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Allergies Health Center

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Carbon Dioxide Gas May Treat Nasal Allergies

Study Shows CO2 Gas Treats Sneezing, Itching, and Runny Nose Better Than a Placebo

Rinsing the Nose With CO2 continued...

People in the study were randomly assigned to receive either carbon dioxide gas or a placebo. Those in the carbon dioxide group were further divided into groups who got either low or high doses of the gas for either 10 seconds or 30 seconds.

People in the treatment groups were asked to wear a nosepiece that was attached to a cylinder that was filled with compressed gas. A regulator controlled the flow of gas, so that study participants got either 5 milliliters or 10 milliliters of gas per second for either 10 seconds or 30 seconds in each nostril.

The placebo group wore the same device for either 10 seconds or 30 seconds with no gas flowing through it.

Study participants were advised that they might or might not feel the flow of the gas. Some participants in the placebo group reported feeling gas flowing through their noses, while some in the CO2 group said they couldn't feel anything.

All groups reported an improvement in their symptoms.

The placebo group reported that their nasal symptoms improved about 3 points, on average, on a 20-point scale.

The carbon dioxide groups reported that their symptoms improved by 3.7 to 4.7 points on a 20-point scale.

Only one treatment group reported relief that was significantly better from the placebo group, however. That was the treatment group that received 10 milliliters of CO2 per second for 10 seconds per nostril.

Symptoms that were most improved included itching and watering of the eyes, eye redness, sneezing, and a runny nose.

There was little change in nasal congestion.

More Research Needed

Experts say that despite its promise, carbon dioxide isn't yet ready for general use.

"The good news for patients is that there's ongoing research into new and novel ways to treat this chronic condition that affects a third of our adult population," says Stanley M. Fineman, MD, a practicing allergist in Atlanta. Fineman is also president-elect of the American College of Allergy, Asthma & Immunology.

"The nice thing about this potential treatment is that it is not a medication," he tells WebMD, "It's not a chemical."

Even if a CO2 treatment comes to market, the relief it offers is likely to be brief.

Fineman says it wouldn't replace disease-modifying treatments like allergy shots or longer term controllers like inhaled steroids.

"This would be more of a reliever for breakthrough symptoms," Casale says. "I think it could be equated maybe to how some people use over-the-counter antihistamines if they're having symptoms."

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