Defining and describing airways obstruction in children.

The two most common diseases with airway obstruction from pre-school age are asthma and cystic fibrosis (CF). Airway diseases in infancy will not be discussed. For reasons of simplicity, asthma is defined as the complex coexistance of one or more of the symptoms wheeze, breathlessness, cough, mucus hypersecretion, which are either chronically or intermittently present and which are generally triggered by viral infections, allergens, pollutants (cigarette smoke), exercise, sudden changes in temperature of the inspired air etc.