Pet-keeping in childhood and adult asthma and hay fever: European community respiratory health survey

BACKGROUND: Whether pet-keeping early in life protects against or promotes allergy remains unclear. OBJECTIVE: Our aim was to examine the effects of childhood pet-keeping on adult allergic disease in a large international population-based study, including information on sensitization, adult pet-keeping, and pet prevalence in the populations. METHODS: We used information from structured interviews (n = 18,530) and specific IgE to common aeroallergens in blood samples (n = 13,932) from participants in the European Community Respiratory Health Survey (ECRHS) to analyze the associations between keeping pets and adult asthma and hay fever. RESULTS: Keeping cats in childhood was associated with asthma only among atopic subjects, an association that varied between centers (P =.002) and was stronger where cats where less common (< 40% cats: odds ratio(wheeze) [OR(wheeze)] = 1.84, 95% CI = 1.31-2.57; 40%-60% cats: OR(wheeze) = 1.33, 95% CI = 1.10-1.61; > or =60% cats: OR(wheeze) = 0.98, 95% CI = 0.73-1.33). Dogs owned in childhood or adulthood were associated with asthma among nonatopic subjects (childhood: OR(wheeze) = 1.28, 95% CI = 1.13-1.46; adulthood: OR(wheeze) = 1.31, 95% CI = 1.14-1.51; both: OR(wheeze) = 1.69, 95% CI = 1.40-2.04). In atopic subjects, those who had owned dogs in childhood had less hay fever (OR = 0.85; 95% CI = 0.73-0.98) and no increased risk of asthma (OR(wheeze) = 1.01, 95% CI = 0.87-1.17). Respiratory symptoms were more common in subjects who had owned birds during childhood (OR(wheeze) = 1.12; 95% CI = 1.02-1.23) independent of sensitization. CONCLUSIONS: The effects of pet-keeping in childhood varied according to the type of pet, the allergic sensitization of the individual, and the wider environmental exposure to allergen. Cats owned in childhood were associated with more asthma in sensitized adults who grew up in areas with a low community prevalence of cats. Dogs owned in childhood seemed to protect against adult allergic disease but promote nonallergic asthma.     

Relationship between childhood atopy and wheeze: what mediates wheezing in atopic phenotypes?

BACKGROUND: The nature of the relationship between childhood wheeze and atopy remains uncertain. OBJECTIVE: To characterize childhood wheeze among atopic phenotypes in a longitudinal birth cohort study. METHODS: A whole population birth cohort (N = 1,456) was recruited in 1989. Children were seen at birth and at 1, 2, 4, and 10 years of age to obtain information on asthma and allergic disease development and relevant risk factors for these states. Skin prick testing at ages 4 (n = 980) and 10 (n = 1,036) years was used to define atopic phenotypes. Wheezing in these states was characterized, and logistic regression was used to identify independent risk factors for wheeze onset in different atopic phenotypes. RESULTS: Wheeze ever occurred in 37% of never atopics, 38% of early childhood atopics, 65% of chronic childhood atopics, and 52% of delayed childhood atopics. Chronic childhood atopics had significant wheezing morbidity and bronchial hyperresponsiveness. Their wheezing was associated with male sex, early eczema, family history of eczema, and early tobacco exposure. Never atopic wheeze was related to maternal asthma, parental smoking, and respiratory tract infections. Exclusive breastfeeding protected against early childhood atopic wheeze. Maternal asthma, family history of urticaria, and dog ownership increased delayed childhood atopic wheeze. CONCLUSIONS: In many respects, chronic childhood atopy is the atopic phenotype associated with the most significant forms of childhood wheezing. In such children, heritable drive, allergens, and synergy with other environmental triggers seem to be crucial determinants of wheeze onset. Where such sensitization is absent, numerous environmental factors plus genetic predisposition may assume importance for wheezing.     

Mouse exposure and wheeze in the first year of life.

BACKGROUND: Studies have found that exposure to mice is highly prevalent among children with asthma living in urban areas. OBJECTIVE: To examine the relationship between exposure to mice and wheeze in the first year of life. METHODS: We conducted an ongoing prospective birth cohort study of 498 children with a history of allergy or asthma in at least 1 parent living in metropolitan Boston (the Home Allergens and Asthma Study). RESULTS: In a multivariate analysis, infants whose parents reported exposure to mice in the household had nearly twice the odds of developing any wheeze in the first year of life as children without exposure (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.14-2.95; P = .01). Other variables associated with wheeze in the first year of life included low birth weight (OR, 1.77; 95% CI, 1.06-2.95; P = .03), having at least 1 lower respiratory tract illness (OR, 5.59; 95% CI, 3.46-9.04; P < .001), exposure to high levels of endotoxin at age 2 to 3 months (fourth quartile compared with first quartile: OR, 2.32; 95% CI, 1.19-4.54; P = .01), and exposure to cockroach allergen of 0.05 U/g of dust or more at age 2 to 3 months (OR, 1.83; 95% CI, 1.09-3.08; P = .02). CONCLUSION: Among children with a parental history of asthma or allergies, exposure to mice is associated with wheeze in the first year of life, independent of other factors.     

Does previous infection protect against atopic eczema and recurrent wheeze ininfancy?

BACKGROUND: Frequent infection in infancy and early childhood has been hypothesized to explain the low prevalence of asthma and other atopic disease among children in developing countries (the so-called 'hygiene hypothesis'), but the low prevalence in Eastern Europe remains unexplained. OBJECTIVE: To test the hygiene hypothesis in the Republic of Belarus by examining the relationship between gastrointestinal (GI) and respiratory infection and two potentially atopic outcomes in the first 12 months of life: atopic eczema and recurrent wheeze. METHODS; We carried out two case-control studies nested within a large (n=17 046) randomized trial in Belarus, with cases defined as (1) first occurrence of atopic eczema (n=819) and (2) second episode of wheezing (n=112). Incidence density sampling was used to select four matched controls born within 1 month at the same hospital as the case. Exposure was defined as one or more episodes of GI or respiratory infection (examined separately) with onset >7 days before onset of the case's atopic outcome. Analyses controlled for family atopic history, duration of exclusive breastfeeding, sex, birth weight, maternal education, and (for recurrent wheeze) maternal smoking. RESULTS: For atopic eczema, prior GI infection occurred in 7.4% of cases vs. 6.0% of controls [adjusted OR=1.27 (0.94-1.72)] and prior respiratory infection in 35.2% vs. 32.6% [adjusted OR=1.14 (95% CI=0.94-1.37)]. For recurrent wheeze, prior GI infection occurred in 9.8% of cases vs. 7.4% of controls [adjusted OR=1.30 (0.60-2.82)]. CONCLUSION: Our results do not support the hypothesis that infection protects against atopic eczema or recurrent wheezing in the first 12 months of life.     

Number of offspring and maternal allergy

The consistent association seen between family size and childhood allergy has led to the 'hygiene hypothesis', namely that a lower frequency of infections in early childhood is associated with an increased risk of asthma and hay fever. Maternal atopy, however, is a strong predictor of childhood asthma and hay fever. If maternal atopy is inversely related to the number of siblings then the role of siblings in the development of childhood atopy, the basic tenet of the 'hygiene hypothesis', is challenged. We evaluated the association between number of pregnancies and number of live births with lifetime occurrence of maternal wheeze, asthma, allergic rhinitis, and allergic conjunctivitis in a cross-sectional study in four areas in Italy. A total of 1755 (35-74 year old) nonsmoking women filled a questionnaire on reproductive history as well as on lifetime occurrence of symptoms/diseases. The number of live births was inversely related to lifetime allergic rhinitis (P-value for trend=0.031) and allergic conjunctivitis (P-value for trend=0.011). The odds ratios for those with 4+ children (in comparison with those having 0-1) were: 0.53 (95% CI: 0.27-1.04) and 0.42 (95% CI: 0.22-0.81), respectively. A similar trend was seen for number of pregnancies, although not statistically significant. No association was found between number of pregnancies and number of live births with wheeze or asthma. The results may be interpreted as an indication that maternal atopy influences pregnancy outcomes or that pregnancy itself has an effect on maternal atopy.     

The association of early life exposure to antibiotics and the development of asthma,eczema and atopy in a birth cohort: confounding or causality?

Background In general, studies reporting positive associations between antibiotic exposure and respiratory and allergic disease have been unable to determine the nature of this association.
Objective To examine the association between antibiotic exposure in infancy and the development of asthma, eczema and atopy in early childhood.
Methods In a birth cohort study, we collected reported antibiotic exposure before 3 months and before 15 months along with outcomes (wheeze, asthma, eczema, rash, inhaler use) at 15 months ( n =1011) and 4 years ( n =986). Atopy was measured using skin prick tests at 15 months.
Results We found significant univariate associations of antibiotic exposure before 3 months with asthma developing between birth and 15 months [OR 2.32 (95% CI 1.45–3.69)]. After adjustment for chest infections, this association reduced (OR=1.58, 95% CI 0.96–2.60) becoming marginally significant ( P =0.07). A marginally significant association of antibiotics with atopy (OR=1.44, 95% CI 0.96–2.14) in the univariate analysis also reduced after adjustment for chest infections (OR=1.36, 95% CI 0.91–2.05). There was no effect of antibiotic exposure before 15 months on asthma developing after 15 months and present between 3 and 4 years (OR=1.35 95% CI 0.85–2.14). Antibiotic exposure before 3 months was not associated with eczema and rash developing between birth and 15 months but exposure before 15 months was related to eczema [OR 1.83 (95% CI 1.10–3.05)] and rash [OR 1.61 (95% CI 1.02–2.53)] developing after 15 months and remaining present at 4 years. These effects reduced in the multivariate analysis.
Conclusions Our findings suggest that the effect of antibiotics on respiratory disease may be due to confounding by chest infections at an early age when asthma may be indistinguishable from infection.     

Wheezing, asthma, hayfever, and atopic eczema in childhood following exposure to tobacco smoke in fetal life

BACKGROUND: Prenatal maternal smoking has been associated with adverse respiratory effects in childhood such as lung deficits and wheezing, but results concerning asthma, hayfever, and atopic eczema are inconsistent. OBJECTIVE: In the present study, we investigate the effects of maternal smoking in pregnancy on asthma, hayfever, atopic eczema, and wheezing in the offspring up to the age of 14-18. METHODS: The study was based on a cohort of mothers enrolled during midwife visits around the 36th week of gestation in Odense and Aalborg, Denmark, 1984-1987. Singleton, live born children (n = 11,144) were followed-up in 2002 to obtain a childhood history of atopic diseases, by means of questionnaires to the parents. Multivariate logistic regression analyses for medical diagnoses of asthma, hayfever, atopic eczema, and symptoms of wheezing before the age of 3, were carried out on 7844 children. RESULTS: After adjustment for confounders, late prenatal smoke exposure was associated with wheezing, with an odds ratio (OR) of 1.2, and a 95% confidence interval (CI) of 1.1-1.5. Furthermore, slightly reduced estimates for hayfever (OR 0.8, CI 0.7-1.0) and atopic eczema (OR 0.8, CI 0.7-0.9) were obtained for children exposed in late pregnancy compared with non-exposed. CONCLUSION: Late gestational smoke exposure was associated with wheezing but not with asthma, while null or even protective estimates were indicated for hayfever and atopic eczema. However, lack of control options for hereditary factors may have affected the results.     

Endogenous and exogenous sex steroid hormones and asthma and wheeze in young women

BACKGROUND: Emerging evidence suggests that both endogenous and exogenous sex steroid hormones may influence the occurrence of asthma and wheeze among women. OBJECTIVE: We investigated the associations between exogenous sex hormone (oral contraceptive [OC]) use and wheezing in young women with and without asthma history. To investigate the role of endogenous sex hormones, we examined the association between age at menarche and the development of asthma after puberty. METHODS: We conducted a study among 905 women who had undergone menarche. Subjects were between 13 and 28 years of age and had participated in the Children's Health Study. RESULTS: In women without asthma, OC use was associated with higher risk of current wheeze (odds ratio [OR], 1.75; 95% CI, 1.15-2.65). In contrast, OC use was associated with a markedly reduced prevalence of current wheeze in women with a history of asthma (OR, 0.18; 95% CI, 0.06-0.56; P value for interaction = .003). These associations showed significant trends with duration of OC use. Age at menarche was associated with new-onset asthma after puberty. Compared with women who had menarche after age 12 years, women with menarche before age 12 years had a 2.08-fold (95% CI, 1.05-4.12) higher risk of asthma after puberty. CONCLUSION: Both endogenous and exogenous sex steroid hormones affect asthma and wheeze occurrences in young women. CLINICAL IMPLICATIONS: Because women have higher asthma risk after puberty, and OC use is common among young women, clinicians may inform women with asthma about the potential effects of OC on asthma-related respiratory symptoms.     

Maternal smoking increases risk of allergic sensitization and wheezing only in children with allergic predisposition: longitudinal analysis from birth to 10 years

Background:  The role of passive smoking for allergies and asthma in children above the age of 3 years remains unclear and possible interactive effects with parental allergies have not been formally evaluated in long-term studies. To examine the interaction of passive smoking and an allergic predisposition regarding allergic sensitization, allergic airway symptoms and respiratory infections during the first 10 years of life.
Methods:  In a prospective multicenter birth cohort study with 1314 recruited children in Germany, we assessed serum immunoglobulin E against common allergens at seven time points, and parental smoking and respiratory symptoms annually by using questionnaires. Longitudinal analyses were performed using generalized estimating equation models (stratified by parental allergy status).
Results:  During the first 10 years, 18% of the children were exposed to regular maternal smoking since pregnancy, 43% to irregular maternal or only paternal smoking. Among children with two allergic parents, a mother who smoked regularly significantly increased the odds for allergic sensitization (adjusted OR 4.8, 95% CI 1.3–18.2) and wheezing (adjusted OR 5.7, 95% CI 1.7–19.0) in her child compared with children who were never exposed. For those with only one allergic parent, the odds were doubled and also statistically significant, whereas in children without allergic parents maternal smoking had no effects. There was no association of maternal smoking with allergic rhinitis or respiratory infections.
Conclusions:  Our results suggest that regular maternal smoking is a strong risk factor for allergic sensitization and asthma symptoms during the first 10 years of life, but only in children with allergic parents.     

Caesarean section delivery and the risk of allergic disorders in childhood

BACKGROUND: The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C-sections). OBJECTIVE: To determine whether children born by C-section have a different risk of allergic disorders compared with those delivered vaginally. We also tested the hypothesis that the risk of allergic disorders is highest for children born after 'repeat C-sections'. METHODS: A retrospective cohort study of 8,953 children aged 3-10 years. Children diagnosed with allergic rhinoconjunctivitis (AR), asthma, atopic dermatitis (AD), or food allergies were identified from the Kaiser Permanente Northwest Region electronic records. The children's sex, birth weight, birth order, postnatal exposure to antibiotics as well as the mothers' age, ethnicity, education, marital status, smoking status during pregnancy, and use of asthma or hayfever medications were identified through the mothers' medical records or through the Oregon Birth Registry. RESULTS: The risk of being diagnosed with AR was significantly higher in the children born by C-section than in those delivered vaginally: adjusted odds ratio (OR)=1.37%, 95% confidence interval (CI)=1.14-1.63. Delivery by C-section was also associated with the subsequent diagnosis of asthma (OR=1.24%, 95% CI=1.01-1.53); this association was gender specific, with a positive association restricted to girls (OR for asthma in girls: OR=1.53%, 95% CI=1.11-2.10; in boys: OR=1.08%, 95% CI=0.81-1.43). There was no significant association between mode of delivery and AD. If children born in a 'repeat C-section' were considered separately the risk of being diagnosed with AR increased further (OR=1.78%, 95% CI=1.34-2.37). The same increase was noted for asthma in girls (OR=1.83%, 95% CI=1.13-2.97) but not in boys. CONCLUSION: Caesarean sections may be associated with an increased risk of developing AR in childhood.     

Early-life respiratory viral infections, atopic sensitization, and risk of subsequent development of persistent asthma

BACKGROUND: Severe lower respiratory infections (LRIs) and atopic sensitization have been identified as independent risk factors for asthma. OBJECTIVE: The nature of potential interactions between these risk factors was the subject of this study. METHODS: A community-based cohort of 198 children at high atopic risk was followed from birth to 5 years. All episodes of acute respiratory illness in the first year were recorded and postnasal aspirates were collected for viral identification. History of wheeze and asthma was collected annually, and atopy was assessed at 6 months, 2 years, and 5 years. RESULTS: A total of 815 episodes of acute respiratory illness were reported, and 33% were LRIs. Viruses were detected in 69% of aspirates, most commonly rhinoviruses (48.3%) and respiratory syncytial virus (10.9%). At 5 years, 28.3% (n = 56) had current wheeze, and this was associated with wheezy [odds ratio (OR), 3.4 (1.2-9.7); P = .02] and/or febrile LRI [OR, 3.9 (1.4-10.5); P = .007], in particular those caused by respiratory syncytial virus or rhinoviruses [OR, 4.1 (1.3-12.6); P = .02]. Comparable findings were made for current asthma. Strikingly these associations were restricted to children who displayed early sensitization (< or =2 years old) and not observed in nonatopic patients or those sensitized later. CONCLUSION: These data suggest viral infections interact with atopy in infancy to promote later asthma. Notably the occurrence of both of these events during this narrow developmental window is associated with maximal risk for subsequent asthma, which suggests a contribution from both classes of inflammatory insults to disease pathogenesis. CLINICAL IMPLICATIONS: Protection of "high-risk" children against the effects of severe respiratory infections during infancy may represent an effective strategy for primary asthma prevention. The potential benefits of these strategies merit more careful evaluation in this age group.     

Interaction between early maternal smoking and variants in TNF and GSTP1 in childhood wheezing

Background Children exposed to tobacco smoke early in life have a higher risk of wheeze. Individual susceptibility may depend on genetic factors. Objective We studied whether variations in single nucleotide polymorphisms (SNPs) in the TNF, glutathione S transferase P1 (GSTP1) and β2‐adrenoreceptor (ADRB2) genes modify the effect of early maternal smoking on the development of childhood asthma, wheeze and allergic sensitization. Methods In the Swedish prospective birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiological Survey) (n=4089), data collection included questionnaires to measure tobacco smoke exposure and clinical outcomes up to age 4 and medical examinations with blood sampling for specific IgE measurements and genotyping. We defined early maternal smoking as daily smoking by the mother during pregnancy and/or postnatally. We investigated five TNF, six GSTP1 and three ADRB2 SNPs in 982 selected wheezers and non‐wheezers. Results An interaction with early maternal smoking was found for three TNF SNPs (?857C/T, Intron 1, Intron 3) with respect to early wheeze (up to 2 years of age). For example, the odds ratio (OR) for developing early wheeze related to early maternal smoking was 2.4 [95% confidence interval (CI) 1.6–3.7] in children with a wild‐type CC homozygote genotype of the TNF?857 SNP, while no tobacco‐related risk was seen in children carrying the rare T allele. A clear dose response was observed in children with the CC genotype, with an OR of 1.3 (95% CI 1.1–1.5) per each additional pack per week smoked by the mother during pregnancy. A suggestive interaction with early maternal smoking was also seen for three GSTP1 SNPs (Intron 5, Intron 6 and Ile105Val) with respect to transient wheeze, but not for ADRB2 and wheeze phenotypes. No effect modifications were observed for allergic sensitization. Conclusion Our results suggest that the risk of early childhood wheeze associated with early maternal smoking may be modified by TNF and GSTP1 polymorphisms. Cite this as: S. Panasevich, C. Lindgren, J. Kere, M. Wickman, G. Pershagen, F. Nyberg and E. Melén, Clinical & Experimental Allergy, 2010 (40) 458–467.     

Antibiotic use in early childhood and the development of asthma

BACKGROUND AND OBJECTIVE: Recent investigations have focused on the role of infections in infancy in promoting or protecting against the subsequent development of asthma. A related hypothesis concerns the possible role of medical responses to infections, including the widespread use of antibiotics. We chose children at Rudolf Steiner schools to test this latter hypothesis because a significant proportion of parents rejects the use of conventional treatments, including antibiotics. METHODS: Seventy-five per cent (n = 456) of parents of children aged 5-10 years attending Rudolf Steiner schools throughout New Zealand completed questionnaires which included questions on the use of antibiotics and a history of asthma and wheeze in their children. RESULTS: After controlling for potential confounders, antibiotic use was significantly associated with having a history of asthma (OR = 2.74, 95% CI: 1.10-6.85) or wheeze (OR = 1. 86, 95% CI: 1.06-3.26) but not with current wheeze (OR = 1.08, 95% CI: 0.54-2-16). The adjusted odds ratio for asthma was 4.05 (95% CI: 1.55-10.59) if antibiotics were used in the first year of life and 1. 64 (95% CI: 0.60-4.46) if antibiotics had been used only after the first year of life when compared with children who had never used antibiotics. The number of courses of antibiotics during the first year of life was also associated with increased odds ratios for asthma: 2.27 (95% CI: 1.14-4.51) for one to two courses and 4.02 (95% CI: 1.57-10.31) for three or more courses when compared with no antibiotic use in the first year of life. Although not significant, the association of antibiotics and hay fever (OR = 1.99 [95% CI: 0. 93-4.26]) was of a similar strength to the association of antibiotics with a history of wheeze. Antibiotics were not significantly associated with eczema (OR = 1.23 [95% CI: 0.71-2.13]). CONCLUSION: Antibiotic use in infancy may be associated with an increased risk of developing asthma. Further study is required to determine the reasons for this association.     

Differences in the prevalence of asthma and current wheeze between Jews and Arabs: results from a national survey of schoolchildren in Israel.

BACKGROUND: There is evidence that the prevalence of asthma is higher in Jewish schoolchildren than in Arab schoolchildren. It is not clear to what extent other risk factors explain these differences. OBJECTIVE: To evaluate whether the population group differences in the prevalence of asthma and current wheeze remain after adjustment for several potential risk factors. METHODS: A national survey of 10,057 13- to 14-year-old schoolchildren was carried out in Israel in 1997. There were 7,436 Jewish children and 2,621 Arab children. Differences in the two population groups were examined while controlling for demographic and environmental factors such as: sex, parental education, parental smoking and asthma, crowding, and presence of older siblings. RESULTS: The prevalence of asthma and current wheeze was significantly higher in Jewish children compared with Arab children. The asthma prevalence was 7.8% for Jewish children and 4.9% for Arab children (P = 0.001), and prevalence of current wheeze was 20.7 and 10.1%, respectively (P = 0.001). After adjustment for demographic and environmental factors, the prevalence of asthma and current wheeze was still increased in the Jewish population (odds ratios: 1.51; 95% confidence interval [CI] = 1.06 to 2.15; 2.15 95% CI = 1.70 to 2.73, respectively). History of asthma in parents and residence in a rural area were significant risk factors for asthma and current wheeze. In addition, the presence of less than three older siblings was a significant risk factor for asthma, and female sex, ever having pets, and maternal smoking were significantly associated with current wheeze. CONCLUSIONS: The differences between Jewish and Arab children were not explained by the studied factors. Genetic factors, different environmental exposure, and nutritional habits should be studied to further explain the differences between these populations.     

Risk factors for asthma in children in Lódź region

The incidence of asthma and other allergic diseases continues to increase. In addition to genetic factors, environmental influences are thought to play an important role. The aim of this study was to identify factors that influence and drive the atopic march from atopic sensitization to asthma in children from Lód?. METHODS: 800 atopic children, aged 5-18 years, were included to our study. Parents filled in questionnaires and gave interviews about their children's diseases. 405 (43%) children have diagnosis of asthma. RESULTS: A significant association was observed between asthma and male sex, parents' history of atopy, parental highest school grade, maternal smoking during pregnancy, maternal chronic disease (especially chronic renal diseases), maternal allergen-sensitizing diet during breast-feeding, increased exposure to indoor humidity and moulds. Similar effect was seen for episodes of wheeze occurring in the first 3 years of life as followed: wheezing during an airway infection, wheezing not connected with respiratory tract infection, wheezing not related with physical exercise. Child's daycare attendance (nursery school) was associated with decreased risk of asthma.     

Rhinovirus illnesses during infancy predict subsequent childhood wheezing

BACKGROUND: The contribution of viral respiratory infections during infancy to the development of subsequent wheezing and/or allergic diseases in early childhood is not established. OBJECTIVE: To evaluate these relationships prospectively from birth to 3 years of age in 285 children genetically at high risk for developing allergic respiratory diseases. METHODS: By using nasal lavage, the relationship of timing, severity, and etiology of viral respiratory infections during infancy to wheezing in the 3rd year of life was evaluated. In addition, genetic and environmental factors that could modify risk of infections and wheezing prevalence were analyzed. RESULTS: Risk factors for 3rd year wheezing were passive smoke exposure (odds ratio [OR]=2.1), older siblings (OR=2.5), allergic sensitization to foods at age 1 year (OR=2.0), any moderate to severe respiratory illness without wheezing during infancy (OR=3.6), and at least 1 wheezing illness with respiratory syncytial virus (RSV; OR=3.0), rhinovirus (OR=10) and/or non-rhinovirus/RSV pathogens (OR=3.9) during infancy. When viral etiology was considered, 1st-year wheezing illnesses caused by rhinovirus infection were the strongest predictor of subsequent 3rd year wheezing (OR=6.6; P < .0001). Moreover, 63% of infants who wheezed during rhinovirus seasons continued to wheeze in the 3rd year of life, compared with only 20% of all other infants (OR=6.6; P < .0001). CONCLUSION: In this population of children at increased risk of developing allergies and asthma, the most significant risk factor for the development of preschool childhood wheezing is the occurrence of symptomatic rhinovirus illnesses during infancy that are clinically and prognostically informative based on their seasonal nature.     

Umbilical cord and maternal blood red cell fatty acids and early childhood wheezing and eczema

BACKGROUND: Few studies have explored whether fetal exposure to n-6 and n-3 fatty acids influences the inception of atopic disease. OBJECTIVE: To assess prenatal fatty acid exposures as predictors of early childhood wheezing and eczema. METHODS: In the Avon Longitudinal Study of Parents and Children, late pregnancy maternal blood samples and umbilical cord blood samples were assayed for n-6 and n-3 fatty acids (percentage of total red cell phospholipid), and mothers were asked about wheezing and eczema in their children. We measured associations of 11 n-6 and n-3 fatty acid exposures with wheezing at 30 to 42 months, with wheezing patterns defined by presence (+) or absence (-) of wheezing during 2 periods, 0 to 6 months and 30 to 42 months (transient infant, +/-; later-onset, -/+; persistent, +/+; n=1191 and n=2764 for cord and maternal analyses, respectively), and with eczema at 18 to 30 months (n=1238 and n=2945 for cord and maternal analyses, respectively). RESULTS: In cord blood red cells, the ratio of arachidonic:eicosapentaenoic acid was positively associated with eczema (adjusted odds ratio [OR] per doubling, 1.14; 95% CI, 1.00-1.31; P=.044), the ratio of linoleic acid:alpha-linolenic acid was positively associated with later-onset wheeze (OR, 1.30; CI, 1.04-1.61; P=.019), and the ratio of alpha-linolenic acid:n-3 products was negatively associated with later-onset wheeze (OR, 0.86; CI, 0.75-0.99; P=.040). However, these associations were no longer significant after adjusting for multiple comparisons. CONCLUSIONS: It seems unlikely that fetal exposure to n-6 and n-3 fatty acids is an important determinant of early childhood wheezing and atopic disease.     

Asthma onset and relapse in adult life: the British 1958 birth cohort study.

BACKGROUND: Few studies have investigated adult-onset wheezing because of difficulties identifying childhood asthma or wheeze retrospectively. OBJECTIVE: To investigate risk factors for the incidence and recurrence of wheezing illness in adulthood. METHODS: British children born during 1 week in 1958 (N = 18,558) were followed up periodically. Information on wheezing illness was obtained via parental interviews at ages 7, 11, and 16 years and via cohort member interviews at ages 23, 33, and 42 years. At ages 44 to 45 years a subset (N = 12,069) was targeted for biomedical survey, and total IgE and specific IgE responses to grass, cat, and dust mite were measured. RESULTS: Incidences of wheezing illness at ages 17 to 33 and 34 to 42 years were positively associated with atopy (any specific IgE -0.3 kU/L) and cigarette smoking. For ages 17 to 42 years, proportions of incident "asthma" and incident "wheeze without asthma" associated with atopy, adjusted for sex and smoking, were estimated to be 34% (95% confidence interval [CI], 26%-42%) and 5% (95% CI, 1%-9%), respectively, whereas proportions associated with cigarette smoking, adjusted for sex and atopy, were estimated to be 13% (95% CI, 0%-26%) and 34% (95% CI, 27%-40%), respectively. Among participants with no reported wheezing illness at ages 17 to 23 or 33 years, wheeze prevalence at the age of 42 years was positively associated with symptoms in childhood. CONCLUSIONS: Onset and relapse of wheezing illness in adult life seem to be similarly affected by atopy and cigarette smoking, although the nature of these effects may differ between asthma and wheeze without asthma. Children who apparently "outgrow" early wheezing illness remain at increased risk for relapse or recurrence during midlife.     

Maternal fish intake during pregnancy and atopy and asthma in infancy

BACKGROUND: There is growing evidence that n-3 fatty acids have anti-inflammatory properties and may modulate immune response. Dietary intake of these nutrients during pregnancy could play a role in the risk of asthma and atopy in the offspring. METHODS: Using data from a cohort of women (n=462) enrolled during pregnancy and whose offspring were followed up to 6 years, we evaluated the impact of fish consumption during pregnancy on the incidence of atopy and asthma. Dietary intake was assessed by food frequency questionnaire (42 items) applied by an interviewer. RESULTS: Thirty-four percent of infants had a medical diagnosis of eczema at age 1 year, 14.3% of the children were atopic [based on skin prick test (SPT) at 6 years], and 5.7% had atopic wheeze at age 6 years. After adjusting for potential confounding factors, fish intake during pregnancy was protective against the risk of eczema at age 1 year, a positive SPT for house dust mite at age 6 years and atopic wheeze at age 6 years [odds ratio (OR)=0.73 95% confidence interval (CI) 0.55-0.98, OR=0.68, 95% CI 0.46-1.01 and OR=0.55, 95% CI 0.31-0.96, respectively]. For an increase in fish intake from once per week to 2.5 times per week, the risk of eczema at age 1 year decreased by 37%, and the risk of positive SPT at age 6 years by 35%. Stratification by breastfeeding showed that fish intake was significantly related to a decrease risk in persistent wheeze among non-breastfed children (P for interaction<0.05). No protective effect was observed among breastfed children. CONCLUSION: Our data suggest a protective effect of fish intake during pregnancy on the risk of atopy-related outcomes.     

Does the use of antibiotics in early childhood increase the risk of asthma and allergic disease?

BACKGROUND: One of the mechanisms evoked to explain the increasing prevalences of asthma and allergy, in particular among children, is the 'Western lifestyle' or 'hygiene' hypothesis. As early childhood infections are assumed to hold a protective effect on the development of asthma and allergies, the use of antibiotics at that sensitive age may lead to an increased risk of asthma and allergy. OBJECTIVE: The aim of this study is to investigate the association between the use of antibiotics in the first year of life and the subsequent development of asthma and allergic disorders. METHODS: In a population-based sample of 7-and-8-year-old children questionnaire and skin prick test data were collected from 1206 and 675 subjects, respectively. Prevalence rates of asthma, allergic disorders and skin test positivity were compared between children with and without early life use of antibiotics, taking into account other possible risk factors including early respiratory infections. The effect of genetic predisposition was investigated by stratified analyses of children with and without parental hay fever. RESULTS: The use of antibiotics during the first year of life was significantly associated with asthma (OR = 1.7, 95% CI 1.0-3.1), hay fever (OR = 2.3, 95% CI 1.3-3.8) and eczema (OR = 1.3, 95% CI 1.0-1.8). No significant relationship was found with skin test positivity (OR = 1.1, 95% CI 0.7-1.7). After stratification for the presence of parental hay fever, children without parental hay fever did not show any significant associations between antibiotics use and asthma or allergy, whereas in children with parental hay fever the use of antibiotics was significantly related with asthma (OR = 2.3, 95% CI 1.1-5.1), hay fever (OR = 2.8, 95% CI 1.5-5.1) and eczema (OR = 1.6, 95% CI 1.0-2.6), and of borderline statistical significance with skin test positivity (OR = 1.6, 95% CI 0.9-3.0). CONCLUSION: Early childhood use of antibiotics is associated with an increased risk of developing asthma and allergic disorders in children who are predisposed to atopic immune responses. These findings support recent immunological understanding of the maturation of the immune system.