Influence of host and environmental factors on wheezing severity in infants: findings from the PARIS birth cohort.

BACKGROUND: Determinants of wheezing severity are poorly documented in infants. OBJECTIVES: To study the determinants of wheezing severity in infants aged 18 months followed-up in the PARIS (« Pollution and Asthma Risk : an Infant Study ¼) birth cohort. METHODS: Data on wheezing disorders, medical visits and medications, as well as biological markers of atopy, were collected during a medical examination at age 18 months. Severe wheeze was defined as wheeze that required inhaled corticosteroid and/or hospital-based care. Environmental exposures were assessed prospectively with regular questionnaires. Risk factors for wheeze in the first 18 months of life were assessed by multivariate regression models. RESULTS: Participation in the medical examination concerned 48.2% of the original cohort. Prevalence of wheeze was 560/1879 (35.7%) and was influenced by male gender, parental history of asthma, siblings, daycare attendance, heavy parental smoking at home, and carpet covered floor in the child's bedroom. Being overweight increased the risk of wheeze by 62% (OR = 1.62, 95%CI 1.13-2.32). In addition, trends towards an increased risk of wheeze were found in infants exposed to daily use of cleaning sprays and to renovation activities. Conversely, the presence of a cat reduced the risk of wheeze (OR = 0.65, 95%CI 0.47-0.89), without any evidence of healthy-pet keeping effect. Severe wheeze concerned 286 of the wheezers (42.7%). The prevalence of severe wheeze was related to atopy, and risk of severe wheeze was in particular increased in infants having eosinophilia (OR = 1.76, 95%CI 1.21-2.55) or being sensitized to ≥ 2 allergens (OR = 1.88, 95%CI 1.13-3.14). CONCLUSIONS AND CLINICAL RELEVANCE: Whilst risk factors for wheeze before 18 months of age are factors related to infections, indoor air pollution, and being overweight, the severity of wheeze is mainly due to the atopic status of the child. We suggest that atopy should be further considered in the assessment of wheezing severity in infants.

[Management of wheezing disorders in infants participating in the PARIS birth cohort]. / Prise en charge des sifflements chez le nourrisson dans la cohorte de nouveau-nés PARIS.

BACKGROUND: While wheezing disorders are common in preschool children, their management is not well defined. The aim of this study was to assess the use of medical health care resources due to wheezing disorders in infants aged 18 months followed up in the Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. METHODS: Data on wheezing disorders, medical visits and medication on account of respiratory disorders during the previous 12 months were collected with a standardized questionnaire, administered by a paediatrician, during the health check offered to every child aged 18 months included in the PARIS birth cohort. RESULTS: The prevalence of wheezing disorders during the past 12 months amounted to 560/1974 (28.4%). Among wheezers, 493 (89.3%) required a medical visit because of difficult breathing; 61 (11.0%) went to the emergency room, 35 (6.4%) were admitted to the hospital and 375 (67.2%) received an inhaled anti-asthmatic medication. Recourse to chest physiotherapy was reported in 472 of them (85.1%). CONCLUSION: This study confirms the high use of healthcare resources because of wheezing disorders in infants and suggests a higher use of anti-asthmatic medications in France compared to other European countries.

Does allergic rhinitis exist in infancy? Findings from the PARIS birth cohort.

BACKGROUND: Early onset of allergic rhinitis (AR) is poorly described, and rhinitis symptoms are often attributed to infections. This study analyses the relations between AR-like symptoms and atopy in infancy in the PARIS (Pollution and Asthma Risk: an Infant Study) birth cohort. METHODS: Data on AR-like symptoms (runny nose, blocked nose, sneezing apart from a cold) were collected using a standardized questionnaire administered during the health examination at age 18 months included in the follow-up of the PARIS birth cohort. Parental history of allergy and children's atopy blood markers (blood eosinophilia ≥470 eosinophils/mm(3) , total immunoglobulin E ≥45 U/ml and presence of allergen-specific IgE) were assessed. Associations were studied using multivariate logistic regression models adjusted for potential confounders. RESULTS: Prevalence of AR-like symptoms in the past year was 9.1% of the 1850 toddlers of the study cohort. AR-like symptoms and dry cough apart from a cold were frequent comorbid conditions. Parental history of AR in both parents increased the risk of suffering from AR-like symptoms with an OR 2.09 (P=0.036). Significant associations were found with the presence of concurrent biological markers of atopy, especially blood eosinophilia and sensitization to house dust mite (OR 1.54, P=0.046 and OR 2.91, P=0.042) whereas there was no relation with sensitization to food. CONCLUSIONS: These results support the hypothesis that AR could begin as early as 18 months of life. Suspicion of AR should be reinforced in infants with parental history of AR or biological evidence of atopy, particularly blood eosinophilia and sensitization to inhalant allergens.