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.     

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.     

Risk factors for wheezing in early adolescence: a prospective birth cohort study in Brazil.

BACKGROUND: Many asthma studies are available in the literature, but few investigated whether risk factors for asthma differ by sex. OBJECTIVE: To evaluate risk factors for wheezing in early adolescence, with emphasis on sex differences. METHODS: A prospective birth cohort study was initiated in 1993; 87.5% of the original cohort was traced at 11 years, totaling 4,452 adolescents. Current wheezing was defined as at least 1 crisis in the previous 12 months. The following independent variables were analyzed: maternal smoking during pregnancy, wheezing at 4 years, maternal wheezing, and adolescent body mass index. RESULTS: Current wheezing affected 13.5% (95% confidence interval [CI], 12.4%-14.5%) of the cohort. The prevalence of current wheezing was 15.3% (95% CI, 13.7%-16.8%) in boys and 11.7% (95% CI, 10.4%-13.1%) in girls (P < .001). Maternal smoking was related to an increased risk of wheezing for boys but not for girls. There was a significant tracking of wheezing from 4 to 11 years in both sexes, although the magnitude was stronger for boys. A dose-response association between maternal wheezing and adolescent wheezing was observed in boys but not in girls. Finally, obesity was associated with an increased risk of wheezing in boys but not in girls. CONCLUSIONS: The variables explored in this investigation had a stronger effect on adolescent wheezing in boys than in girls. Public health strategies aimed at minimizing the burden of wheezing should take these sex differences into account.     

Maternal sex hormones in early pregnancy and asthma among offspring: a case-control study

BACKGROUND: Sex hormones may be associated with the risk of onset of asthma. OBJECTIVE: To study the association between maternal sex hormone concentrations during early pregnancy and the risk of asthma among offspring. METHODS: A case-control study of 129 asthmatic children and 125 control children 5 to 6 years of age. Maternal sera in early pregnancy were obtained from the Finnish Maternal Cohort serum bank. RESULTS: The means of serum progesterone and estradiol and free estradiol in mothers of asthmatic and control children were 81.0 and 82.8 nmol/L (P =.60), 7.87 nmol/L and 7.65 nmol/L (P =.99), and 149.5 pmol/L and 148.0 pmol/L (P =.95), respectively. There were also no differences in the mean concentrations of maternal sex hormones according to the presence of allergic rhinitis or atopic eczema among the children. CONCLUSIONS: The current results do not support an association between maternal sex hormone concentrations during early pregnancy and onset of allergic disease in early childhood.     

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.     

Maternal vaginal microflora during pregnancy and the risk of asthma hospitalization and use of antiasthma medication in early childhood

BACKGROUND: Infants with wheezing and allergic diseases have a microflora that differs from that of healthy infants. The fetus acquires microorganisms during birth when exposed to the maternal vaginal microflora. It is therefore conceivable that the maternal vaginal microflora might influence the establishment of the infant flora and, as a consequence, the development of wheezing and allergic diseases. OBJECTIVE: We sought to study the associations between the composition of the maternal vaginal microflora and the development of wheezing and asthma in childhood. METHODS: We performed a population-based cohort study in Denmark. Vaginal samples for bacterial analysis were obtained during pregnancy. A total of 2927 women (80% of the invited women) completed the study and had 3003 live infants. Infant wheezing was assessed as one or more hospitalizations for asthma between 0 and 3 years of age. Asthma was assessed as use of 3 or more packages of antiasthma medication between 4 and 5 years of age. RESULTS: Maternal vaginal colonization with Ureaplasma urealyticum during pregnancy was associated with infant wheezing (odds ratio [OR], 2.0; 95% CI, 1.2-3.6), but not with asthma, during the fifth year of life. Maternal colonization with staphylococci (OR, 2.2; 95% CI, 1.4-3.4) and use of antibiotics in pregnancy (OR, 1.7; 95% CI, 1.1-2.6) were associated with asthma during the fifth year of life. CONCLUSION: The composition of the maternal vaginal micro-flora might be associated with wheezing and asthma in the offspring up to 5 years of age.     

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.     

Differential effects of risk factors on infant wheeze and atopic dermatitis emphasize a different etiology

BACKGROUND: Atopic dermatitis (AD) often develops in infancy as the first manifestation of the atopic phenotype. Wheezing is also common in infancy, but it is less clear whether infant wheezing should be considered as an atopic phenotype. If infant wheeze and AD share a common aetiology, this would indicate that infant wheezing is an atopic phenotype. OBJECTIVE: To investigate whether potential risk factors for infant wheeze and AD have similar effects on these 2 phenotypes, indicating a common etiology. METHODS: A total of 34.793 mother-child pairs enrolled in the Danish National Birth Cohort were followed prospectively. Information on wheezing episodes, AD, and prenatal, perinatal, and postnatal risk factors was collected by interview at 12 and 30 weeks of gestation, at 6 and 18 months of age, and by linkage to the Danish Medical Birth Register. Data were analyzed by binary and polytomous logistic regression models. RESULTS: The following variables had significantly differential effects on infant wheezing and AD: parental hay fever, parental asthma, parental AD, sex, maternal age, maternal occupation, smoking during pregnancy, season of birth, birth weight, gestational age, head circumference, breast-feeding, number of older siblings, day care attendance, and pets in the home. CONCLUSION: The majority of risk factors had differential effects on infant wheeze and AD indicative of a different etiology. Infant wheezing does not seem to be etiologically linked to the epidemic of atopic disease, and infant wheezing should not be used as an indicator of the atopic phenotype.     

Maternal allergy acts synergistically with cigarette smoke exposure during pregnancy to induce hepatic fibrosis in adult male offspring

Maternal environmental exposures during pregnancy are known to affect disease onset in adult offspring. For example, maternal asthma exacerbations during pregnancy can worsen adult asthma in the offspring. Cigarette smoking during pregnancy is associated with future onset of cardiovascular disease, obesity and diabetes. However, little is known about the effect of maternal environmental exposures on offspring susceptibility to liver disease. This pilot study examined the long-term effect of maternal allergen challenge and/or cigarette smoking during pregnancy on hepatic inflammation and fibrosis in adult mouse offspring. Ovalbumin (OVA) or phosphate-buffered saline (PBS)-sensitized/challenged CD-1 dams were exposed to mainstream cigarette smoke (MCS) or filtered air from gestational day 4 until parturition. Eight weeks postnatally, offspring were sacrificed for comparison of hepatic histology and mRNA expression. Adult male offspring of OVA-sensitized/challenged dams exposed to MCS (OSM) displayed significantly increased liver fibrosis (9.2% collagen content vs. <4% for all other treatment groups). These mice also had 1.8-fold greater collagen 1A1 mRNA levels. From the results here, we concluded that maternal allergen challenge in combination with cigarette smoke exposure during pregnancy may be an important risk factor for liver disease in adult male offspring.     

Variables affecting asthma course during pregnancy.

BACKGROUND: The course of asthma is frequently altered by pregnancy, but the mechanisms remain undefined. OBJECTIVE: The purpose of this study was to identify specific maternal or pregnancy characteristics that are related to the course of asthma during pregnancy. METHODS: A secondary analysis of a previous prospective study identified 568 pregnant women whose patient-reported asthma course during pregnancy was compared with the women's usual disease course. Potential explanatory variables were compared between groups defined by their pregnancy versus usual course (better, worse, same). RESULTS: Improvement of asthma during pregnancy was noted in 33.6%, worsening was reported in 36.3%, no change was reported in 26.4%, and the course was uncertain in 3.7%. There was a significant concordance between asthma course and course of rhinitis during pregnancy. Rhinitis improved in 51.1% of patients whose asthma improved during pregnancy and worsened in 19.8% of these women. Rhinitis worsened in 55.9% of patients whose asthma worsened during pregnancy and improved in 2.1% of these women. No significant relationships were found between gestational asthma course and maternal demographic factors, panic-fear score, smoking, maternal weight, infant birth weight, or infant sex. CONCLUSIONS: The relationship of gestational asthma course to rhinitis symptoms may have clinical and mechanistic significance. Further studies will be necessary to test this hypothesis.     

Treatment of asthma during pregnancy and perinatal outcomes

PURPOSE OF REVIEW: Asthma is the most common, potentially serious medical problem to complicate pregnancy. Women with asthma have been shown to be at increased risk of complications during pregnancy. Managing asthma during pregnancy is unique because the effect of both the illness and the treatment on the developing fetus as well as the patient must be considered. This review summarizes the recent studies addressing the effects of asthma or asthma medications on perinatal outcomes, including the 2004 Asthma and Pregnancy Working Group of the National Asthma Education and Prevention Program. RECENT FINDINGS: This review summarizes the recent studies addressing the effect of asthma or asthma medications on perinatal outcomes. SUMMARY: The prevalence of asthma in pregnant women appears to be increasing. Recent evidence supports that pregnant women with moderate to severe asthma may have an increased risk of adverse perinatal outcomes. The goal of asthma management during pregnancy is to optimize maternal and fetal health.     

A retrospective study of the relationship between childhood asthma and respiratory infection during gestation

BACKGROUND: Wheeze in children has been found to be associated with prior antepartum haemorrhage and raised levels of IgE in cord blood, and acute wheezing episodes are intimately linked with respiratory viral infections. OBJECTIVE: To assess the relationship between maternal presentation with respiratory tract infections in pregnancy and childhood asthma, taking into account factors which could affect presentation. METHODS: This was a case-control study of 200 asthmatic children, 5-16-year-old, age-matched with one control, having no recorded history of wheeze. Data on respiratory tract infections, maternal wheeze, atopy and smoking was collected from primary care records. Deprivation score was assessed according to small residential areas and subjects were equally distributed between four general practices in Plymouth, UK. RESULTS: Presentation with respiratory tract infections during pregnancy was significantly associated with childhood asthma (OR 1.69, 95% confidence interval 1.05-2.77, P = 0.03). The association was marginally stronger for infections in the first trimester (OR 2.30, 95% CI 1.05-5.41, P = 0.04) and for those with cough during pregnancy (OR 2.24, 95% CI 1.23-4.22, P = 0.007). The associations remained significant after allowing for the effect of the independent variables (gender, maternal smoking, maternal wheeze, allergic rhinitis, eczema, asthma treatment in pregnancy and deprivation [Townsend] score), using multiple logistic regression analysis (ORs and 95% CIs 1.91, 1.14-3.22; 2.32, 1.01-5.34 and 2.29, 1.17-4.48, respectively). There was also an association between numbers of presentations with respiratory infections and childhood asthma (test for trend, P = 0.02). CONCLUSIONS: This study has shown an association between presentation with respiratory infection during gestation and childhood asthma. The results were not affected by the other independent variable factors studied and therefore provide some evidence to support the theory that respiratory viruses may be implicated in the aetiology of asthma.     

Better maternal quality of life in pregnancy yields better offspring respiratory outcomes: A birth cohort

BackgroundIt is suggested that maternal mental health during pregnancy may affect offspring immune and respiratory features, based on the developmental origins of health and disease hypothesis.ObjectiveTo evaluate whether maternal quality of life (QoL) and depression during pregnancy leads to wheezing, asthma, and food allergy of the offspring at 3 years of age.MethodsWe conducted a nationwide, multicenter, prospective birth cohort study, Japan Environment and Children’s Study. All variables were collected from questionnaires. Health-related QoL was measured using the Medical Outcomes Survey Short Form–8 questionnaire with a physical component summary and a mental component summary score. We conducted logistic regression analyses to evaluate the associations of offspring’s wheezing, asthma, and food allergy with maternal QoL and depression.ResultsThere were 72,685 participants with no missing variables. Maternal physical component summary scores of the Medical Outcomes Survey Short Form–8 questionnaire were negatively associated with offspring’s asthma (adjusted odds ratio [aOR], 0.99; 95% confidence interval [CI], 0.99-1.00), current wheezing (aOR, 0.99; 95% CI, 0.99-0.99), and food allergy diagnoses (aOR, 0.99; 95% CI, 0.98-0.99) in children. Offspring’s wheezing and asthma were also associated with maternal depression and anxiety during pregnancy.ConclusionPoor maternal prenatal QoL increased the risk of wheezing, asthma, and food allergy in offspring. In addition, maternal depression and anxiety increased the risk of offspring’s wheezing, asthma, and food allergy.     

Asthma and Pregnancy

Asthma is probably the most common serious medical disorder that may complicate pregnancy. A third of pregnant women with asthma will experience worsening of their symptoms, a third will see improvement of their symptoms and a third will see no change. The primary goal is to maintain optimal control of asthma for maternal health and well-being as well as fetal maturation. Vital patient education should cover the use of controller medication, avoidance of asthma triggers and early treatment of asthma exacerbations. Proper asthma management should ideally be started in the preconception period. Since smoking is probably the most modifiable risk factor of asthma, pregnant woman should avoid active and passive smoking. Acute asthma exacerbation during the first trimester is associated with an increased risk of congenital malformations. Poorly controlled asthma is associated with low birth weight, preeclampsia, and preterm birth. Medications used for asthma control in the non-pregnant population are generally the same in pregnancy with a few exceptions. Inhaled corticosteroids (ICS) are the preferred controller therapy. Budesonide is the preferred ICS. Long-acting B-agonists (LABA) are the preferred add-on therapy to medium to high dose ICS. Major triggers for asthma exacerbations during pregnancy are viral infections and ICS nonadherence.     

Maternal allergy acts synergistically with cigarette smoke exposure during pregnancy to induce hepatic fibrosis in adult male offspring

Maternal environmental exposures during pregnancy are known to affect disease onset in adult offspring. For example, maternal asthma exacerbations during pregnancy can worsen adult asthma in the offspring. Cigarette smoking during pregnancy is associated with future onset of cardiovascular disease, obesity and diabetes. However, little is known about the effect of maternal environmental exposures on offspring susceptibility to liver disease. This pilot study examined the long-term effect of maternal allergen challenge and/or cigarette smoking during pregnancy on hepatic inflammation and fibrosis in adult mouse offspring. Ovalbumin (OVA) or phosphate-buffered saline (PBS)-sensitized/challenged CD-1 dams were exposed to mainstream cigarette smoke (MCS) or filtered air from gestational day 4 until parturition. Eight weeks postnatally, offspring were sacrificed for comparison of hepatic histology and mRNA expression. Adult male offspring of OVA-sensitized/challenged dams exposed to MCS (OSM) displayed significantly increased liver fibrosis (9.2% collagen content vs. <4% for all other treatment groups). These mice also had 1.8-fold greater collagen 1A1 mRNA levels. From the results here, we concluded that maternal allergen challenge in combination with cigarette smoke exposure during pregnancy may be an important risk factor for liver disease in adult male offspring.     

Parental smoking patterns and their association with wheezing in children

OBJECTIVE:

To investigate parental smoking patterns and their association with wheezing in children.

METHODS:

We performed a case-control study that included 105 children between 6 and 23 months of age who were divided into two groups: cases (children with 3 previous episodes of wheezing) and controls (healthy children without wheezing). The children''s exposure to cigarette smoking was estimated using a questionnaire completed by the mothers and by the children''s urinary cotinine levels.

RESULTS:

Based on both the questionnaire results and cotinine levels, exposure to cigarette smoking was higher in the households of cases in which the incidence of maternal smoking was significantly higher than that of paternal smoking. Children in this group were more affected by maternal smoking and by the total number of cigarettes smoked inside the house. Additionally, the questionnaire results indicated that the risk of wheezing was dose dependent. The presence of allergic components, such as atopic dermatitis and siblings with allergic rhinitis and asthma, greatly increased the odds ratio when wheezing was associated with cotinine levels.

CONCLUSION:

Children exposed to tobacco smoke have an increased risk of developing wheezing syndrome. This risk increases in association with the number of cigarettes smoked inside the house and the presence of other allergic components in the family.     

Relations among asthma knowledge,treatment adherence,and outcome

BACKGROUND: Asthma knowledge is frequently assumed to be a prerequisite for optimal asthma treatment. However, the validity of existing asthma knowledge questionnaires has not been rigorously examined, and no contemporary measure of asthma knowledge has received widespread acceptance. OBJECTIVE: To construct and examine the psychometric properties of an asthma knowledge instrument, and its association with demographic and psychosocial variables, asthma medication adherence, and treatment outcome. METHODS: A 25-item Asthma Knowledge Questionnaire was developed with input from national pediatric asthma experts. Parents of 155 children with asthma completed the Asthma Knowledge Questionnaire as well as demographic, family functioning, and home environment measures. Asthma outcomes and adherence with inhaled medication was measured across 12 months. RESULTS: Despite the many steps taken to develop a strong measure of asthma knowledge, reliability was relatively poor. There was also no association between asthma knowledge and treatment adherence or outcomes. Furthermore, asthma knowledge was not a unidimensional construct and was not a simple function of education. CONCLUSIONS: Findings from this study, in combination with previous studies of asthma knowledge questionnaires, suggest that the construction of a simple self-report asthma knowledge instrument for use as a primary outcome measure demonstrating mastery of asthma self-management skills may not be achievable.     

Prenatal exposure to acetaminophen and respiratory symptoms in the first year of life

BACKGROUND: Prevalence of asthma in developed countries increased between the 1970s and the 1990s. One factor that might contribute to the trends in asthma is the increased use of acetaminophen vs aspirin in children and pregnant women. OBJECTIVE: To examine relationships between in utero exposure to acetaminophen and incidence of respiratory symptoms in the first year of life. METHODS: A total of 345 women were recruited in the first trimester of pregnancy and followed up with their children through the first year of life. Use of acetaminophen in pregnancy was determined by questionnaire and related to incidence of respiratory symptoms. RESULTS: Use of acetaminophen in middle to late but not early pregnancy was significantly related to wheezing (odd ratio, 1.8; 95% confidence interval, 1.1-3.0) and to wheezing that disturbed sleep (odds ratio, 2.1; 95% confidence interval, 1.1-3.8) in the first year of life after control for potential confounders. CONCLUSION: This study suggests that use of acetaminophen in middle to late but not early pregnancy may be related to respiratory symptoms in the first year of life. Additional follow-up will examine relationships of maternal and early childhood use of acetaminophen with incidence of asthma at ages 3 to 5 years, when asthma diagnosis is more firmly established.     

Siblings, day-care attendance, and the risk of asthma and wheezing during childhood

BACKGROUND: Young children with older siblings and those who attend day care are at increased risk for infections, which in turn may protect against the development of allergic diseases, including asthma. However, the results of studies examining the relation between exposure to other children and the subsequent development of asthma have been conflicting. METHODS: In a study involving 1035 children followed since birth as part of the Tucson Children's Respiratory Study, we determined the incidence of asthma (defined as at least one episode of asthma diagnosed by a physician when the child was 6 to 13 years old) and the prevalence of frequent wheezing (more than three wheezing episodes during the preceding year) in relation to the number of siblings at home and in relation to attendance at day care during infancy. RESULTS: The presence of one or more older siblings at home protected against the development of asthma (adjusted relative risk for each additional older sibling, 0.8; 95 percent confidence interval, 0.7 to 1.0; P=0.04), as did attendance at day care during the first six months of life (adjusted relative risk, 0.4; 95 percent confidence interval, 0.2 to 1.0; P=0.04). Children with more exposure to other children at home or at day care were more likely to have frequent wheezing at the age of 2 years than children with little or no exposure (adjusted relative risk, 1.4; 95 percent confidence interval, 1.1 to 1.8; P=0.01) but were less likely to have frequent wheezing from the age of 6 (adjusted relative risk, 0.8; 95 percent confidence interval, 0.6 to 1.0; P=0.03) through the age of 13 (adjusted relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.5; P<0.001). CONCLUSIONS: Exposure of young children to older children at home or to other children at day care protects against the development of asthma and frequent wheezing later in childhood.     

Maternal positive skin prick test results and asthma prediction after early childhood wheezing.

BACKGROUND: Previous studies have used parental history of asthma or allergy but not positive skin prick test results to predict the evolution of asthma in wheezing infants. OBJECTIVE: To determine whether positive parental skin prick test results serve as a predictive factor for the subsequent development of asthma in a child with a history of wheezing before the age of 3 years. METHODS: In a retrospective cohort study we investigated 91 individuals from 71 families. Enrollment criteria were age 6 to 40 years, history of wheezing before the age of 3 years, and no chronic lung disease other than asthma. Each participant was asked about current asthma-related symptoms, underwent pulmonary function testing, and underwent skin prick testing. Participants' parents underwent skin prick testing and measurement of total serum IgE levels. RESULTS: Asthma was diagnosed in 56 participants (61%). Although maternal positive skin prick test results conferred a 3.4-fold risk of asthma (P = .02), neither the mother's nor the father's self-reported allergy or asthma was predictive of later development of asthma. CONCLUSION: The presence of parental, and especially maternal, positive skin prick test results is a significant predictive factor for the subsequent development of asthma in early childhood wheezing.