Steroid drugs, one of the most common treatments for young children prone to wheezing and colds do not help and may even be harmful, according to new research.

Two different studies were published in the January 2009 New England Journal of Medicine. One study, conducted in Britain looked at preschoolers who were hospitalized with a wheezing attack and treated with the steroid prednisolone. The study showed that the children stayed hospitalized just as long as other children who were given dummy pills.

The second study focused on children in Canada who had previous wheezing trouble and took the steroid fluticasone as a preventative measure. That study showed modest improvement in breathing but the side effect of possible stunted growth outweighed the benefits, researchers said.

Wheezing, a high-pitched whistling noise as a person exhales, occurs when air struggles to get through narrowed airways. Parents often bring their children to emergency rooms thinking their kids can't breathe.

Dr. Bradley Chipps, an allergy specialist in Sacramento, California, told the Associated Press that the research "gives us good information that what we've been doing doesn't work."

"It gives us a lead to pursue a safer alternative," he said. Dr. Chipps is on the allergy and immunology executive committee of the American Academy of Pediatrics and had no role in the study.