Last updated: Feb 02, 2012
allergic-asthma
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What is allergic asthma? Of the more than 22 million adults and children in the United States who have asthma, at least half of adults and about 80% of children have allergic asthma. In any kind of asthma, the lungs overreact to triggers by 'tightening up' airways, which causes persistent coughing (particularly at night), wheezing, shortness of breath, and difficulty breathing.

But in the case of allergic asthma, those triggers are substances—animal dander, dust mites, pollen, mold, cockroach proteins, or other allergy-causing particles—that don't bother most other people.

Non-allergic asthma triggers, on the other hand, can include exercise, cold air, pollution, and stress. Many people have a combination of both types, and the treatments are often similar for both—mostly to ease the swelling and inflammation in the lungs and open up the airways.

So why does it matter what's causing your symptoms? Well, the more you know about your triggers—allergic or not—the better your chances of avoiding breathing problems.

James Thompson's graduate studies in biopsychology required him to spend a lot of time working with rats. Already plagued by seasonal asthma attacks due to a pollen allergy, he became sensitized to rodents too. His lung function became so compromised that he nearly died of pneumonia at age 25. (Respiratory infections can make asthma worse.)

Two decades later, Thompson is still allergic to rodents, but he's also learned a whole lot more about how to cope with his allergic asthma.

"Over the past 10 years I've just been trying to understand the triggers more," he says. Thompson has found he has a combination of both allergic and non-allergic asthma. The Maplewood, New Jersey-based non-profit manager knows auto exhaust is a problem for him too. Now he tries to make sure his home is free of dust-collecting clutter and he'll cross the street to avoid inhaling bus exhaust. "When you're in your 20s you really don't notice, you don't make all these connections with your environment."

What's causing your asthma?
The first step to figuring out how to treat your asthma is to realize that you have it. That's harder than it sounds. Do you have persistent nighttime coughing or shortness of breath? It's easy to dismiss it as due to a cold, lack of exercise, postnasal drip, or just about anything else other than an allergy to the pet sleeping in your bedroom.

Many people with allergic asthma attribute their symptoms to a garden-variety cold, says John Winder, MD, an allergist based in Toledo, Ohio and the chair of the American College of Allergy, Asthma and Immunology's Nationwide Asthma Screening Program. The free screening, offered at about 200 sites across the United States, includes a breathing test and an interview with an asthma specialist.

To date, more than 100,000 people have been screened through the program, Dr. Winder notes, and half of them were referred to a specialist for further diagnosis.

If you do indeed have allergic asthma, the next step is to find ways to limit your exposure to the allergens that affect you. "Avoidance is the best defense," Dr. Winder says.

To nail down the specific triggers, it's best to see an allergist, says Robert A. Nathan, MD, director of the Asthma and Allergy Associates and Research Center in Colorado Springs, Colo. While primary care doctors may suspect that a person has allergic asthma, they typically do not delve deeper to confirm the diagnosis with a skin or blood test.

Skin prick testing is the most common way to determine if someone is allergic to a particular substance. This involves placing a tiny amount of a specific allergen (like pollen protein) into a person's skin. If redness or swelling develops within 20 to 30 minutes it indicates an allergy to the substance.

Some allergens are easier to avoid than others, and sensitivity varies widely among individuals. For example, some people can nip a pet allergy in the bud by living in an animal-free home and taking medication for their symptoms when they visit a friend or family member who does have pets.

"Other people are so reactive that they just have to go out to dinner with people who have dander on their clothes to have a reaction," Dr. Nathan notes.


How to beat allergens at home
You can do several things at home to limit your allergen exposure. First, clear out dust traps like wall-to-wall carpeting and clutter. If your basement is damp and musty, install a dehumidifier. Leaving a light on in the basement can also be helpful, according to Dr. Winder, because mold needs both dark and dampness to grow. Keeping the air in your house relatively dry will also help control dust mites.

Your best bet if you're allergic to animal dander is to have a pet-free home (unless it's a dander-free pet, like a snake), but this isn't always realistic. If you can't bear to part with a furry pet, try keeping your pooch or kitty in a specific part of the house (not your bedroom). Many people find it helpful to put cheese cloth over bedroom radiators or vents to prevent allergens from circulating. (Find other tips in How to Reduce Pet Allergens at Home.)

And if you're thinking about getting a pet, the consensus is that there really is no such thing as a hypoallergenic dog or cat, although some breeds are thought to be better than others.

If you're still suffering from symptoms despite your best efforts, you may want to consider allergy shots, which have about an 85% effectiveness rate at decreasing symptoms. But keep in mind it requires a long-term commitment. It can take up to five years of once-a-week to once-a-month visits with your allergist to get the injections.

The best way to handle dust mite allergies? Special dust mite covers for your pillows and mattress. The mattress cover never needs to come off the bed, Dr. Winder says. Wash sheets at least once a week in water that's at least 130 to 140 degrees Fahrenheit. And when you dust, use a damp cloth; a dry one will simply send dust mites floating.

If pollen is your foe, try to avoid going out at certain times of day when pollen counts are high, Dr. Winder advises. "Early morning and early evening, late afternoon, are two prime times for getting exposed to the pollens," he says.

And keeping the area outside your home tidy—by eliminating piles of rotting leaves or other debris on your lawn, in your gutters, or anywhere else nearby—can also help keep outdoor mold under control.

Thompson and his family recently moved from a house with wall-to-wall carpeting on the second floor and a musty-smelling basement to a house with area rugs only, and no musty basement smell. "I've noticed a difference since we moved here, I just breathed a little easier."

For Thompson, paying attention to his symptoms and his environment has made a big difference in how he feels. "I think there's a lot of little things you can do. I think you just need to be more aware of your surroundings and what your environment is like and how clean it is."

How to treat it
When it comes to treatment of allergic asthma, inhaled corticosteroids are the backbone of therapy because they reduce lung inflammation, according to Dr. Nathan.

If inhaled corticosteroids don't keep symptoms under control, your doctor may prescribe a long-acting beta agonist or an anti-leukotriene modifier, like Singulair.

Anyone with asthma should also keep a short-acting beta agonist on hand for emergencies. These "rescue inhalers" can ease asthma symptoms fast. They're meant to be used only occasionally, unless you're using them to prevent exercise-related asthma symptoms. Using them more than a couple of times a week indicates that asthma is poorly controlled and other medications are needed. Overuse of beta-agonists can actually make it more difficult for the airways to relax on their own.

Medications like Allegra can help keep seasonal allergy symptoms under control. Xolair (omalizumab) is a new drug that works by tying up the antibodies that cause allergies, but it is only used in patients with severe disease because of the cost.

In addition to paying close attention to his asthma triggers, Thompson keeps a rescue inhaler on hand. He only uses his rescue inhaler a couple of times a month, at most. And during pollen season, he tracks pollen counts online so he knows what to expect on a given day, and takes Allegra to cope with his symptoms.

One of Thompson's former doctors prescribed him several medications for asthma symptoms, and then kept upping the dosage when they didn't help. The medications made it hard for him to sleep and gave him nightmares, so he decided to try get a better handle on his symptoms himself (and find another doctor).

"I think that there's a lot of little things you can do," he says. "I think you just need to be more aware of your surroundings and what your environment is like and how clean it is."