Viral etiology and atopic characteristics in high-risk asthmatic children hospitalized for lower respiratory tract infection

BACKGROUND: Viral etiology and atopic characteristics, e.g., allergens and fractional exhaled nitric oxide (FeNO), play essential roles in asthma development. This study aimed to investigate associations among them in children at high risk of developing asthma to guide reliable diagnosis and treatment of wheezing. METHODS: From April 2016 to August 2017, 135 children aged <3 years identified as being at high risk of asthma and hospitalized for lower respiratory tract infection (LRTI) with wheezing were recruited as research subjects (observation group). Real-time fluorescent polymerase chain reaction (PCR) was used to explore their etiology. Samples were also evaluated with Phadiatop (Pharmacia Diagnostics AB, Uppsala, Sweden). Additionally, 200 non-asthmatic, non-allergic, healthy children who were screened and followed up in the Echocardiography clinic during the study period were recruited as a healthy control group for FeNO measurement, and the observation group also underwent FeNO measurement. RESULTS: Among the observation group, viruses were positively detected in 49.63%. The most often detected virus was human rhinovirus (HRV; 25.19%). Compared with children aged <12 months, those aged 1–3 years were more susceptible to HRV infection and had lower sensitivity rates for inhalant allergens and higher T-IgE. The virus-detected group had a higher sensitivity rate for inhalant allergens compared with the virus-undetected group. FeNO in the observation group was lower than that in the healthy control group. The second-wheezing group had higher sensitivity rates for dust mites and fungi and higher T-IgE levels compared with the first-wheezing group. CONCLUSIONS: HRV was the most common viral pathogen present during an asthmatic attack in infants and young children at elevated risk of asthma. Allergy is a risk factor for both initial wheezing and repeated wheezing. Inhalant allergen-sensitive children are more susceptible than others to viral infection.