Figure 1.

Longitudinal asthma cohort studies have identified genetic background, family history of asthma and atopy, infections early in life, allergic disease, and lung function as risk factors for persistent symptoms. In children and adolescents, male sex is one of the factors associated with remission of symptoms, while in adulthood female sex is associated with new-onset disease. The archetypical phenotype of persistent asthma that starts in childhood and is permanently present throughout life represents only a minority of patients with asthma. Reprinted with permission from Reference 6. AHR = airway hyperresponsiveness.