You may think that people get croup only in books, but no—children today still get this infection of the airway. It's not nearly as dramatic as it was 100 years ago, though, and now croup's distinctive barking-seal cough is usually caused by a fairly mild viral infection and goes away on its own. But even mild croup is no darn fun for a sick kid or the parents who have to see their child suffer it. For several groups, drugs known as corticosteroids are effective. A group of Canadian researchers tested one of them, the drug dexamethasone, on children with mild croup.

What the researchers wanted to know: Does dexamethasone help children with mild croup?

What they did: The researchers randomly assigned 720 children with mild croup to get dexamethasone in cherry-flavored syrup or cherry-flavored syrup with a dab of distilled water; neither the doctor nor the parents knew whether the child was getting the drug or the fake. A research assistant called parents 1, 2, 3, 7, and 21 days after treatment. They asked whether the sick child had to go back to the doctor and how fast the symptoms went away.

What they found: Only 7 percent of children who got dexamethasone had to go back to the doctor within a week, while 15 percent of children who took placebo had to go back. In the first 24 hours after treatment, children who'd taken dexamethasone were doing better than children who'd taken the placebo, and their parents were less stressed, too.

What the study means to you: More than 75 percent of children were better by day 3 whether or not they'd gotten the drug. But if they'd had the drug, the symptoms went away faster. The researchers point out that even though doctors know that mild croup is no big deal and will go away on its own, parents get very anxious about it and may bring a child with croup to the emergency room more than once during the same short illness. From that point of view, they write, it's a lot less misery and expense for everyone to give the child a dose of corticosteroid.

Caveats: The researchers say no one has looked at the long-term effects of giving children oral corticosteroids for croup, but they write that studies in children with asthma have shown that the drugs don't affect bones or hormones.

Find out more: The National Library of Medicine's Medline Plus has information on dexamethasone.

Read the article: Bjornson, C.L., Klassen, T.P., Williamson, J., Brant, R., Mitton, C., Plint, A., Bulloch, B., Evered, L., and D.W. Johnson for the Pediatric Emergency Research Canada Network. "A Randomized Trial of a Single Dose of Oral Dexamethasone for Mild Croup." New England Journal of Medicine. Sept. 23, 2004, Vol. 351, pp. 1306–1313.

Abstract online: http://content.nejm.org