New research indicates that asthma in many adolescents is not likely to involve inflammation of the airways and therefore should not be considered an allergic disease.

For the study, investigators assessed clinical characteristics and inflammatory markers in 77 adolescents with asthma and compared them with those found in 68 healthy participants aged 12 to 17 years. The presence of asthma did not appear to involve eosinophils or neutrophils, specific types of white blood cells that are present in higher concentrations in response to inflammation.

"These findings are important since current treatment is largely directed at reducing inflammation and may explain why in some asthmatics, asthma medication is less effective," said Dr. Jeroen Douwes, senior author of the Respirology study. "If asthma can occur without any airway inflammation then other treatments may need to be developed for those asthmatics."