ABSTRACT
Asthma is a chronic disease characterized by episodic reversible airway obstruction. The aetiology remains uncertain, but it is likely to be a combination of genetic and environmental factors. Airway narrowing can be precipitated by many factors which provoke bronchoconstriction, mucosal oedema and mucous plugging. Asthma is a major cause of paediatric morbidity, affecting at least 1020% of children in the UK. Acute asthma is one of the most common paediatric emergencies.
