Who's at Risk for Asthma Relapse?
1 in 3 Childhood Cases Reappear by Age 26
Mar. 7, 2005 -- When asthma vanishes, it's not necessarily gone for good. One out of three kids who beats asthma by age 18 gets it again by the time they're 26.
But there's a little fine print to those newly reported numbers. On the bright side, asthma may be less harsh if it returns in young adulthood. But asthma's encore may be hard to predict.
Taking common-sense precautions could help. Don't smoke, avoid allergens, and choose jobs that don't raise your asthma risk.
"By not smoking and avoiding occupations that increase the likelihood of developing asthma, patients can help protect themselves from asthma relapse," says Malcolm Sears, MB, ChB, FRCPC, in a news release.
Most jobs are probably fine, so job applicants shouldn't hear "no, thanks" just because they once had asthma, says Sears, who worked on the new study and is on staff at Canada's McMaster University.
Asthma Is Becoming More Common
Asthma is on the rise worldwide. It affects 15% to 20% of the population in Western countries, say Sears and colleagues.
Cases can vary in severity. For many people, asthma is mild, but it can still hinder quality of life and the ability to work, the study shows. The researchers say that some authorities even recommend that people without symptoms, yet who have a history of asthma, should be screened out on the grounds of increased risk.
Asthma symptoms aren't always constant. Up to a third of patients get at least a four-year break from it by age 26, say the researchers, citing another study.
Asthma's Unwelcome Return
Sears and colleagues studied 868 kids born in New Zealand in the early 1970s. They used questionnaires, allergy screenings, and breathing tests to check airflow to see which kids got asthma. The kids were screened at ages 9, 11, 13, 15, 18, 21, and 26.
By age 15, nearly a fifth of the group had doctor-diagnosed asthma. Of those kids, 68 said their asthma was gone by age 18.
But eight years later, many had asthma again. Asthma returned in 24 participants by age 26. That's about one in three people whose asthma had been in remission.
New asthma cases were rare at age 26. It occurred in only about 9% of all participants. The asthma was usually milder than before in the 24 participants whose conditions returned. Mild asthma is often easily controlled, write the researchers.
Avoiding Asthma's Return
It's hard to forecast who will get asthma again. But it wouldn't hurt to avoid cigarette smoke and allergens.
"The likelihood of relapse is unpredictable," write Malcolm Sears, MB, ChB, FRCPC, and colleagues.
Relapse in early adulthood was more common when participants had:
- Allergies to house dust mites, grass, cats, dogs, and mold
- Poorer lung function at age 18
- Increased response, at age 21, to a test used to determine if your child has asthma. The methacholine test is given in an attempt to change the airflow in your lung.
- Increased responsiveness to treatment with a medication used to open constricted airways seen in asthma (bronchodilator) at age 21
Nearly half of the relapse group smoked, compared with a third of those who didn't have a relapse. Because of the small number of participants in the study those findings weren't significant, the news release says.
The study appears in the March issue of the journal CHEST.