It’s the middle of the night. Your child’s coming down with a cold so you tucked her in early. Suddenly you’re awakened by her harsh, dry cough and gasps for air.

New parents might call the doctor. Experienced parents recognize that distinctive “seal-like” bark as “the croup.” They haul out the humidifier.

But a new study shows a humidifier or vaporizer… which adds tiny droplets of water vapor into the air… may not do the trick. Treating croup with humidity is popular because it’s thought to soothe swelling and decrease phlegm, but it’s not scientifically based.

The most common acute upper-airway obstruction in children, croup is caused by a virus that inflames the tissues around the larynx. It’s diagnosed in up to five percent of children under six and sends one percent to the hospital.

Canadian researchers looked at one-hundred-forty children ages three months to ten years who were brought to the E-R and diagnosed with moderate or severe croup.

The children received one of three treatments for thirty minutes… either room-air humidity blown in tubing aimed at their face, or a mixture of high or low humidity and oxygen by mask.

The findings? One-hundred-percent humidity coupled with oxygen wasn’t any better at treating croup than the other two approaches tested.

Doctors say croup often goes away on its own. But if this is your child’s first case of croup, see your doctor to confirm it. And, at the first sign of any breathing trouble, call nine-one-one.