An increased number of acute respiratory infections (ARIs) before age 2 may increase the risk for asthma at age 7, according to a study published in The Journal of Allergy and Clinical Immunology.
Researchers tracked children’s health from birth and analyzed their medical records and ARI diagnoses before age 2 as part of the STEPS observational prospective birth cohort study.
Children with asthma at age 7 spent more days with ARI symptoms, had more lower respiratory tract infections and doctor visits, and spent more time on antibiotics for ARIs before age 2 compared with children who did not develop asthma. They were also more frequently hospitalized for ARIs before age 2. The median duration of ARIs before age 2 was longer in children who developed asthma at age 7 years compared with those who did not (8.0 [IQR, 5.0-12.0] vs 7.0 [IQR, 4.0-12.0] days; P =.04).
ARIs in children who developed asthma at age 7 were more severe (with the same the virus etiology) compared with children who did not develop asthma at age 7. Children who had ≥9 ARIs per year before age 2 had a higher risk for asthma at age 7 compared with children who had <5 ARIs per year in the same timeframe (adjusted odds ratio, 7.20; 95% CI, 2.49-20.88).
The researchers concluded that “findings suggest common mechanisms behind susceptibility to ARIs and asthma. Airway hyperreactivity in children who later develop asthma may contribute to prolonging symptoms during ARIs.”
Toivonen L, Forsström V, Waris M, Peltola V. Acute respiratory infections in early childhood and risk of asthma at 7 years of age [published online September 5, 2018]. J Allergy Clin Immunol. doi:10.1016/j.jaci.2018.08.025