Childhood asthma is the most common chronic disease in the industrialized countries. It is chronic inflammatory disorder leading to recurrent episodes of wheezing, cough and breathlessness. In children 5-year-old and younger asthma has non-specific and diverse symptoms. A confident diagnosis of asthma is difficult particularly in infants. Diagnostic procedures encounter limitations in cooperation with young children.

Difficulties in diagnosis result in necessity of long-term follow-up, requiring the differential diagnosis and observing the child's response to bronchodilatator and anti-inflammatory treatment. Asthma treatment should be individualized. However, the evidence base for pharmacotherapy in small children is very limited. Comparing with adults the pharmacokinetics of anti-asthmatic drugs is also different.