Prophylactic inhalation therapy in preschool children with asthma

Respiratory diseases are a major cause of morbidity in preschool children. Confronted with young children with respiratory symptoms the physician faces many uncertainties regarding the diagnosis, treatment and prognosis, namely: • labelling of chronic and recurrent respiratory symptoms and defining 'asthma'; • the natural course of respiratory symptoms and the relation with future asthma; the effectivity and side-effects of anti-asthma treatment, for both relief and prophylaxis; • the feasibility of and compliance with prophylactic inhalation therapy. In studying effectivity of anti-asthma drugs, the investigator has additional problems: • symptoms as outcome measure; • the difficulty of conducting clinical trials, finding the appropriate setting and considering the ethical aspects of research in young children. In this chapter, the background of these uncertainties for physicians and investigators will be explored further. The place of sodium cromoglycate in prophylactic therapy will be discussed in detail because it is the main focus of the studies in this thesis. The results of this research will be presented in the following chapters together with results of studies on preschool asthma in general practice and on the feasibility of and adherence to maintenance inhalation therapy.