Asthma in infants and children.

Asthma is the most common chronic illness in childhood and represents a significant burden to health care and educational systems. Between one quarter and two thirds of childhood asthma cases persist into adulthood. Childhood asthma may be particularly difficult to diagnose because of the high prevalence of episodic wheezing and cough in childhood illnesses such as upper respiratory tract infections. National and worldwide guidelines for the management of asthma in children are continually being updated. These guidelines recommend first establishing a diagnosis and assessing the severity of disease, initiating pharmacologic therapy based on symptoms and lung function, and adjusting doses and agents as required based on the level of asthma control. Inhaled corticosteroids are the cornerstone of long-term asthma management in children of all ages. Recent research efforts have focused on ways to improve inhalant drug delivery to the lungs and minimize oral and systemic bioavailability so as to improve the therapeutic benefit:risk ratio.