METHODS: This is a retrospective case-control study (2010-2013) of pediatric asthma patients (1-21years) treated in a university based pediatric asthma clinic. OSA was diagnosed in 48 out of 78 patients who were referred for a sleep study with apnea hypopnea index (AHI) >1.5. Specific IgE for aeroallergen sensitization (ImmunoCAP®) was measured. Data were analyzed using t-tests and Chi-square tests.
RESULTS: 75% of children had a positive ImmunoCAP® test indicating sensitivity to allergens in our cohort. Patients with positive ImmunoCAP® tests had significantly higher hypopnea index (p=0.03) but not AHI. There were no significant differences in allergen sensitization, total IgE, absolute eosinophil count, eosinophil percentage, asthma severity or BMI in OSA group compared to non-OSA group. The most common sensitized allergens were dust mite and cockroaches in the OSA group and dust mite and mouse in non-OSA patients. There was higher prevalence in perennial allergen sensitization (dust mites and animal dander) in the non-OSA group compared to OSA group (60.7% vs 35.4% respectively, P=0.15).
CONCLUSIONS: Allergen sensitization complicates sleep disordered breathing with hypopneas but is not a significant risk factor for OSA in our cohort. A higher prevalence in perennial allergen sensitization was noted in non-OSA patients.