Childhood wheeze phenotypes show less than expected growth in FEV1 across adolescence.

RATIONALE: Better characterization of childhood wheeze phenotypes using newer statistical methods provides a basis for addressing the heterogeneity of childhood asthma. Outcomes of these phenotypes beyond childhood are unknown. OBJECTIVES: To determine if adolescent respiratory symptoms, lung function, and changes in lung function over adolescence differ by childhood wheeze phenotypes defined through latent class analysis. METHODS: A prospective birth cohort (Melbourne Atopy Cohort Study) followed 620 high allergy-risk children, recording respiratory symptoms and spirometry at 12 and 18 years. Regression analyses identified relationships between wheeze phenotypes (never/infrequent, early transient, early persistent, intermediate onset, and late onset) and lung function, change in lung function (12-18 yr), respiratory symptoms, and asthma. The baseline classification was never/infrequent wheeze. MEASUREMENTS AND MAIN RESULTS: Deficits in expected growth of lung function, measured by change in prebronchodilator FEV1 between 12 and 18 years, were found for early persistent (reduced 290 ml; 95% confidence interval [CI], 82-498), intermediate-onset (reduced 210 ml; 95% CI, 62-359), and late-onset wheeze (reduced 255 ml; 95% CI, 69-442). Intermediate-onset wheezers had persistent FEV1 deficit after bronchodilator at 18 years (reduced 198 ml; 46,350). Current asthma risk was increased for all phenotypes except early transient, which was also not associated with lung function deficits at 12 or 18 years. CONCLUSIONS: Persistent wheeze phenotypes in childhood were associated with reduced growth in prebronchodilator FEV1 over adolescence. Intermediate-onset wheezers showed irreversible airflow limitation by 18 years. Conversely, early transient wheeze was a benign condition with no sequelae for respiratory health by age 18.

Perinatal cat and dog exposure and the risk of asthma and allergy in the urban environment: a systematic review of longitudinal studies.

BACKGROUND: The literature is contradictory concerning pet exposure and the risk of development of asthma and other allergic diseases. Using longitudinal studies, we aimed to systematically review the impact of pet ownership in the critical perinatal period as a risk factor for allergies in childhood. METHODS: Medline database was searched for urban cohort studies with perinatal exposure to cats and/or dogs and subsequent asthma or allergic disease. RESULTS: Nine articles, comprising 6498 participants, met inclusion criteria. Six found a reduction in allergic disease associated with perinatal exposure to dogs or, cats or dogs. One study found no association. Two found increased risk only in high-risk groups. CONCLUSION: Longitudinal studies in urban populations suggest that perinatal pets, especially dogs, may reduce the development of allergic disease in those without a family history of allergy. Other unmeasured factors such as pet-keeping choices in allergic families may be confounding the association seen in these high-risk families, and further study is required.

Early childhood infections and immunisation and the development of allergic disease in particular asthma in a high-risk cohort: A prospective study of allergy-prone children from birth to six years.

The role of early childhood infections and immunisation in the development of allergic diseases remains controversial. To examine these associations, six hundred and twenty infants with first-degree relatives with allergic diseases were recruited into the Melbourne Atopy Cohort Study. Information on risk factors and outcomes was collected by interviewer administered questionnaire and was based on parental report and/or a physician's diagnosis. Risk factors examined included early childhood infections (including gastroenteritis, otitis media and lower respiratory tract infections) and immunisations in the first 2 yr of life. Outcomes were current asthma, allergic rhinitis and eczema at 6 yr of age. Univariate and multivariate regression analysis were used to estimate relative risk (RR) and assess confounding. By 6 yr, 79% of the original cohort remained in the study. Those with at least three episodes of gastroenteritis showed an increased risk (crude RR 2.36, 95%CI 1.41 3.95; adjusted RR 2.03 95%CI 1.50 2.75) for the later development of asthma at age 6. Of the scheduled immunisations, Sabin immunisation in the second year had a reduced risk of asthma at 6 yr (crude RR 0.60, 95%CI 0.37 0.98; adjusted RR 0.63 95%CI 0.39 1.02). Combined diphtheria and tetanus (CDT) immunisation in the first year had an increased risk of asthma at 6 yr (RR 1.76, 95%CI 1.11 2.78; adjusted RR 1.88 95%CI 1.28 2.77). Recurrent gastroenteritis in early childhood is associated with a later risk of asthma. This may reflect a cause and effect relationship, or exposure to common risk factors. In contrast, Sabin immunisation in the second year is associated with a decreased risk of asthma in later childhood. CDT immunisation in the first year may be a risk factor for asthma, but the need for CDT immunisation may also be a marker of increased risk of asthma in later childhood.

Soy consumption is not a risk factor for peanut sensitization.

BACKGROUND: A recent cohort study suggested that intake of soy milk or soy formula was associated with peanut allergy. If this finding is confirmed, it suggests an avenue for modification of diet as a peanut allergy prevention strategy. OBJECTIVE: To investigate the relationship between soy consumption and peanut sensitization in a prospective cohort study of children. METHODS: A total of 620 babies with a family history of allergic disease were recruited. Dietary information was obtained from telephone interviews every 4 weeks from birth until 15 months and then again at 18 months and 2 years. Skin prick tests to peanut, milk, and egg were performed at 6, 12, and 24 months. A wheal size > or = 3 mm was considered positive for sensitization. RESULTS: Children whose parents elected to introduce soy formula or soy milk into their children's diet were more likely to be sensitized to peanuts at 2 years (odds ratio, 2.02; 95% CI, 1.04-3.92; P = .039). However, this relationship was explained by feeding of soy to children who had siblings with milk allergy or were themselves sensitized to milk. After adjusting for these factors, there was no evidence of an association between soy consumption and peanut sensitization (odds ratio, 1.34; 95% CI, 0.64-2.79; P = .434). CONCLUSION: The association between soy consumption and peanut sensitization is not causal but merely a result of preferential use of soy milk in infants with a personal or family history of cow's milk allergy. Future studies should take the confounding effects related to dietary modifications by parents into account when investigating the association between diet and childhood allergic diseases.

IgE food sensitization in infants with eczema attending a dermatology department.

OBJECTIVES: Because community-based studies, which report IgE food sensitization (IgE-FS) in more than 80% of infants with moderate atopic eczema, may be influenced by referral bias, we assessed the prevalence of IgE-FS in a cohort of infants with moderate atopic eczema attending a dermatology department clinic. STUDY DESIGN: Consecutive infants (n = 51, 39 males; median age, 34 weeks; range, 20 to 51 weeks) with moderate atopic eczema referred to a university-affiliated dermatology department were studied prospectively. Clinical history and eczema severity were documented. IgE-FS was assessed by the skin prick test (SPT; n = 51) and food-specific serum IgE antibodies (CAP-FEIA test; n = 41). IgE-FS was diagnosed if the SPT or CAP-FEIA level exceeded the >95% predictive reference cutoff for positive food challenges. RESULTS: Based on SPT, 44 of 51 infants (86%; 95% confidence interval [CI] = 74% to 94%) had IgE-FS (cow's milk, 16%; egg, 73%; peanut, 51%). Using age-specific 95%-predictive cutoff values, CAP-FEIA identified 34 of 41 infants (83%; 95% CI = 68% to 93%) with IgE-FS (cow's milk, 23%; egg, 80%). Forty-six (90%) infants had IgE-FS to at least 1 food item by either SPT or CAP-FEIA. CONCLUSIONS: Atopic eczema was found to be closely associated with IgE-FS in infants attending a dermatology department.