Clinical phenotypes of asthma

The classic phenotype of IgE-mediated asthma starting in childhood is now clearly defined. However, many other phenotypes of asthma in childhood as well in adulthood are being recognized. In particular, asthma starting in adulthood and noneosinophilic asthma constitute an important part of the adult asthma population, and are still poorly defined. A precise definition of these asthma phenotypes is urgently needed because they are likely to be associated with different genotypes, responses to treatment, and prognoses.