Inhaled corticosteroids and the natural history of Asthma

Inhaled corticosteroids (ICS) are the most potent form of controller medication available for the treatment of childhood asthma (1). When administered regularly and in adequate doses, ICS significantly improve symptoms, bronchial hyperresponsiveness to methacholine and other stimuli, and quality of life in school-aged children and adults with persistent forms of the disease (2, 3). ICS have also been shown to be effective in controlling symptoms in preschool children, but effects are usually not as dramatic and consistent in this age group as they are in older children (4 - 6). What may cause these differences in the efficacy of ICS in infants and young children with respect to that in older children will be discussed later in this chapter.