There is growing interest in the pronounced variability in the incidence and severity of chronic respiratory diseases such as Asthma, observed to occur in any particular patient over a given period of time. It is now known that acute exacerbations are multi-factorial in origin, with pollution, allergens and viruses all implicated, and effective treatment requires a similarly complex approach that addresses each of the component causes. In this new volume, leading authorities review what is known of these causative factors and the mechanisms by which they exacerbate the symptoms of pulmonary disease both singly and in combination. The authors evaluate the individual efficacy of current treatments in the light of this knowledge and present new recommendations for formulating effective therapeutic regimens. Short Contents