Recurrent wheeze and its relationship with lung function and airway inflammation in preschool children: a cross-sectional study in South Korea

Abstract

BackgroundRelationship between recurrent wheeze and airway function and inflammation in preschool children is not fully known.ObjectiveTo investigate the relationship between recurrent wheeze and airway inflammation, lung function, airway hyper-reactivity (AHR) and atopy in preschool children.DesignObservational study, comparing forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and mid-forced expiratory flow (FEF25%–75%), dose–response slope (DRS), exhaled nitric oxide (eNO) and atopic sensitisation between children with recurrent wheeze and those without.SettingPopulation-based, cross-sectional study in Seoul and the Gyeonggi province of Korea conducted as a government-funded programme to perform standardised measurement of the prevalence of allergic diseases, and related factors, in preschool children.Participants900 children aged 4–6 years.Primary and secondary outcome measureseNO, FEV1/FVC, FEF25%–75%, DRS, atopic sensitisation and allergic diseases.MethodsChildren completed the modified International Study of Asthma and Allergies in Childhood questionnaire and underwent eNO assessments, spirometry, methacholine bronchial provocation tests and skin prick tests. Recurrent wheeze was defined as having a lifetime wheeze of more than three episodes, based on the questionnaire. The frequency of hospitalisation and emergency room visits was also obtained by means of the questionnaire. ‘Current’ wheeze was defined as having symptoms or treatments within the past 12 months.ResultsThe prevalence of recurrent wheeze was 13.4%. Children with recurrent wheeze showed a higher prevalence of lifetime or current allergic rhinitis (p=0.01 and p=0.002, respectively) and lifetime atopic dermatitis (p=0.007). Children with recurrent wheeze showed lower FEV1/FVC (p=0.033) and FEF25%–75% (p=0.004), and higher eNO levels (p=0.013) than those without recurrent wheeze. However, the DRS, prevalence of atopic sensitisation and serum IgE levels were not significantly different between the two groups.ConclusionsRecurrent wheeze in preschool children may be associated with airway inflammation and diminished airway function, but not with AHR or atopy.

Asthma predictive index as a useful diagnostic tool in preschool children: a cross-sectional study in Korea

“…All tests were performed by the same welltrained technicians to ensure standardization of the results. 8) Outcome variables were the prevalence of allergic diseases, hospitalization or Emergency Department (ED) visit, atopic sensitization, blood eosinophil counts, serum IgE levels, forced expiratory volume in 1 second (FEV1), bronchodilator response ver ted to logarithmic values for analysis.…”

“…FeNO was measured using a Niox Mino device (Aerocrine, Solna, Sweden) as described in a previous study. 6,8) The mean value of the 3 measurements was recorded as the final FeNO.…”

“…A skin prick test (Allergopharma, Reinbek, Germany) using 16 common allergens (12 aeroallergens and 4 food allergens) was performed as previously mentioned. 8) The test was considered positive when the mean wheal size in response to an allergen was greater than 3 mm and at least equal to or greater than the mean wheal size in response to histamine. Atopic sensitization was defined as a positive skin prick test for any allergen.…”

Patterns of health care use related to respiratory conditions in early life: A birth cohort study with linked administrative data

“…One in two children experiences at least one wheezing episode in early childhood . Recurrent wheezing in early life may lead to reduced lung function in preschoolers . Some children will subsequently be diagnosed with a chronic respiratory condition, such as asthma, the most common chronic disease of childhood globally .…”

“…1 Recurrent wheezing in early life may lead to reduced lung function in preschoolers. 2,3 Some children will subsequently be diagnosed with a chronic respiratory condition, such as asthma, the most common chronic disease of childhood globally. 4 The associated health care burden is huge; respiratory conditions constitute nearly half of primary care visits 5 and over 40% of hospitalizations in children.…”