Specific immunotherapy.

The prevalence of atopic allergic disease increased substantially towards the end of the 20th century and is set to rise further. This group of diseases now constitutes the most common cause of chronic ill health in industrialised countries. Despite considerable attention from the pharmaceutical industry, little progress has been made in the development of disease-modifying therapies. In contrast, recent activity has focused almost exclusively on treatment of symptoms (palliation) rather than cause. The failure of palliative approaches to address the issue of increasing incidence of disease is in evidence in the case of allergic diseases and is a continuing focus of concern. At present, the most frequently employed non-palliative form of disease-modifying therapy is specific allergen immunotherapy (SIT) in which increasing doses of whole allergen extract are administered in increasing dose in order to desensitise the allergic subject.