic to certain types of pollen.

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Scientists are, however, pretty confident that allergies do make asthma worse, Arbes says. But, he adds, “we don’t know if exposure [to allergens] is what actually causes people to get asthma in the first place.”

To understand better why only certain people develop the disease, scientists are gathering information about the types of allergens that people are exposed to at home and about the types of allergies that they have. The work is part of a huge, long-term study called the National Health and Nutrition Examination Survey (NHANES).

The study isn’t complete, but scientists have already identified some patterns. Kids living on farms get asthma less often than kids in cities do. Preschoolers in day care are less likely to have asthma than toddlers who stay home. And kids with older brothers and sisters have less asthma than kids who grow up alone.

Based on these trends, a theory called the “hygiene hypothesis” is gaining ground. The idea is that kids today encounter fewer types of bacteria than their parents did. That’s because they spend more time inside, use more antibacterial soaps, and take more antibiotic medicines.

As a result, the part of their immune systems that’s designed to fight infection doesn’t have enough to do, Arbes says. The part that’s involved in allergies takes over.

“The immune system gets fired up to fight allergens rather than pathogens or bacteria,” he says.

Better care

Figuring out what causes asthma might help researchers find ways to prevent it. Eventually, they hope to find a cure. Until then, doctors are working on managing the condition. And they’re getting pretty good at that, Liu says.

Asthma hasn’t kept Jerome Bettis of the Pittsburgh Steelers from becoming a great athlete.

Hello Pittsburgh

Identifying and avoiding asthma triggers is one good preventive strategy. Medications can help manage the disease. Taken through inhalers, these medicines relax the lung muscles and bring immediate relief.

Meanwhile, a new test is coming that can diagnose asthma by sampling a person’s breath, Liu says. The test could lead to earlier diagnoses and better care.

“A lot of kids limit their activities because of asthma,” Liu says. “It doesn’t have to be that way.”

“If you have asthma, you should expect your life to be normal,” he adds. “You should be able to have minimal symptoms. You should be able to pick the sport of your choice and play at the level you want to.”

Have any doubts? Just look at football player Jerome “The Bus” Bettis of the Pittsburgh Steelers. Asthma hasn’t stopped him from being a great athlete.

American Academy of Allergy, Asthma & Immunology

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Comments:

Asthma is a very common disease. I know a few friends who have asthma. I
don’t have asthma but if I am not mistaken, asthma can be caused by many
different causes. Asthma can be caused by pollution. These friends I have live in
polluted streets. I know a girl that had asthma and she was cured.—Kimberly, 11

About 15 minutes later, my ears and armpits started to itch like crazy. A rash appeared on my arms. My lips and eyelids began to puff up. Pretty soon, I had to get off my bike because I was having trouble breathing. My chest felt constricted. My heart was racing. Itchy welts were popping up all over my body and inside my throat. My eyes were starting to swell shut.

A bee sting can cause a severe allergic reaction in some people.

Jack Dykinga/U.S. Department of Agriculture

In a panic, I grabbed my cell phone and called 911. I was having a severe allergic reaction to the bee sting. Without help, I knew there was a chance I could die.

“More people die from bee stings than from dog bites every year,” a doctor told me when I finally arrived in the emergency room after a nerve-wracking ambulance ride.

“Allergies in general are increasing in the population,” says Marc McMorris. He’s a pediatric allergist at the University of Michigan Health System in Ann Arbor.

More than 50 million people in the United States have serious allergies. And not just to bees. Food allergies cause even more deaths than bee stings, McMorris says.

Allergies to peanuts, in particular, are on the rise, along with reactions to ragweed, mosses, molds, cats, dogs, and shellfish. Name just about anything, and you’ll probably find someone allergic to it.

Puzzling details

As more and more people develop allergies, researchers are trying to understand what causes allergic reactions. Their hope is to find better ways of treating and preventing such reactions, which can sometimes be life threatening.

Many details remain mysterious, however. It’s not clear, for example, why different people react to different things, even within the same family.

“I treat a family with eight children, and they’re all allergic to some degree,” McMorris says. “Some have asthma, some have eczema, some have bee allergies. They’re all different. It’s just by chance that one person is allergic to one thing, while another person is allergic to something else.”

An allergy begins when the body encounters a foreign object, such as pollen, nut proteins, or bee venom. At first exposure, the body’s immune system reacts as if the object were a germ or parasite. It produces proteins called antibodies, which fight the intruder, or allergen.

Nearly 600,000 children in the United States suffer from an allergy to peanuts.

Jack Dykinga/U.S. Department of Agriculture

After your body makes the type of antibodies that trigger allergies, these antibodies stick around in your bloodstream as a sort of memory of the incident. After that, if you’re prone to allergies, repeated exposure to the same allergen can cause your immune system to freak out.

That’s exactly what happened to me. I had been stung by plenty of bees in the past. On those occasions, the area around the attack swelled up like a marshmallow in a microwave. This time, though, as soon as the bee venom entered my bloodstream, antibodies latched onto cells in my blood. These cells then released chemicals called histamines, which caused the swelling, itching, wheezing, and other symptoms. Severe reactions like mine are called anaphylaxis.

Now that the antibodies in my blood are primed to react to bee venom, every sting I get in the future will probably cause an even worse reaction.

In some ways, though, I feel lucky. At least, I’m not allergic to peanuts.

Troubling peanuts

People with supersensitive peanut allergies can have anaphylactic reactions just from being in the same room as peanut dust. My friend Karen, for one, can’t eat jelly if you used the peanut-butter knife to spread it.

“I’ve had kids react after being licked by someone’s dog who just ate dog food with peanut butter in it,” McMorris says.

All sorts of products, including many candies, contain peanuts or peanut oil. Even candy that doesn’t contain peanuts can cause an allergic reaction if it is made in a factory that also processes peanuts for other products.

Jack Dykinga/U.S. Department of Agriculture, Agricultural Research Service

More than 1.5 million Americans are allergic to peanuts. This number is growing, but nobody knows why. One possible cause is that pregnant women and nursing mothers may be eating peanuts before their babies have strong enough immune systems to cope with peanut proteins.

Peanut butter might be another big problem, suggests one recent study by the U.S. Department of Agriculture. The United States lags behind China and India in peanut butter production. But people in the U.S. have more peanut allergies. That might be because U.S. producers dry roast peanuts instead of boiling them, the new study suggests. Dry roasting appears to change the peanut protein into a form that triggers a more powerful allergic reaction.

Some scientists have been working to develop new strains of peanuts that are less likely to provoke an allergic attack. Other researchers are searching for new vaccines to prevent allergies from developing in the first place. One drug that shows promise was identified last year.

Being careful

For now, awareness and preparation are the best weapons, McMorris says. Some schools are banning peanut butter and jelly sandwiches in their lunchrooms. Allergic people are encouraged to carry special shot dispensers called epipens with them at all times.

I now have two epipens that I’ll jab into my leg next time I get stung. I also carry Benadryl, which blocks the action of histamines. The paramedics that rescued me after the bee sting put in a tube that delivered Benadryl straight into my vein. The hives and itching stopped almost immediately.

Even if you’ve never had an allergic reaction, it’s worth knowing how to recognize the signs. Allergies like mine can pop up at any time. Ingredients such as peanut dust can get into foods without warning, especially if factories or restaurants reuse dishes or utensils.

You might even be able to save the life of one of your friends. In one study, McMorris found that allergic kids, teenagers, and college students rarely carry epipens or tell their roommates or friends about their allergies. If you know what to look for, you can run for help in case of emergency.

“This is very serious business,” McMorris says. “You need to respect kids with food allergies. You have to take good care of your friends.”

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