Background: There is limited data for predicting the risk of exacerbations following the cessation of inhaled corticosteroids (ICS) in well controlled childhood asthma. In current study, clinical, functional and inflammatory parameters at the time of ICS withdrawal were investigated in that respect.
Methods: Forty children asymptomatic for at least 3 months on low dose ICS's were enrolled and ICS were discontinued in summer. At enrolment symptom/medication diary, pulmonary function parameters, methacholine provocation testing, peripheral blood eosinophilia, serum total and allergen-specific IgE levels and skin prick testing were performed. In a subgroup of patients, phytohemaglutinin induced secretion of IL-5, IL-13, IFN-γ and IL-10 from blood mononuclear cells were measured. Patients were assessed with symptom/medication diary and pulmonary function test every 2 months for 6 months.
Results: Eighteen of 37 patients experienced recurrence of acute asthma symptoms. In patients with acute attack (group I), changes in rhinitis symptom scores at 2nd month vs. baseline were statistically higher. In addition, group I had significantly higher rhinitis symptom scores compared to group II at fourth-month visit. Patients with acute exacerbation revealed a significant decrease in FEV1% at 2nd month compared to baseline. Moreover, group I showed significantly lower FEF 25-75% compared to group II at 2nd month. Baseline bronchial hyper-responsiveness with methacholine was found to be an independent risk factor for asthma exacerbation.
Conclusions: The findings of this study identified baseline bronchial hyperreactivity, higher rhinitis symptom scores and gradual decrease in pulmonary function parameters during follow-up as risk factors for subsequent exacerbation of asthma.