Risk factors for exacerbations and hospital admissions in asthma of early childhood

Hospital admissions and readmissions for asthma in early childhood remain causes for concern. The purpose of this study was to identify predisposing risk factors related to asthma exacerbations and precursors of hospital admissions in young children. Subjects were patients with doctor-diagnosed asthma from a clinical registration study, aged 0-4 years, and followed up for 2 years. Data from histories and laboratory tests for atopic status at initial presentation, and the patient's condition at visits over the 2-year follow-up period were evaluated. Exacerbation was defined as increases in cough and/or wheeze and/or breathlessness, increase in beta(2)-agonist use, and a clinical need for a short course of oral corticosteroids. Age groups 0-1 year and 2-4 years, based on age at initial presentation, were analyzed separately. In the age group 0-1 year, 71/113 (63%) patients had at least one exacerbation, and 20 experienced recurrent exacerbations (>/=3). Predisposing risk factors for exacerbation were damp housing (odds ratio (OR) 7.6 (2. 0-28.6)) and colds (OR 3.6 (1.4-9.6)), and for recurrent exacerbations sensitization to inhalant allergens (Phadiatop(R)) (OR 8.1 (1.6-40.5)) and damp housing (OR 3.8 (1.1-12.8)). Hospital admissions were significantly associated with number of exacerbations. In the age group 2-4 years, 58/144 (40%) patients had at least one exacerbation, and 21 experienced recurrent exacerbations (>/=2). Predisposing risk factors for exacerbation were mean age at initial presentation (OR 0.92 (0.88-0.97)) and level of total IgE (OR 2.3 (1.4-3.9)), whereas for recurrent exacerbations no predictor variables were found. Hospital admissions were significantly associated with damp housing. Results from this study may facilitate recognition of young asthmatic patients at risk of (recurrent) exacerbations, and help to identify those in whom early intervention with anti-inflammatory therapy may be necessary. We also emphasize the importance of preventive measures in decreasing damp housing.