ALLERGIC FACTORS ASSOCIATED WITH THE DEVELOPMENT OF ASTHMA AND THE INFLUENCE OF CETIRIZINE IN A DOUBLE-BLIND, RANDOMIZED, PLACEBO-CONTROLLED TRIAL - FIRST RESULTS OF ETAC(R)

There is a common progression known as the allergic march from atopic dermatitis to allergic asthma. Cetirizine has several antiallergic pro perties that suggest a potential effect on the development of airway i nflammation and asthma in infants with atopic dermatitis. Methods. Ove r a two year period, 817 infants aged one to two years who suffered fr om atopic dermatitis and with a history of atopic disease in a parent or sibling were included in the ETAC(R) (Early Treatment of the Atopic Child) trial, a multi-country, double-blind, randomised, placebo-cont rolled trial. The infants were treated for 18 months with either cetir izine (0.25mg/ kg b.i.d.) or placebo. The number of infants who develo ped asthma was compared between the two groups. Clinical and biologica l assessments including analysis of total and specific IgE antibodies were performed. Results. In the placebo group, the relative risk (RR) for developing asthma was elevated in patients with a raised level of total IgE (greater than or equal to 30 kU/l) or specific IgE (greater than or equal to 0.35 kUA/l) for grass pollen, house dust mite or cat dander (RR between 1.4 and 1.7). Compared to placebo, cetirizine signi ficantly reduced the incidence of asthma for patients sensitised to gr ass pollen (RR = 0.5) or to house dust mite (RR = 0.6). However, in th e population that included all infants with normal and elevated total or specific IgE (intention-to-treat - ITT), there was no difference be tween the numbers of infants developing asthma while receiving cetiriz ine or placebo. The adverse events profile was similar in the two trea tment groups. Discussion. Raised total IgE level and raised specific I gE levels to grass pollen, house dust mite or cat dander were predicti ve of subsequent asthma. Cetirizine halved the number of patients deve loping asthma in the subgroups sensitised to grass pollen or house dus t mite (i.e. 20% of the study population). In view of the proven safet y of the drug, we propose this treatment as a primary pharmacological intervention strategy to prevent the development of asthma in specific ally sensitised infants with atopic dermatitis.