Trajectories of early-onset rhinitis in the Singapore GUSTO mother-offspring cohort.

BACKGROUND: The natural history of childhood rhinitis is not well described. OBJECTIVE: This study aimed to identify different rhinitis trajectories in early childhood and their predictors and allergic associations. METHODS: Rhinitis symptoms were ascertained prospectively from birth until 6 years using standardized questionnaires in 772 participants. Rhinitis was defined as one or more episodes of sneezing, runny and/or blocked nose >2 weeks duration. Latent trajectories were identified using group-based modelling, and their predictive risk factors and allergic associations were examined. RESULTS: Three rhinitis trajectory groups were identified: 7.6% (n = 59) were termed early transient rhinitis, 8.6% (n = 66) late transient rhinitis, and 6.6% (n = 51) persistent rhinitis. The remaining 77.2% (n = 596) were classified as non-rhinitis/reference group. Early transient rhinitis subjects were more likely of Indian ethnicity, had siblings, reported childcare attendance, early wheezing and eczema in the first 3 years of life. Late transient rhinitis was associated with antenatal exposure to smoking, higher maternal education levels, and wheezing at age 36-72 months. Persistent rhinitis was associated with male gender, paternal and maternal history of atopy, eczema, and house dust mite sensitization. CONCLUSIONS & CLINICAL RELEVANCE: Risk factors for early transient rhinitis involve a combination of genetic and early environmental exposures, whereas late transient rhinitis may relate to maternal factors and early respiratory infections independent of atopy. In contrast, persistent rhinitis is strongly associated with atopic risk and likely represents the typical trajectory associated with allergic disorders. Allergic rhinitis symptoms may commence as early as the first year of life and may inform development of early interventive strategies.

Cesarean section and risk of allergies in Ecuadorian children: A cross-sectional study.

BACKGROUND: Studies have shown an association between cesarean section (CS) and increased prevalence of childhood allergic diseases. While these observations have been consistent in industrialized countries, evidence from developing countries is limited. OBJECTIVE: To assess the association between the mode of delivery and allergic diseases in children aged 3-12 years in Quito, Ecuador. METHODS: In this cross-sectional study, parents were surveyed using an anonymous, standardized questionnaire from the International Study of Asthma and Allergies in Childhood project to assess the presence of asthma, allergic rhinitis, atopic dermatitis, and food allergies in their children. The children's age, sex, birthplace, delivery mode (CS/vaginal), socioeconomic status, and ethnicity were recorded. Other parameters included gestational age, breastfeeding, smoking status during pregnancy, and parental allergic diseases. RESULTS: After adjusting for confounding factors, children delivered via CS were found to have a higher risk of wheezing (odds ratio [OR] = 4.12, 95% confidence interval [CI]: 1.43-11.89), physician-diagnosed asthma (OR = 24.06; 95% CI: 1.98-292.3), and pimples, or eczema with the itching for 6 months (OR = 2.65; 95% CI: 1.06-6.61) than children delivered vaginally. No association was found between the delivery mode and rhinitis or food allergies. After stratifying by socioeconomic status, CS was only associated with allergic disorders in children of medium/high socioeconomic backgrounds. CONCLUSIONS: As seen in industrialized settings, children born by CS in nonindustrialized countries have an increased risk of developing allergic disorders including asthma and dermatitis, compared to those delivered vaginally.

Are environmental risk factors for current wheeze in the International Study of Asthma and Allergies in Childhood (ISAAC) phase three due to reverse causation?

BACKGROUND: Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC) measured the global prevalence of symptoms of asthma in children. We undertook comprehensive analyses addressing risk factors for asthma symptoms in combination, at both the individual and the school level, to explore the potential role of reverse causation due to selective avoidance or confounding by indication. OBJECTIVE: To explore the role of reverse causation in risk factors of asthma symptoms. METHODS: We compared two sets of multilevel logistic regression analyses, using (a) individual level exposure data and (b) school level average exposure (ie prevalence), in two different age groups. In individual level analyses, reverse causation is a possible concern if individual level exposure statuses were changed as a result of asthma symptoms or diagnosis. School level analyses may suffer from ecologic confounding, but reverse causation is less of a concern because individual changes in exposure status as a result of asthma symptoms would only have a small effect on overall school exposure levels. RESULTS: There were 131 924 children aged 6-7 years (2428 schools, 25 countries) with complete exposure, outcome and confounder data. The strongest associations in individual level analyses (fully adjusted) were for current paracetamol use (odds ratio = 2.06; 95% confidence interval 1.97-2.16), early life antibiotic use (1.65; 1.58-1.73) and open fire cooking (1.44; 1.26-1.65). In school level analyses, these risk factors again showed increased risks. There were 238 586 adolescents aged 13-14 years (2072 schools, 42 countries) with complete exposure, outcome and confounder data. The strongest associations in individual level analyses (fully adjusted) were for current paracetamol use (1.80; 1.75-1.86), cooking on an open fire (1.32; 1.22-1.43) and maternal tobacco use (1.23; 1.18-1.27). In school level analyses, these risk factors again showed increased risks. CONCLUSIONS & CLINICAL RELEVANCE: These analyses strengthen the potentially causal interpretation of previously reported individual level findings, by providing evidence against reverse causation.

Neonates colonized with pathogenic bacteria in the airways have a low-grade systemic inflammation.

BACKGROUND AND OBJECTIVES: The development of childhood asthma is associated with neonatal colonization with pathogenic bacteria in hypopharynx. Furthermore, established asthma is associated with systemic low-grade inflammation. We here report on the association between neonatal colonization with pathogenic bacteria in hypopharynx and the development of systemic low-grade inflammation. METHODS: Bacterial colonization of the hypopharynx with Moraxella catharralis, Haemophilus influenzae, and/or Streptococcus pneumoniae was assessed in asymptomatic children from the Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000 ) cohort at age 1 month by culturing technique (N = 238) and by quantitative polymerase chain reaction (qPCR) technique (N = 249) and in the COPSAC2010 cohort by culturing at age 1 month (N = 622) and again at age 3 months (N = 613). Systemic low-grade inflammation was determined in both cohorts at age 6 months by measuring plasma levels of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (lL-6). RESULTS: In both cohorts, bacterial colonization was associated with increased levels of hs-CRP: COPSAC2000 , 1 month culturing (geometric mean ratio of colonized/noncolonized [95% CI]), 1.39 [0.97-2.01], P = .08; 1 month qPCR, 1.55 [1.14-2.10], P < .01; COPSAC2010 , 1 month, 1.52 [1.23-1.87], P < .01; and 3 month, 1.57 [1.30-1.90], P < .01. A multiparametric principal component analysis incorporating hs-CRP, TNF-α, and IL-6 confirmed a systemic inflammatory profile in children colonized with M. catharralis, H. influenzae. and/or S. pneumoniae in the hypopharynx compared to noncolonized children (P-values < .05). CONCLUSION: The composition of the upper airway microbiome in early life may cause systemic low-grade inflammation.