Global Asthma Network Phase I Syria asthma surveillance and the impact of the war.

Background: Asthma is the most prevalent chronic respiratory disease (CRD) in children. It causes extensive morbidity and mortality worldwide. Since the International Study of Asthma and Allergies in Childhood (ISAAC Phase III 2001-3), there have been no worldwide standardised surveys of prevalence and severity of asthma in school children.