Asthma: Grown-ups have it, too

Content provided by the Faculty of the Harvard Medical School

Asthma: Grown-ups have it, too

The condition is sometimes misdiagnosed in adults, although proper treatment could spare many bouts of coughing and wheezing.

There’s been so much medical concern and media publicity about childhood asthma that you might think the disease is only a problem for children. But you’d be wrong. Although asthma usually begins in childhood, it’s very much an adult disease. In fact, asthma may affect as many as 10% of people over age 65; that would make it more common in the elderly than in children.

Adult asthma sometimes goes untreated, or is treated in the wrong way, because so many other medical conditions can cause shortness of breath and wheezing. But when correctly diagnosed, asthma can be effectively controlled with treatments tailored to the needs of the individual patient.

The telltale twitch

The symptoms of asthma often come and go, and the frequency and severity of attacks vary tremendously. Some asthmatics cough and wheeze and feel short of breath nearly every day. Others breathe just fine between the occasional attacks.

This intermittent quality is one aspect of asthma that makes the disease different from other lung conditions like emphysema (a loss of lung elasticity) and chronic bronchitis (inflammation of the bronchial tubes), which involve persistent damage to lung tissue. Asthma needs a trigger. For many people, it’s a type of allergic response to the substances in the dust that wafts through the air — the specks of pet dander, pollen, mold spores, and so on. But people without allergies can have asthma that is triggered by aspirin, exercise, cold air, a respiratory infection, or air pollution.

If asthma is a possibility, “twitchy” is a term you’re likely to hear along the diagnostic pathway. That doesn’t mean anything is literally twitching; it’s a way of referring to the sudden narrowing of the lung’s airways. Emphysema and chronic bronchitis can also narrow airways, but it happens more gradually and the symptoms are pretty constant.

But the diagnostic boundaries aren’t always so neat and tidy. Someone with chronic bronchitis may develop twitchy airways after a respiratory infection and be described as having “chronic asthmatic bronchitis.” And untreated asthma may reshape airways so they’re permanently narrowed.

Confused with heart failure — and vice versa

Heart failure and asthma are easily confused, so there are incorrect diagnoses — in either direction. Normally, oxygen-rich blood drains from the lungs into the heart. When people have heart failure (often called congestive heart failure), their weakened hearts don’t fill or empty properly. This creates back pressure, so the lungs fill up with fluid. As a result, people cough and wheeze and may seem to be asthmatic, when it’s heart failure causing the problem. One study from a cardiac center found that about one in every five patients with heart failure was originally misdiagnosed as having asthma and treated accordingly, sometimes for years, before the situation was rectified.

It’s never too late

Asthma doesn’t usually start in adulthood. About three quarters of the time, symptoms are experienced before age seven. But many people grow up with a fairly mild case that went undiagnosed for decades. For reasons not completely understood, some teenagers outgrow their childhood asthma. So if your asthma suddenly comes on, perhaps you had it as a child and outgrew it, only to have the condition return years later.

This is not to say that adults don’t develop new cases of asthma. Perhaps there’s some new irritant in the air. Or your airways have become more reactive with age. If you’re a smoker or smoked in the past, the damage to your lungs’ airways may have made them more sensitive (more twitchy) to triggers that didn’t bother them before. Some adults get asthma after a nasty respiratory infection; the cold goes away but the asthmatic tendencies linger on. There are undoubtedly genes that make some people especially vulnerable to asthma, although clearly inherited cases usually surface in childhood.

Unfortunately, outgrowing adult-onset asthma isn’t an option. Once you have it, you’ll have it for the rest of your life, but it can be controlled with treatment.

Although childhood and adult asthma are fundamentally the same disease, the triggers tend to be different. For adults, it is less likely to be one of the classic allergens like pet dander. Air pollution, bad indoor air quality at work, and secondhand tobacco smoke can pose big problems for adult asthmatics. Sufferers may need to seek out smoke-free businesses or sit as far away from any smoking section as possible. They’ll probably also want to steer clear of places heated by wood stoves.

Diagnosis: Breathe in, blow hard

There’s no blood test for asthma. Instead you should expect a thorough physical exam with an emphasis on listening to your lungs. Be prepared to give your doctor a detailed history of your symptoms. A chest x-ray won’t show the characteristic airway narrowing, but your doctor may order one to rule out advanced emphysema, other chronic respiratory conditions, congestive heart failure, or lung cancer.

Two types of pulmonary function tests — spirometry and the peak flow meter — can help determine how well your lungs are working and whether the airway narrowing is asthma-related.

Spirometry measures how much air you can breathe out and how fast and forcefully you can exhale it. Your test results are compared to those of a person with healthy lungs who is the same sex and about the same age and height. If your airways are narrow because of asthma, the air will flow out relatively slowly.

Usually you’ll be given a fast-acting bronchodilator — a standard treatment for asthma — and asked to repeat the spirometry test. If the test result improves, your breathing difficulty was probably caused by asthma. That’s a critical part of the diagnosis: treating symptoms as if they are caused by asthma and seeing if they improve.

The peak flow meter is another way to measure how fast you can empty your lungs. It’s a simple device that costs $20–$30. You blow into the tube-like meter as hard as you can to get a measurement (in liters per minute) of how fast you can push air out of your lungs. The peak flow meter doesn’t measure the total capacity of your lungs, so it can’t always distinguish between asthma and other respiratory diseases such as pneumonia, lung scarring, or lung collapse. But for some people, it may be enough to make a diagnosis, especially if your doctor also observes an improvement with the bronchodilator test. Asthma patients often monitor their condition themselves with a peak flow meter.

Asthma: The airways narrow in two ways

Treatment: Bronchodilators and anti-inflammatories

The on-again, off-again nature of asthma is a challenge for both patients and their doctors. The threat of an attack is always there. Yet without symptoms as reminders, it’s not easy to stay vigilant with medications.

Airway narrowing from asthma has two causes: contraction of the muscles that ring the bronchial tubes (which leads to constriction) and inflammation (which results in swelling of the walls of the airways). The muscle contractions can be treated with fast-acting bronchodilators, including albuterol (Proventil, Ventolin), metaproterenol (Alupent), and pirbuterol (Maxair). Long-acting versions include salmeterol (Serevent, Advair Diskus) and formoterol (Foradil).

You may have heard about the debate over salmeterol. Research reported in 2003 suggests that it may increase the number of serious asthma attacks, especially in African Americans. But the FDA has allowed the drug to stay on the market, and most asthma doctors believe it’s useful as long as you take it absolutely as directed and in combination with an anti-inflammatory medication. That’s the reason-to-be for Advair Diskus, a combination of salmeterol and the anti-inflammatory drug fluticasone. If you’re taking salmeterol, stay in touch with your doctor in case there are new warnings.

Asthma inflammation is treated with a number of anti-inflammatory medicines, including the newer inhaled corticosteroids, such as beclomethasone (QVAR), budesonide (Pulmicort), and fluticasone (Flovent). Other anti-inflammatory treatments include corticosteroid pills and injections, mast cell stabilizers, and leukotriene blockers. Immunoglobulin E (IgE) blockers, such as omalizumab (Xolair), are a new anti-inflammatory treatment for allergy-based asthma.

If you’re taking asthma medications along with pills for other conditions, you must follow your doctor’s instructions carefully because of possible drug interactions. Blood pressure and cholesterol medications aren’t usually a problem. But beta blockers can be because they can narrow lung airways. Those being treated for asthma who are taking a beta blocker should discuss with their doctor whether they should be taking one of the “selective” beta blockers — atenolol (Tenormin) or metoprolol (Lopressor), for example. The selective beta blockers don’t affect the lungs as much as regular beta blockers.

Last updated:	August 21, 2006