Tài liệu Báo cáo y học: "Why are some children with early onset of asthma getting better over the years" -ane

In the last decades, the prevalence of childhood asthma has been increasing in many parts of the world, especially in developed countries (1). Particu-larly in the USA and mainly in urban areas it has almost reached epidemic levels (2), most marked in low-income urban communities (3). Only recently, this global increase of childhood asthma prevalence has shown signs of levelling out or even in some Western countries reversing (4).