It's believed that six million American children suffer from asthma. However, new research shows that some children who have been diagnosed with condition may actually suffer from a vocal cord affliction.

Doctors at Columbus Children's Hospital believe that at least some children diagnosed with asthma may actually suffer from vocal cord dysfunction (VCD), a sudden, abnormal narrowing of the vocal cords during inhalation causing obstruction of the airflow, and characterized by a noise that can mimic the sound of wheezing.

A VCD attack can easily be mistaken for an asthma attack though it does not respond to asthma medications, according to the findings published in the July issue of Pediatric Pulmonology.

Researchers performed a clinical research study in the hospital's emergency department to try to identify adolescents who had findings suggestive of VCD compared to an acute asthma attack.

The year-long study, conducted between Feb. 2005 and Feb. 2006, included patients 12- to 21-years-old who suffered from acute episodes of respiratory distress.

“Both asthma and VCD are very common, and emergency departments across the country are seeing more and more kids with these kinds of symptoms,” said Dr. Karen McCoy, chief of Pulmonology at Columbus Children’s Hospital and a faculty member at The Ohio State University College of Medicine, in a news release. “While they may appear similar to parents, the conditions act differently and must be treated differently. It is important that parents, coaches and family doctors are aware of the differences.”

According to the study, 12 of the 17 adolescents seen by the hospital over the study period for difficulty breathing, but with high to normal oxygen levels, were found to have evidence of VCD. This led to a change in the therapy for these patients.

Doctors used a method called spirometry to help differentiate VCD from asthma attacks.

“Our study suggests that if more emergency departments made use of the spirometry test, it could cut down on the number of kids who are misdiagnosed and potentially hospitalized,” said Muffy Chrysler, a co-author on the study and an asthma coordinator in Respiratory Care at Columbus Children’s Hospital.