Inflammation in childhood asthma and other wheezing disorders.

It has become clear in the last few decades that the primary underlying pathology of asthma is airway tissue inflammation. In asthma, airway remodeling occurs during chronic inflammation, even in very young children. One of the key goals in treating asthma is to identify those young children with an asthmatic phenotype and initiate early treatment to avoid irreversible airway remodeling. Distinguishing asthma from other conditions that induce wheezing is a daunting but critical step in the appropriate treatment of asthma. In some children, hallmark mediators of inflammation, such as increased eosinophil levels, may distinguish asthma from other causes of wheezing, such as viral infections. Although progress has been made in the differential diagnoses of asthma in young children, more research is needed to define unique markers for distinguishing asthma from other respiratory conditions that produce wheezing.