It doesn't help to give steroids to children who are wheezing from viral infections, and the medications may be overused in preschoolers, doctors say.

In Wednesday's online issue of the New England Journal of Medicine, researchers concluded that corticosteroids, the most common treatment for wheezing, is ineffective at best.

'It is disturbing to contemplate how many unnecessary courses of prednisolone have been given over the years, in good faith, because we all assumed that preschool children are little adults.'— Dr. Andrew Bush

Attacks of wheezing caused by viral infections in the upper respiratory tract are common in preschool children between the ages of 10 months and six years. About one-third of Canadian children will wheeze — when they have colds.

Wheezing — a high-pitched whistling noise as a person exhales and air tries to get through narrowed airways — is not only troublesome for parents, but it is also a burden to pediatric emergency rooms. Doctors have to try to figure out which patients actually have asthma, a cold, or are wheezing for no particular reason.

"If you think of a cat when they purr when you pet them or something, that's what it sounds like," said Dellanee Kahlke of Edmonton. She gives her son Jacob a steroid inhaler when he has a cold and wheezes.

Preschool children who go to the hospital with such symptoms are commonly treated with a short course of prednisolone — a steroid that is used to reduce inflammation in the airway and that is very effective in treating attacks of allergic asthma in older children and adults.

In the latest published research, one study looked at using inhaled steroids for prevention, the other examined higher doses to get kids out of hospital faster.

The conclusion: more is not better. In fact, doctors now worry steroids may be overused in preschool children.

Rethink pratice

"For the mild to moderate, maybe inhaled steroids or oral steroids in the emergency isn't the best approach and that we need to really think about what we're doing," said Dr. Piushkumar Mandhane, a professor of pediatric respiratory medicine at the University of Alberta, who is among the hundreds of researchers worldwide searching for a better treatment.

Doctors said there is no simple solution, since no two children can be treated in exactly the same way.

In the Canadian study, 129 children aged one to six years who had previous wheezing and took the steroid fluticasone as a preventive measure showed modest improvement after 10 months, but the side effect of possible stunted growth outweighed the benefit, the team concluded.

"It is disturbing to contemplate how many unnecessary courses of prednisolone have been given over the years, in good faith, because we all assumed that preschool children are little adults," Dr. Andrew Bush of the Royal Brompton Hospital in London wrote in an accompanying editorial.

The British study, led by the University of Leicester, looked at 687 children aged 10 months to five years who were hospitalized for wheezing and were randomly given prednisolone or placebo treatment.

Wait-and-see approach

There was no significant difference in how long the children spent in hospital: 11 hours for the drug group compared with 14 hours for the placebo group.

"It is clear that on the basis of these two studies, current practice must change," Bush said.

It would be better to take a wait-and-see approach with wheezing children, said pediatrician Dr. Sami Bahna of the Louisiana State University Health Sciences Center in Shreveport.

"The majority will do well without intervention," Bahna said.

The Canadian study was funded by GlaxoSmithKline PLC, which makes Flovent nasal spray, a brand of fluticasone. Lead author Dr. Francine Ducharme of the University of Montreal reported receiving research grants from Glaxo and other drug makers.

The British research was paid for by the non-profit Asthma UK. Several of the authors reported receiving fees and support from various drug makers that make asthma medication.

With files from Associated Press