Asthma is the most common chronic condition of childhood. The prevalence and severity of childhood asthma have increased substantially in recent years. Age-related differences in diagnostic and therapeutic considerations in childhood require special attention. Asthma can begin in infancy, although rarely in the first few months of life. Wheezing is a common symptom encountered in infancy through the first 2 to 3 years of life and may be a transient phenomenon in this age group.
Many children develop persistent or recurrent wheezing, i.e., asthma.
Persistent asthma that begins early is likely to be more severe. Atopy in the child, parental atopy or asthmatic history and maternal smoking are risk factors for persistent and recurrent asthma. Low lung function and maternal smoking are risk factors for transient wheezing. The history and physical examination, the mainstay of diagnosis in all age groups, present special problems in infants and young children. The diagnosis and estimation of asthma severity must depend more on the history and response to therapy as assessed by inconstant third-party observations than more continuous as well as more objective assessments possible in the older child and adult.