What are the candidate groups for pharmacotherapeutic intervention to prevent asthma?

Despite the development of many new therapies for the treatment of asthma, the prevalence of this disease is still increasing in many areas of the world. Today no intervention is able to completely cure asthma but chronic therapies could decrease its severity. Moreover, asthma is one of the most common chronic diseases of childhood and its pharmacoeconomic burden is huge. Epidemiologic studies have identified some of the major factors involved in the pathogenesis and evolution of asthma. Several prevention programs have been developed in different countries with various success rates. Most of those interventions were based on allergen avoidance. From studies aimed at controlling early asthma and from epidemiologic data, we have learned to identify high-risk groups, e.g, the atopic child with allergic asthma, with a family history of asthma or allergy-related disease and early sensitization to aeroallergens. Only a few prospective studies aimed at preventing the onset of asthma have been published. With ketotifen, Iikura et al. could prevent the onset of asthma after a 1-year period in patients suffering from atopic dermatitis. Another study has been published by Bustos et al. concerning children with a family history of allergy and high total IgE levels. Those studies involved about 100 patients. No follow-up data has been published for either of them. Recently, the first results from the ETAC (Early Treatment of the Atopic Child) trial have been reported. This study involved 817 atopic children with atopic dermatitis and a family history of atopy: cetirizine halved the number of patients developing asthma in the subgroups (200 children) sensitized to house dust mite (51.5% versus 28.6%) or pollen (58.8% versus 27.8%). The optimal target for pharmaceutical intervention to prevent asthma would seem to be high risk patients: children with atopic dermatitis, a family history of asthma or atopic disease and early sensitization to aeroallergens. Primary prevention in whole populations (e.g. starting even before the onset of atopic dermatitis or allergen sensitization) does not at present appear to be a realistic approach.