Fri Apr 11, 2003
By Alison McCook
NEW YORK (Reuters Health) - New findings suggest that the first sign of asthma in a child may be simple throat-clearing.
University of Crete researchers looked at a group of children who, according to their parents, often cleared their throats.
About 58 percent of those children had not been diagnosed with asthma. Half of the undiagnosed children underwent tests of lung function, and the results showed that those youngsters did, in fact, have the condition.
"They all had a very mild form of asthma," Dr. Eva C. Mantzouranis told Reuters Health.
She suggested that parents of a child who constantly clears his throat for no obvious reason should consider getting the child tested for asthma, even if he has no other symptoms of the condition.
However, the typical questions doctors ask parents to determine whether children have asthma do not include throat clearing as a symptom, Mantzouranis noted. Children with asthma do better if they are treated earlier rather than later, she said, and doctors who don't ask about throat clearing symptoms may miss some early cases of the condition, she said.
"It is important to start treatment early, because the prognosis is better," Mantzouranis explained.
"I would definitely add that (question about throat clearing) to my standard questions for asthma," she added.
According to the American Lung Association, asthma is the leading serious, chronic illness in childhood, diagnosed in at least 7.7 million people younger than 18 in the US alone.
While wheezing and coughing are considered common symptoms of asthma, other symptoms that also signal the disease has arrived may be less recognized, Mantzouranis and her colleagues note.
In an interview, Mantzouranis explained that she began to suspect that throat clearing could be a sign of asthma when some parents of children being treated for asthma reported that their children had also stopped constantly clearing their throats, a habit they had thought of as a "tic."
To determine whether throat clearing was a sign of early asthma, the authors looked at questionnaires given to the parents of 2,609 children aged between three and five years old who attended a daycare center. The questionnaires asked parents about typical symptoms of asthma and included one additional query: "does your child have a habit of clearing his or her throat often?"
Almost 18 percent of the children had been diagnosed with asthma during the previous year, and another 24 percent had been told they had the disease prior to the previous year, Mantzouranis and her colleagues report.
Parents of 106 children said they were frequent throat clearers, 61 of whom had never been diagnosed with asthma, nor had any symptoms of the condition.
To test whether these supposedly asthma-free children did, in fact, have the disease, the researchers measured lung function in 30 of the youngsters old enough to perform the test.
This test revealed that these children, on average, had reduced lung function. After doctors gave them treatment for asthma, however, both their throat clearing and lung function improved.
Seeing an improvement in symptoms after receiving asthma medication is "consistent with the diagnosis of clinically unrecognized asthma," Mantzouranis and her colleagues write.
Mantzouranis explained that children with asthma have sensitive airways that react poorly to different stimulants. In many children, this exposure leads to coughing or wheezing. But in others with a less severe form of the condition, their reaction is not strong enough to cause a cough or wheeze, and exposure to a stimulant may result in simple throat clearing, she said.
SOURCE: The New England Journal of Medicine 2003;348:1502-1503.