A chemical messenger in the blood can tell doctors whether the cause of an asthma attack is a virus or an allergy. The finding may one day lead to a new treatment for most severe asthma attacks. It would be an important advance. An asthma attack associated with a viral respiratory infection can begin rapidly and be quite severe. The study found that virus infections are behind nearly 80% of severe asthma attacks. In the vast majority of cases, the culprit is the common cold virus, which typically shows symptoms such as fever, cough, and upper airway symptoms such as nasal congestion. Asthma is a disease of the lower airways, making breathing difficult. Peter G. Gibson, MBBS, of John Hunter Hospital in New Lambton, Australia, and colleagues report the findings in the August issue of the American Journal of Respiratory and Critical Care Medicine.
