Airway infections in infancy and the presence of allergy and asthma in school age children

Aim: To investigate the association between a history of otitis media and respiratory tract infections in infancy and allergic sensitisation and asthma in school age children of atopic and non-atopic parents. Methods: Based on a survey of 4585 schoolchildren, three groups of children aged 6–16 years were selected, of whom 502 were eligible with complete data: (1) diagnosed asthma (n = 166); (2) wheeze within past 12 months (n = 155); and (3) no asthma/no wheeze (n = 181). This study population was further analyzed by subgroups of children with or without parental atopy. Main outcome measures were allergic sensitisation verified by skin prick test and asthma. Results: Children of atopic parents had a reduced risk of developing allergic sensitisation in school age if they had a combined history of both otitis media and lower respiratory tract infections during infancy (adjusted odds ratio (aOR) 0.13, 95% CI 0.03 to 0.50) or a history of otitis media (aOR 0.31, 95% CI 0.12 to 0.83). A history of lower respiratory tract infections in infancy increased the risk of asthma in children of non-atopic parents (aOR 4.21, 95% CI 1.68 to 10.57). Conclusion: In the present study population, a history of otitis media in infancy seems to be negatively associated with allergic sensitisation in school age children of atopic parents, whereas a history of lower respiratory tract infections was positively associated with asthma in children of non-atopic parents.     

Baby swimming and respiratory health

AIM: To estimate the effect of baby swimming in the first 6 months of life on respiratory diseases from 6 to 18 months. METHODS: We used data from The Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health in children born between 1999 and 2005 followed from birth to the age of 18 months (n = 30,870). Health outcomes: lower respiratory tract infections (LRTI), wheeze and otitis media between 6 and 18 months of age. Exposure: baby swimming at the age of 6 months. The effect of baby swimming was estimated by logistic regression analysis adjusting for potential confounders. RESULTS: About 25% of the children participated in baby swimming. The prevalence of LRTI was 13.3%, wheeze 40.0% and otitis media 30.4%. Children who were baby swimming were not more likely to have LRTI, to wheeze or to have otitis media. However, children with atopic mothers who attended baby swimming had an increased risk of wheeze, adjusted odds ratios (aOR) 1.24 (95% CI 1.11, 1.39), but not LRTI or otitis media. This was also the case for children without respiratory diseases before 6 months aOR 1.08 (95%CI 1.02-1.15). CONCLUSION: Baby swimming may be related to later wheeze. However, these findings warrant further investigation.     

Baby swimming increases the risk of recurrent respiratory tract infections and otitis media

Aim: To estimate the association between baby swimming and recurrent respiratory tract infections and otitis media in the first year of life in children of parents without and with atopy. Methods: Norwegian schoolchildren (n = 2862) was enrolled in a cross-sectional study of asthma and allergy using the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC). The outcomes were parental retrospective report of recurrent respiratory tract infections and otitis media diagnosed by a physician in the first year of life. The exposure was baby swimming during the same period. Parental atopy reflects a history of maternal or paternal asthma, hayfever or eczema. Results: The prevalence of recurrent respiratory tract infections was higher (12.3%) among children who took part in baby swimming than among those who did not (7.5%). The prevalence of recurrent respiratory tract infections during the first year of life was 5.6% and 10.5%, respectively, in children of parents without and with atopy, whereas the prevalence of baby swimming was 5.6% and 5.1%, respectively, in the two groups. Stratified analysis using parental atopy as strata showed that the increased risk of recurrent respiratory tract infections was only present among children of parents with atopy [adjusted odds ratio (aOR) 2.08, 95% confidence interval (95% CI) 1.08-4.03]. A similar trend was present for otitis media (aOR 1.77, 95% CI 0.96-3.25).

Conclusion: The results of this study suggest that baby swimming and infant respiratory health may be linked. The findings need to be examined in a longitudinal study.     

Wheeze in children: the impact of parental education on atopic and non‐atopic symptoms

de Meer G, Reijneveld SA, Brunekreef B. Wheeze in children: the impact of parental education on atopic and non‐atopic symptoms.
Pediatr Allergy Immunol 2010: 21: 823–830.
© 2009 John Wiley & Sons A/S There is conflicting evidence for the relationship between parental socioeconomic position and their children’s asthma. The aim of this study was to investigate relationships between parental education and respiratory symptoms in their children, distinguishing atopic and non‐atopic symptoms. A cross‐sectional survey among 3262 elementary school children (age 8–13) was performed; data on parental education were obtained for 3213 children. Parents completed a questionnaire on their child’s allergic and respiratory symptoms, and potential explanatory variables including family history, indoor environment, and the child’s medical history. Subsets of children were tested for atopy (n = 1983), lung function (n = 2325), and airway hyperresponsiveness (AHR) (n = 880). Logistic regression was used to assess relationships of health outcomes with parental education. A high parental education was associated with an increased risk of atopic sensitization to indoor allergens (OR 1.31, 95% CI 1.02; 1.69). Studied explanatory variables did not influence the relationship. In contrast, a high parental education protected children from wheeze (OR 0.77, 95% CI 0.61; 0.97). This only applied to non‐atopic wheeze (OR 0.65, 95% CI 0.43; 0.99) and not to atopic wheeze (OR 0.89, 95% CI 0.60; 1.31). The protection from non‐atopic wheeze in children of highly educated parents declined after adjustment for household smoking and breastfeeding (OR 0.96, 95% CI 0.58; 1.57). Similar results were observed for non‐atopic and atopic rhinitis. We conclude that children from highly educated parents are protected from non‐atopic respiratory symptoms, which is largely explained by a lower rate of household smoking and a higher rate of breastfeeding.     

Effects of early intake of fruit or vegetables in relation to later asthma and allergic sensitization in school-age children

AIM: To assess the associations between nutrition supplements in infancy and later asthma and allergy in school-age children, and to explore the impact of environmental factors in early life. METHODS: Five hundred and two children underwent clinical examination, skin prick test and a second parentally completed questionnaire within 2 y of a cross-sectional questionnairebased study, including 4585 primary school children (6-16 y old) in 1994 from urban Oslo (37%), the mountainous area of Hallingdal (42%), and the industrial, coastal area of Odda (21%). The children were selected from the 1994 survey on the basis of reported diagnosed asthma (n=166), wheeze in the last 12 mo (n=155) and no asthma/no wheeze (n=181). Questions were related to nutrition and environmental exposure in early life. Possible associations between allergic sensitization or asthma at school age and exposures were estimated by logistic regression analysis, adjusting for potential confounders. RESULTS: Daily intake of fresh fruit or vegetables, but not extra vitamins or cod liver oil supplements, in infancy decreased the risk of asthma (adjusted odds ratio (aOR) 0.57 (95% confidence interval (CI): 0.37-0.88). Early supplements of cod liver oil and extra vitamins were associated with increased allergic sensitization (aOR 1.78 (95% CI: 1.03-3.07) and 1.71 (95% CI: 1.01-2.88), respectively). A significantly higher prevalence of allergic sensitization was found in children living in Hallingdal compared to Odda, while the latter children, on the other hand, had the highest prevalence of house dust mite allergy (p = 0.001 vs Hallingdal and p = 0.04 vs Oslo). CONCLUSION: The present study suggests that the early introduction of daily fresh fruit or vegetables may decrease the risk of asthma after 1 y of life, whereas allergic sensitization at school age seemed to increase with extra vitamin and cod liver oil supplements during infancy. Living area influenced allergic sensitization, with differences between coastal and inland areas.     

Bronchial asthma and wheeze in a desert country

A cross-sectional, population-based study was conducted among school children (3300), aged 7–12 years, in the Kingdom of Saudi Arabia, during the period January, 1988–February, 1990. The aim of the study was to investigate the association between asthma, allergic rhinitis, wheeze and eczema among Saudi school children. The relationship between pet-ownership and respiratory allergy was also studied. Detailed information was collected about wheeze and asthma in 3041 children and history of asthma and allergic rhinitis in their parents. The population sample had a high prevalence rate of diagnosed asthma (6.8%), history of wheeze (10.5%), allergic rhinitis (17.9%), and eczema (10.8%). Allergic rhinitis was the most frequently seen respiratory illness when compared to other respiratory symptoms. The prevalence rate of asthma, allergic rhinitis and eczema among parents reflected the same pattern as that seen in the children. Prevalence rate for asthma in children with pets is twice that of children without pets (OR:2.4; 95%, Cl:1.8–3.1). The odds of having chronic cough (OR:3.9; 95%, Cl:2.8–5.2), chronic wheeze (OR:4.2; 95%, 3.3–5.4), allergic rhinitis (OR:8.0; 95% Cl:6.3–10.3) and eczema (OR:2.8:95 Cl:2.1–3.7) was higher in children with pets than in children without pets. The present study revealed that petownership was associated with increased respiratory symptoms.     

Does heredity modify the association between farming and allergy in children?

AIM: It has been suggested that living on a farm decreases the risk of childhood allergy, especially if farming involves livestock. The aim of this study was to examine the association between farming and allergy in children, and the influence of atopic heredity in this association. METHODS: The cross-sectional data of the 7981 children aged 13-14 y who participated in the Finnish ISAAC study between the years 1994 and 1995 were used to evaluate the association between farming and allergy. RESULTS: Living on a farm was associated with a decreased risk of current symptoms of allergic rhinoconjunctivitis among all children (aOR 0.79; 95% CI 0.63, 0.99), and with a decreased risk of hay fever, especially among those children with a parental history of hayfever (aOR 0.60; 95% CI 0.40-0.89, p = 0.072 for interaction). The children of farmers with a history of hay fever also had a decreased risk of current wheeze (aOR 0.38; 95% CI 0.12-1.24, p = 0.040 for interaction). No significant association was found between farming and either asthma or eczema. Children living on a farm with livestock had the lowest risk of allergic rhinoconjunctivitis (aOR 0.69), followed by those living on a farm without livestock (aOR 0.89) compared with the non-farming children (p-value for trend 0.024). CONCLUSION: Our results support the recent findings on a decreased risk of allergy among the children living on farms. A possible differential effect of parental history of hay fever on the relation of farming environment and the risk of allergic symptoms warrant further investigation.     

Asthma phenotypes in childhood: lessons from an epidemiological approach

Asthma is a heterogenous disease with variable signs and symptoms among patients. It also presents significant individual variability over time. Recently, some important population-based studies that followed children from birth or from early childhood into adulthood have shed new light on how we understand this syndrome. Three phenotypes have been identified in children with asthma: transient wheezing, non-atopic wheezing of the toddler and pre-school-aged child and IgE-mediated wheezing. Transient wheezing is associated with symptoms that are limited to the first 3-5 years of life, decreased lung function, maternal smoking during pregnancy and exposure to other siblings or children at daycare centres. There is no association between transient wheezing and family history of asthma or allergic sensitisation. Children wheezing with respiratory syncytial virus in the first years of life are more likely to be wheezing up to 13 years of age; this is independent of atopy (non-atopic wheezers) and is not related to atopic sensitisation. Wheezing associated with evidence of allergic sensitisation has been identified as the 'classic' asthma phenotype. Early allergic sensitisation is a major risk factor for persistent asthma.     

The Natural History of IgE Sensitisation and Atopic Disease in Early Childhood

ABSTRACT. We have prospectively followed 57 children of atopic parents up to 5 years of age, documenting clinical atopic disease and allergen skin test reactions. The cumulative prevalences of the clinical features of atopic disease over the 5 years were: atopic dermatitis (58%), wheeze (49%), recurrent wheeze (33%), rhinitis (68%) and immediate food reactions (18%). Atopic dermatitis and immediate food reactions predominated in infancy (birth to 20 months) while wheezing was more prominent in later childhood (20 months to 5 years). Rhinitis was common in both infancy and childhood. IgE sensitisation to ingested allergens was prominent in early infancy and was usually transient. Inhaled allergen sensitisation occurred later in infancy and was generally permanent with wheal sizes tending to increase with age. There was a significant association between IgE sensitisation to ingested but not inhaled allergens and all atopic manifestations in infancy, with the exception of rhinitis. In contrast IgE sensitisation to inhaled allergens was associated with rhinitis and wheeze in later childhood. We found two clinical groups. One group, with only ingested allergen sensitisation had a high incidence of atopic dermatitis but low incidence of respiratory symptoms at 5 years of age. The other group, who developed evidence of IgE sensitisation to inhaled allergens, had a high incidence of rhinitis and wheeze but low incidence of atopic dermatitis at 5 years of age.     

The natural history of IgE sensitisation and atopic disease in early childhood

We have prospectively followed 57 children of atopic parents up to 5 years of age, documenting clinical atopic disease and allergen skin test reactions. The cumulative prevalences of the clinical features of atopic disease over the 5 years were: atopic dermatitis (58%), wheeze (49%), recurrent wheeze (33%), rhinitis (68%) and immediate food reactions (18%). Atopic dermatitis and immediate food reactions predominated in infancy (birth to 20 months) while wheezing was more prominent in later childhood (20 months to 5 years). Rhinitis was common in both infancy and childhood. IgE sensitisation to ingested allergens was prominent in early infancy and was usually transient. Inhaled allergen sensitisation occurred later in infancy and was generally permanent with wheal sizes tending to increase with age. There was a significant association between IgE sensitisation to ingested but not inhaled allergens and all atopic manifestations in infancy, with the exception of rhinitis. In contrast IgE sensitisation to inhaled allergens was associated with rhinitis and wheeze in later childhood. We found two clinical groups. One group, with only ingested allergen sensitisation had a high incidence of atopic dermatitis but low incidence of respiratory symptoms at 5 years of age. The other group, who developed evidence of IgE sensitisation to inhaled allergens, had a high incidence of rhinitis and wheeze but low incidence of atopic dermatitis at 5 years of age.     

Respiratory infections in schoolchildren: co-morbidity and risk factors.

AIMS: To assess co-morbidity and risk factors for otitis media, tonsillopharyngitis, and lower respiratory infections in school children. METHODS: Logistic regression analysis of co-morbidity and risk factors for airway infections in a population based sample of 10 year old children living in Oslo, Norway. MAIN OUTCOME MEASURES: otitis media, tonsillopharyngitis, and lower respiratory infections in past 12 months. RESULTS: Airway infections in 10 year old children were common, and significant co-morbidity was found between the various airway infections. Home dampness was a risk factor for all infections, adjusted odds ratios ranging from 1.2 (95% CI 1.0 to 1.5) to 1.4 (95% CI 1.1 to 1.6) for otitis media and tonsillopharyngitis respectively. Atopic disease was a constitutional risk factor, particularly strong for lower airway infections (adjusted odds ratio 2.4, 95% CI 1.8 to 3.1). African or Asian ethnicities were associated with the airway infections, adjusted odds ratios ranging from 1.2 (95% CI 0.9 to 1.7) to 1.7 (95% CI 1.2 to 2.3). CONCLUSIONS: Respiratory tract infections were common in 10 year old children. There was substantial co-morbidity between upper and lower airway infections. Environmental and constitutional factors were identified and positively associated with the infections. Results support the hypothesis of 1957 that the whole respiratory tract is one unit.     

Prevalence of allergy-related symptoms in Singaporean children in the second year of life

This study describes the cross-sectional prevalence of symptoms associated with eczema (chronic itchy rash), asthma (wheeze), and allergic rhinitis (rhinoconjunctivitis) in 1026 subjects between 18.5 and 23 months old (median age is 21 months) in Singapore. The first 2 yr cumulative prevalence of chronic itchy rash, wheeze, and rhinoconjunctivitis were 22.1% (n=227), 22.9% (n=235), and 8.4% (n=86) respectively. In total, 42.2% (414 of 979) reported ever having any of these symptoms. Eczema, although prevalent, was diagnosed only in 34.4% (n=78) of children with chronic itchy rash. Children with this eczematous rash were also more prone to wheeze (cOR=2.0, 95% CI: 1.2-3.0) and rhinoconjunctivitis (cOR=2.0, 95% CI: 1.4-2.8). Similarly, subjects who reported rhinoconjunctivitis and chronic itchy rash were 2.4 times (95% CI: 1.6-3.6) and 1.4 times (95% CI: 1.0-2.0) more at risk of wheezing respectively. Family history of allergy was a significant risk factor for chronic itchy rash (aOR=1.8, 95% CI: 1.3-2.4) and wheeze (aOR=1.7, 95% CI: 1.3-2.4). Thus, symptoms related to allergy were already prevalent during the second year of life. Significant proportions of these symptoms are likely to be due to true atopy as strong relationship with familial history and comorbidity with other potential allergic symptoms were observed.     

Role of atopy in the natural history of wheeze and bronchial hyper-responsiveness in childhood

The role of atopy in the development of asthma has become increasingly recognised. We have been prospectively following a birth cohort of children of atopic parents to document the development of atopic disease. Our aim in this study was to document the natural history of BHR and wheeze at 10 years of age and to relate this to atopy. We reviewed 47 of our original cohort of 79 infants at 10 years of age and documented their clinical history of atopic disease and performed allergen skin prick tests and BHR to histamine. Thirty-three (70%) children wheezed at some time during their 10 years of life, with 13 commencing in infancy. Twenty-two children (47%) had current wheeze at 10 years of age. Wheeze in infancy was a poor predictor (RR 1.23, Cl₉₅ 0.66–2.23) of current wheeze while wheeze commencing after infancy was a good predictor (RR 2.89, Cl₉₅ 1.45–5.2). In contrast both atopy in infancy (RR 2.94, Cl₉₅ 1.92–4.53) and current atopy (RR 3.58, Cl₉₅ 1.43–9.03) were strong predictors of current wheeze. Analysis of BHR confirmed the importance of atopy in predicting its occurrence and severity. Sensitisation to D. pteronyssinus appeared to be the strongest predictor of both current wheeze and BHR. These observations confirm the importance of atopy in predicting outcome in children with asthma and suggest that wheezing in infancy and wheezing in later childhood may have different pathogenetic mechanisms.     

Timing of infection and development of wheeze,eczema, and atopic sensitization during the first 2 yr of life: The KOALA Birth Cohort Study

Mommers M, Thijs C, Stelma F, Penders J, Reimerink J, van Ree R, Koopmans M. Timing of infection and development of wheeze, eczema, and atopic sensitization during the first 2 yr of life: The KOALA Birth Cohort Study.
Pediatr Allergy Immunol 2010: 21: 983–989.
© 2010 The John Wiley & Sons A/S To investigate if infections in pregnancy and very early in life present a risk for wheezing, eczema, or atopic sensitization in later infancy. A total of 2319 children enrolled before birth in the KOALA Birth Cohort Study were followed during their first 2 yr of life using repeated questionnaires. Information was obtained on common colds, fever, and diarrhea with fever as well as on wheeze and eczema at ages 3 and 7 months and 1 and 2 yr, respectively. Blood samples were collected from 786 children at age 2 yr for specific immunoglobulin E analyses. Children with a common cold [adjusted odds ratio (aOR) 2.03 95% CI 1.21–3.41] or fever episode (aOR 1.81 95% CI 1.10–2.96) in the first 3 months of life had a higher risk of new onset wheeze in the second year of life compared to children who had not. For children with diarrhea with fever in the first 3 months of life, the aOR for new onset wheeze in the second year of life was 3.94 (95% CI 1.36–11.40) compared to children without diarrhea. Infections becoming clinically manifest during the first 3 months of life may be a general marker for a wheezy phenotype.     

Current cat ownership may be associated with the lower prevalence of atopic dermatitis, allergic rhinitis, and Japanese cedar pollinosis in schoolchildren in Himeji, Japan

The aim of the study was to clarify the relationship between current pet ownership, passive smoking, and allergic diseases among the Japanese children. From 1995 to 2001, we distributed the Japanese edition of the questionnaire of the American Thoracic Society and the Division of Lung Diseases (ATS-DLD) to survey allergic diseases among 35,552 6-yr-old children at primary school in the city of Himeji, Japan. We analyzed the data by multiple logistic regression and calculated adjusted odds ratios for environmental factors, including passive smoking and pet (dog and/or cat) ownership. There were no significant relationships between the prevalence of asthma and current pet ownership and passive smoking. However, current cat ownership was related to a significantly lower prevalence of atopic dermatitis [adjusted odds ratio (aOR) 0.79, 95% confidence interval (CI) 0.67-0.93], allergic rhinitis (aOR: 0.71, 95% CI 0.57-0.89) and Japanese cedar pollinosis (aOR 0.57, 95% CI 0.44-0.75). Strikingly, passive smoking was also related to a significantly lower prevalence of allergic rhinitis (aOR 0.83, 95% CI 0.77-0.89) and Japanese cedar pollinosis (aOR 0.81, 95% CI 0.74-0.88). Current cat ownership was associated with a lower prevalence of atopic dermatitis, allergic rhinitis, and Japanese cedar pollinosis. In addition, passive smoking was also associated with a lower prevalence of allergic rhinitis and Japanese cedar pollinosis.     

Respiratory infections in schoolchildren: co-morbidity and risk factors

Aims

To assess co‐morbidity and risk factors for otitis media, tonsillopharyngitis, and lower respiratory infections in school children.

Methods

Logistic regression analysis of co‐morbidity and risk factors for airway infections in a population based sample of 10 year old children living in Oslo, Norway. Main outcome measures: otitis media, tonsillopharyngitis, and lower respiratory infections in past 12 months.

Results

Airway infections in 10 year old children were common, and significant co‐morbidity was found between the various airway infections. Home dampness was a risk factor for all infections, adjusted odds ratios ranging from 1.2 (95% CI 1.0 to 1.5) to 1.4 (95% CI 1.1 to 1.6) for otitis media and tonsillopharyngitis respectively. Atopic disease was a constitutional risk factor, particularly strong for lower airway infections (adjusted odds ratio 2.4, 95% CI 1.8 to 3.1). African or Asian ethnicities were associated with the airway infections, adjusted odds ratios ranging from 1.2 (95% CI 0.9 to 1.7) to 1.7 (95% CI 1.2 to 2.3).

Conclusions

Respiratory tract infections were common in 10 year old children. There was substantial co‐morbidity between upper and lower airway infections. Environmental and constitutional factors were identified and positively associated with the infections. Results support the hypothesis of 1957 that the whole respiratory tract is one unit.     

Smoking in parents of children with asthma and bronchiolitis in a pediatric emergency department

OBJECTIVES: To determine smoking habits, levels of nicotine-addiction, readiness to quit, and beliefs about the effects of environmental tobacco smoke (ETS) of parents of children with bronchiolitis and asthma who present to a children's emergency department (ED). DESIGN/METHODS: This was a cross-sectional prevalence study of parents or legal guardians of children with asthma or bronchiolitis presenting to a pediatric ED. RESULTS: Two hundred forty-nine parents/legal guardians comprised the study group. The mean age (+/-SD) was 30.0 (+/-8.9) years; 88% were female; 51% were nonwhite; 37% were educated beyond high school. The self-reported smoking prevalence was 41% (95% CI = 32-51). Smoking prevalence among parents of wheezing children varied according to education, income, and race, but not according to gender, age, or employment status. Of the 102 smokers in the sample, 84 (82.4%, 95% CI = 73-88) reported that they wanted to quit; 78 (76.5%, 95% CI = 68-84) stated that they wanted to quit within the next month. Forty-nine percent (95% CI = 39-59) scored above 4 on the Fagerstrom Test for Nicotine Dependence and were considered nicotine-dependent. The majority of smokers admitted to smoking around their children (66.7%, 95% CI = 57-75). Many parents knew that ETS might contribute to the development of the following illnesses: colds/upper respiratory tract infections - 77.5%, otitis media - 68.6%, pneumonia - 50%, wheezing/asthma attacks - 86.3%, and SIDS - 31.4%. CONCLUSION: The prevalence of smoking and nicotine addiction among parents of children with asthma or bronchiolitis who bring their children to a pediatric ED is high. Many parents have some knowledge about the effects of ETS, and the majority would like to quit. Future studies to help determine the best way to deliver advice to parents on ETS exposure reduction and smoking cessation are warranted.     

Birth anthropometric measures, body mass index and allergic diseases in a birth cohort study (BAMSE).

OBJECTIVE: We aimed to assess increased birth weight or birth length in relation to allergic diseases at 4 years of age, taking body mass index (BMI) at age 4 as a covariate in the adjustment. METHODS: The parents of a large prospective birth cohort answered questionnaires on environmental factors and allergic symptoms when their children were 2 months and 1, 2 and 4 years old. Perinatal data on weight and length at birth were received from the child care health centres. The children were clinically examined at 4 years of age and height and weight recorded. Blood was drawn for analysis of specific IgE antibodies to common inhalant allergens. Risk associations between birth anthropometric measures and wheeze, allergic diseases or sensitisation were estimated in multivariate logistic regression analyses (n = 2869). RESULTS: There were no clear overall associations between birth weight and allergic diseases at 4 years of age. Birth length > or =90th percentile was inversely associated with any wheeze at age 4 (adjusted OR 0.64, 95% CI 0.44 to 0.92) but was significantly associated only with late-onset wheeze (adjusted OR 0.40, 95% CI 0.21 to 0.77). No such associations were seen for persistent or transient wheeze, eczema, rhinitis or allergic sensitisation. Transient wheeze during the first 2 years of age tended to be associated with increased BMI at age 4. CONCLUSION: Increased birth weight was not associated with wheeze or allergic disease. Increased birth length may play a protective role in late-onset wheeze in early childhood.     

Metachromatic cells and eosinophils in atopic children A prospective study

Metachromatic cells and eosinophil leukocytes were studied prospectively in 64 newborns with and without a family history of atopic disease (FH). Cell findings in nasal mucosa and peripheral blood were related to development of atopic symptoms up to 18 months of age. For this purpose, a gentle scraping method suitable for infants was developed. Nasal metachromatic cells were more prevalent in atopic than in non-atopic infants. The cells were found in infants with respiratory allergy as well as in infants with eczema. Non-atopic infants with metachromatic cells all had FH. The cells were detected prior to, or at the time of diagnosis. Thus, metachromatic cells are associated with atopic propensity as defined by development of atopic disease and/or a FH. Infants with respiratory allergy more frequently had acute otitis media than infants with eczema and non-atopic infants. Presence of nasal metachromatic cells was associated with increased middle-ear morbidity in atopic and non-atopic infants, and high cell scores correlated with high frequency of otitis media. Infants with respiratory allergy may have otitis media as a result of the allergic condition. Blood eosinophils were studied in 154 infants and were found to decrease with age. Blood eosinophilia at 3 months preceded atopic development but was not associated with FH. Nasal eosinophilia was a common finding in atopic and non-atopic infants. In conclusion, presence of nasal metachromatic cells and blood eosinophilia is associated with atopic disease, even before the appearance of clinical symptoms.     

Increasing prevalence of allergic rhinitis but not asthma among children in Hong Kong from 1995 to 2001 (Phase 3 International Study of Asthma and Allergies in Childhood)

There is a worldwide belief that the prevalence of asthma and other allergic diseases is increasing but the measures used in many studies are susceptible to systematic errors. We examined the trend of asthma, allergic rhinitis and eczema prevalence in school children aged 6–7 years in Hong Kong from 1995 to 2001 using standardized ISAAC methodology. There were 4448 and 3618 children participating in 2001 and 1995, respectively. The prevalence of life-time rhinitis (42.4% vs. 38.9%, p < 0.01), current rhinitis (37.4% vs. 35.1%, p < 0.03), current rhinoconjunctivitis (17.2 vs. 13.6%, p < 0.01) and life-time eczema (30.7% vs. 28.1%, p = 0.01) increased significantly. There was no significant change in prevalence of life-time asthma, life-time wheeze and current wheeze albeit a significant increase in severe asthma symptoms. We investigated a number of potential risk factors including sex, family history of atopy, sibship size, birth weight, respiratory tract infections, pet ownership and exposure to tobacco smoke. However, the increases in prevalence of rhinitis and eczema could not be entirely explained by the change of prevalence of these risk factors. The odds ratio OR for the study period remained significantly associated with current rhinitis (OR 1.31, 95% confidence intervals CI 1.17–1.46), current rhinoconjunctivitis (OR 1.63, 95% CI 1.41–1.87) and life-time eczema (OR 1.30, 95% CI 1.16–1.45) after adjustment for these confounding variables using logistic regression model. Further study is warranted to elucidate the factors contributing to the observable change in the prevalence of rhinitis in our population.