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.

Purpose Macrolide-resistant Mycoplasma pneumoniae pneumonia (MPP) is characterized by prolonged fever and radiological progression despite macrolide treatment. Few studies have examined serum procalcitonin (PCT) level in children with MPP. We aimed to investigate the association of acute inflammation markers including PCT with clinical parameters in children with MPP. Methods A total of 147 children were recruited. The diagnosis of MPP relied on serial measurement of IgM antibody against mycoplasma and/or polymerase chain reaction. We evaluated the relationships between C-reactive protein (CRP), PCT, and lactate dehydrogenase (LDH) levels and white blood cell (WBC) counts, and clinical severity of the disease. We used multivariate logistic regression analysis to estimate the odds ratio for prolonged fever (>3 days after admission) and hospital stay (> 6 days), comparing quintiles 2–5 of the PCT levels with the lowest quintile. Results The serum PCT and CRP levels were higher in children with fever and hospital stay than in those with fever lasting ≤ 3 days after admission and hospital stay ≤ 6 days. CRP level was higher in segmental/lobar pneumonia than in bronchopneumonia. The LDH level and WBC counts were higher in children with fever lasting for >3 days before compared to those with fever lasting for ≤ 3 days. The highest quintile of PCT levels was associated with a significantly higher risk of prolonged fever and/or hospital stay than the lowest quintile. Conclusion Serum PCT and CRP levels on admission day were associated with persistent fever and longer hospitalization in children with MPP.

Methods:We recruited 59 children with only rhinitis and 33 controls without any allergic diseases. Serum IL-31 and 25(OH) D levels were assayed using an enzyme-linked immunosorbent assay and high-performance liquid chromatography, respectively. The patients were considered to have atopic sensitization if the levels of serum specific IgE to inhalant allergens as assessed using immunoCAP were ≥ 0.35 IU/mL or if they tested positive for one or more allergens by the skin prick test. Results: Of children with rhinitis, 25 had nonatopy (NAR), and 34 children had atopy (AR). Serum 25(OH) D levels were significantly lower in the rhinitis group than in the control group, while there was no significant difference serum 25(OH) D levels between the AR and NAR groups. Children with rhinitis demonstrated higher serum IL-31 levels than controls; however, there was no difference in serum IL-31 levels between the AR and NAR groups. Serum 25(OH) D levels were inversely correlated with serum IL-31 levels and blood eosinophil counts. On the other hand, serum 25(OH) D levels were not correlated with total serum IgE levels. Conclusion: Serum 25(OH) D and IL-31 may play a role in the pathogenesis of rhinitis via mechanisms other than IgE-related pathway. (Allergy Asthma Respir Dis 2018;6:41-46)