When Amy Hendricks took her daughter Olivia to the doctor because of a bad cough and funny-sounding breathing, she expected to hear that her 1-year-old probably had a cold. "But after the pediatrician said she might have asthma, I burst into tears," says Hendricks, of Chambersburg, Pennsylvania. "It's awful to see your child in distress and then hear that she could have breathing problems for the rest of her life."A Growing Health Threat
Olivia -- now age 5 and requiring treatment only for the occasional episode -- has plenty of company: Almost 5 million American children live with asthma, which accounts for almost 3 million doctor visits and 200,000 hospitalizations every year, according to the American Academy of Allergy, Asthma & Immunology. With asthma, the smooth, sensitive muscles surrounding the bronchial airways become inflamed easily. Set off by a trigger -- say, a virus, smoke, or exercise -- the muscles swell, causing a cascade of unhappy events. Inflammation makes the muscles spasm, tightening the airways, while the bronchial tubes' protective lining produces mucus. The result is tight, clogged airways that lead to coughing, wheezing, and breathing problems.
More and more children are living with these so-called twitchy lungs. Asthma cases in kids climbed an average of 4.3 percent a year between 1980 and 1996, and the condition is considered to be the most common serious, chronic childhood condition, according to the Centers for Disease Control and Prevention. Why is asthma, like other allergic diseases, on the rise? No one knows for sure, but theories abound -- notably, the hygiene hypothesis: With fewer germs to fight in today's sanitary environments, the body's hypervigilant but misguided immune system instead attacks harmless substances, such as dust and pollen.
But some experts wonder whether living in more hygienic conditions explains today's rash of cases. "We've been living cleaner for 50 years, and the asthma increase occurred very quickly and recently," says pulmonologist Chris Harris, MD, assistant professor of pediatrics at Vanderbilt Children's Hospital, in Nashville. "Likewise, though some theorize that pollution plays a role, our air is cleaner than it was 20 or 30 years ago." Also, he adds, increased awareness and recognition of asthma may explain why more kids are diagnosed nowadays.Increased Risk for Asthma
But will your child be among them? If a parent has asthma, a child's risk might be as high as 20 to 25 percent, says Andy Liu, MD, associate professor of pediatrics at National Jewish Medical and Research Center, in Denver. "Allergies and eczema in early childhood also increase asthma risk, especially in babies and toddlers with recurrent coughing or wheezing," adds Dr. Liu.
Researchers are uncovering other possible links to asthma, including taking antibiotics before age 1 and living near a major road. Even having a high birth weight (generally, more than 8.8 pounds) raises the risk by 20 percent, say University of California at San Francisco researchers in a recent review of 12 studies. And the increased risk for overweight school-age kids is even higher: 50 percent. The researchers speculate that there may be a dietary connection -- perhaps overweight kids eat fewer foods, such as fish, with anti-inflammatory fats -- or that excess pounds place extra pressure on airways. "We can't yet say that high weight actually causes asthma, but the two seem to be linked," says the study's lead author, Valerie Flaherman, MD, a senior pediatrics fellow at UCSF.