Humidifiers are often the first line of defense for parents trying to help a miserable child with a cold or flu. But raising the humidity in a child's room may not do much good.
That's the surprising news from Ameet Daftary, an assistant professor of pulmonology at the University of Utah School of Medicine. Shots called Daftary to get the scoop on a report he authored in this week's Pediatrics, about a 6-month-old child who developed serious lung problems after his parents put an ultrasonic humidifier in his room to ease cold symptoms.
The boy's now doing fine, but Daftary wrote up the incident because he thinks that the lungs of babies may be more vulnerable to the chemical particles kicked out by ultrasonic humidifiers than parents and doctors realize.
But the big surprise was the researcher's statement that no one has shown that humidifiers actually do relieve cold symptoms. "It's just anecdotal evidence," Daftary told Shots. "There isn't any clear evidence that this works, one way or another."
Say what? Millions of parents have been buying humidifiers, and struggling with cleaning them, not to mention buying expensive filters and antimicrobial additives, and humidifiers don't do a lick of good? Do tell.
Parents of young children have very few options for cold medications, Daftary says, which may encourage parents to use humidifiers. Pediatricians routinely recommend them, too, along with saline nose drops, to treat colds. What's more, people generally feel most comfortable with air at about 40 percent humidity, and in centrally-heated houses winter humidity can drop down into the teens. So a sick child may indeed feel better in a more humid room. There's just no scientific proof for relief of symptoms.
Back to the news: is there proof then that humidifiers pose a health risk? This new report involves just one child, and millions of small kids probably get the humidifier treatment when they're sick. So the risk is probably low. Still, ultrasonic humidifiers like the one involved in the Pediatrics study have been under suspicion before.
In the early 1990s, investigations by the Environmental Protection Agency and the Consumer Product Safety Commission in the early 1990s found that the machines can spew out bacteria, fungus, and tiny particles of heavy metals into the air, but determined that the humidifiers don't pose a "serious health risk." The EPA recommends that people clean humidifiers regularly, and use distilled water to reduce the risk.
The parents of the Utah child who suffered rapid breathing and low blood oxygen for weeks had used distilled water, so that wasn't the culprit. The doctors who treated the child think the illness may have been a reaction to chemicals in the white dust generated by the humidifier, which contained calcium, magnesium, fluoride, nickel, and other minerals. The child's symptoms went away after he was treated with intravenous steroids.
It may be that the doctors just haven't gotten around to rigorously testing the effect of humidifiers on children's cold symptoms, and the anectodal evidence is right. But it could also be that parents are going to a lot of trouble that really doesn't help much.