Insights into early treatment of mild asthma: do inhaled corticosteroids make a difference?

Approaches to the management of moderate-to-severe persistent asthma in both children and adults are widely accepted but the treatment of mild persistent asthma remains controversial because of the lack of agreement on what constitutes mild asthma and whether regular treatment is required at all. Recent evidence indicates that 'mild asthma' may not be as benign a condition as was widely believed and should be treated to improve asthma control and to prevent the significant burden of exacerbation and progression of disease. This is supported by compelling evidence from histologic and clinical studies that have attributed irreversible pathologic and functional airway changes to consequences of persistent airway inflammation and under-treated asthma. This article focuses on the rationale of early treatment of mild persistent asthma, and discusses the various findings from the largest randomized, early-intervention trial with inhaled corticosteroids as regular treatment in patients with asthma of recent onset--the START (inhaled Steroid Treatment As Regular Therapy in early asthma) study. A brief review of the background of the natural history of asthma, the findings from key longitudinal epidemiologic studies on disease progression in children and adults, and the effect of inhaled corticosteroids on this progression are included, to provide further insight into the impact of early treatment on asthma management guidelines.