Physicians caring for asthmatics should consider exercise-induced wheeze (EIW) an indicator of risk for urgent medical visits, according to new research which found that “EIW may contribute to the disparities in urgent medical visits for asthma between high- and low-income neighborhoods.

For the study, researchers collected caregiver-completed surveys reporting on 195 middle-income children with asthma who lived throughout New York City. Overall, 43% of the children had experienced EIW one or more times in the previous year. Those living in asthma hotspots were twice as likely to experience symptoms after exercise and more likely either to visit their doctor in a hurry or to go to an ER because of breathing problems.

After determining that asthma was no more severe in low-income, high-asthma neighborhoods, the researchers focused on one particular manifestation of the disease: rapid airway constriction brought on by exercise.

However, researchers were unable to identify why asthma hotspots have higher rates of EIW. While inadequate use of a bronchodilator inhaler prior to exercise was part of the story, it didn’t fully explain the findings. Allergens and air pollution related to fossil fuel burning were not found to be factors. Neither were differences in physical activity, obesity, or neighborhood conditions such as the number of parks.

“Exercise-induced symptoms may identify a distinct population of asthmatics with causes for their exacerbations yet to be determined,” said lead author Timothy Mainardi, MD, past fellow at Columbia University Medical Center and currently in practice at Hudson Allergy. “The important lesson is that with greater awareness and treatment, we can hope to prevent those unscheduled visits to the doctor and trips to the ER.”