Exhaled Nitric Oxide in Wheezy Infants Predicts Persistent Atopic Asthma and Exacerbations at School Age

Risk factors for recurrent wheezing after bronchiolitis

BACKGROUND

This study aimed to determine whether there was an association between certain factors in patients with bronchiolitis and recurrent wheezing in childhood.

METHOD

In 2021 we tracked children hospitalized for bronchiolitis at Chengdu Women's and Children's Central Hospital in 2017. The patients were classified into recurrent wheezing group (RWG) and non-recurrent wheezing group (NRWG). Possible risk factors including maternal age, school-age siblings, allergic history, atopic dermatitis, allergic rhinitis, atopic family history, severity of the condition, duration of hospitalization, nasopharyngeal secretions culture, blood eosinophil counts, FeNO and skin prick test were compared between the two groups. Continuous variables were analyzed by independent sample t-test for normal distribution and Mann-Whitney U-test for non-normal distribution. Categorical variables were tested using chi-square tests. Multifactor analysis was conducted by stepwise logistics regression analysis.

RESULTS

In total 167 participants were included, of which 26 and 141 were in RWG and NRWG respectively. In RWG children represented higher maternal age (P = 0.02) and greater probability of allergic history, atopic dermatitis, allergic rhinitis, atopic family history (odds ratio [OR] = 4.0,3.7, 7.8, 10.9 respectively, P < 0.01). However, school-age siblings, severity of the condition, duration of hospitalization, blood eosinophil counts, fractional exhaled nitric oxide and skin prick test results seemed unrelated to recurrent wheezing. In the subgroup analysis of nasopharyngeal secretion culture, there were more Moraxella catarrhalis-positive in RWG(P = 0.043). Atopic dermatitis, allergic rhinitis and atopic family history were identified as independent risk factors for recurrent wheezing.

CONCLUSION

Some children with bronchiolitis will develop recurrent wheezing, and the risk factors are allergic history, Moraxella catarrhalis infection or colonization, atopic dermatitis, allergic rhinitis and atopic family history; the latter three are independent risk factors.

Lung function, allergic sensitization and asthma in school-aged children after viral-coinfection bronchiolitis

Our main objective was to compare the lung function, the rate of allergic sensitization and the prevalence of asthma at 7–9 years in children hospitalized for bronchiolitis with viral coinfection versus single viral infection. Observational study in children with previous bronchiolitis and current age 7–9 years. Clinical data were collected. Fraction of exhaled nitric oxide (FeNO) determination, spirometry and skin prick test for common aeroallergens were performed. A total of 181 children hospitalized for bronchiolitis (40 coinfections and 141 single infections), with median age of 8.3 years (IQR:7.5–9.1) were included. Single-HRV-infections showed lower basal FEV1(%) than coinfections (p = 0.04) and lower z-score FEV1 than single-RSV-infections (p = 0.04) or coinfections (p = 0.02). Also, single-HRV-infections had lower post-bronchodilator FEV1(%) and z-score FEV1 values than coinfections (p = 0.03 and p = 0.03). Single-HRV-bronchiolitis was an independent risk factor for FEV1 < 80% (p = 0.007). FeNO value > 25 ppb was detected in 21(12.5%) cases, without differences between viral groups (p = 0.768). The prevalence of allergic sensitization was similar in coinfections (31.4%) versus single infections (38.7%), (p = 0.428). The highest frequency of allergic rhinitis was observed in single-HRV patients (p = 0.004). The respiratory morbidity at 7–9 years of coinfected patients was similar to the single-HRV ones. In contrast, the likelihood of current asthma was up to 5 times higher in RSV/HRV coinfections than in the single-RSV-infections ones (p = 0.012). The respiratory morbidity at 7–9 years of age after severe bronchiolitis is significantly higher in single-HRV or viral coinfection patients that in single-RSV ones. Single-HRV-bronchiolitis is independently associated with lower lung function at school-age.

Atypical asthma in children who present with isolated chest tightness: risk factors and clinical features

OBJECTIVE

Asthmatic children presenting with chest tightness as the only symptom have not been widely recognized. This study attempted to find risk factors, summarize clinical features and offer some suggestions for the diagnosis of this atypical asthma.Methods: We studied 94 children, aged 6 to 14 years, who complained only of chest tightness. Data from clinical manifestations and laboratory tests were analyzed. The atypical asthma group (n = 58) showed positive bronchial challenge tests, and symptoms either improved or resolved in response to the bronchodilator. The control group (n = 36) had negative results on the bronchial challenge, diurnal PEF, and BDR tests, and no response to asthma treatment with bronchodilator.Results: Pollution, weather, recent house renovation, and air-conditioning use may be risk factors for children with atypical asthma. These children had more accompanying symptoms of rhinitis and rhinitis family history (P < 0.05), and a higher positive detection rate of inhaled allergens and multiple sensitizations. Parameters of the pulmonary function test were lower in the atypical asthma group than in the control group, and they also had higher FeNO values. If a cutoff value of improvement in FEV1 of BDR were set at 8.9%, sensitivity would be 48.2%, which is higher than a 12% cutoff.Conclusions: Environmental factors appeared to cause development of the isolated chest tightness symptom. Clinical history and laboratory tests could provide partial values for this diagnosis. In the absence of a bronchial challenge test, a margin of improvement in FEV1 of BDR set at 8.9% may be helpful.

Exhaled nitric oxide in premature and mature infants during the first months of life

AIM

In this review, we aim to describe how exhaled Nitric Oxide(NO) changes during the first months of life in premature and mature infants.

METHOD

Review of the literature up to August 2020, on online, tidal breathing NO measurements in unsedated infants. The association between Fractional exhaled NO(FeNO) values, postnatal age, and prematurity was analysed using linear mixed modeling and Spearman's rank correlation.

RESULTS

Median FeNO during the first months of life was 5.9 and 8.5 ppb in premature and mature infants, respectively. The linear mixed model analysis showed a significant effect of postnatal age on FeNO (p = 0.007).

CONCLUSION

Our study suggests that FeNO is higher in mature infants than premature infants, and FeNO increased with postnatal age at approximately the same pace in both groups.

Application of exhaled nitric oxide (FeNO) in pediatric asthma

PURPOSE OF REVIEW

Fractional concentration of Nitric Oxide in the exhaled air (FeNO) is a moderately good biomarker of type-2 airway inflammation, and its measurement is feasible also in children. The available evidence is still not enough to support the routine use of FeNO to diagnose or manage asthma in every patient in clinical practice. However, its role in identifying asthma with eosinophilic inflammation is of particular interest in the management of severe asthma.

RECENT FINDINGS

In healthy subjects, FeNO levels increase with age and height, particularly in males, and are also influenced by ethnicity. FeNO measurement can support asthma diagnosis and help in predicting asthma development later in life in young children with recurrent wheezing. FeNO-guided asthma management is effective in reducing asthma exacerbations but may result in a higher daily dose of inhaled corticosteroids. FeNO can also be used as a marker to evaluate adherence to asthma treatment and predict response to different biologicals, especially Omalizumab and Dupilumab.

SUMMARY

This review outlines recent data on the application of FeNO in childhood-onset asthma diagnosis and management, as well as in phenotyping subjects with severe asthma who may benefit from monoclonal antibodies administration.

Preschool Wheezing and Gastro-Esophageal Reflux: --Causal or Casual Coincidence? Update from Literature

Gastroesophageal reflux (GER) and wheeze are two common conditions in children. GER has been advocated as a causative factor for explaining recurrent to persistent respiratory symptoms at any age. This association very often means that many children with cough, wheezing, or recurrent respiratory infections receive empirical anti-reflux medications. The causal relationship is still largely discussed. Compared to the large number of studies in infants and adolescents, literature on the relationship between GER and wheeze in preschool children is scarce and inconclusive. The aim of the present narrative review was to summarize what is known so far, and what the literature has proposed in the last 20 years, on the relationship between preschool wheezing and GER. In preschool children with respiratory symptoms there is a high rate of positivity of reflux testing, for this reason pH-MII testing and endoscopy are recommended. Flexible bronchoscopy may be useful to exclude anatomical abnormalities as the cause of wheezing in infancy and preschool years. Several biomarkers, as well as empirical anti-reflux therapy, have been proposed for the diagnosis of GER-related airway diseases, but the conclusions of these studies are controversial or even conflicting. There is a great need for future clinical trials to confirm or rule out the association.