Parental asthma, parental eczema and asthma and eczema in early childhood

Atopic dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin condition characterized by intense pruritus and a waxing and waning course. AD often presents in infancy and childhood and can persist throughout adulthood. The exact cause of AD is unknown, but it likely reflects an interplay between genetic and environmental factors. AD affects up to 20% of children in the United States, and prevalence may be increasing. Treatment can be effective in alleviating symptoms but serves only to manage the disease, not cure it. Appropriate therapy can also prevent significant complications, such as infection, sleep disturbance, behavioral problems, and growth impairment.

Time trends, ethnicity and risk factors for eczema in New Zealand children: ISAAC Phase Three

BACKGROUND

Eczema is a common chronic disease which has significant morbidity and costs for children and their families. Phase One (1993) of the International Study of Asthma and Allergies in Childhood (ISAAC) found a high prevalence of symptoms of eczema in New Zealand.

OBJECTIVE

In Phase Three (2001-3) we aimed to answer these three questions: Is the prevalence of eczema changing over time?; Are there ethnic differences in prevalence?; and What are the risk factors for eczema?

METHODS

Five New Zealand centres participated in ISAAC Phases One and Three using the same methodology. Questionnaires about ethnicity, symptoms of eczema and environmental factors were completed by parents of 6-7 year olds (children) and self-completed by 13-14 year olds (adolescents). Prevalence and change per year were calculated by centre, ethnicity and gender. Prevalence differences between centres and associations with environmental factors were examined using logistic regression.

RESULTS

There was little change in prevalence over time for the children, and a decrease in prevalence for the adolescents. Prevalence was higher among Māori and even higher among Pacific participants than among European children. Positive associations with current eczema symptoms were found for both age groups for truck traffic in the street of residence, and current paracetamol consumption, and for children only, antibiotics or paracetamol in the 1st year of life. Inverse associations were found with residence in New Zealand less than 5 years, consumption of milk, seafood, and eggs, and presence of a dog in the home.

CONCLUSION

Eczema remains a significant problem, particularly for young Māori and Pacific New Zealanders in whom less recognition of eczema and poorer access to effective, sustained eczema management may be contributing factors. Reverse causation may explain all the environmental findings apart from truck traffic which is increasing in New Zealand.

An indigenous approach to explore health-related experiences among Māori parents: the Pukapuka Hauora asthma study

Background

The prevalence of asthma for Indigenous New Zealand Māori is amongst the highest in the world. Recent evidence shows ethnic differences in asthma symptom prevalence in New Zealand have widened, with asthma symptoms and hospitalisation rates consistently higher for Māori across all age-groups, especially children and adolescents. This paper: outlines our qualitative, longitudinal research exploring the practical issues Māori children and their families face trying to achieve optimum asthma outcomes; details the research methods used within this study; and discusses the process evaluation findings of the features that made this approach successful in engaging and retaining participants in the study.

Methods

Thirty-two Māori families were recruited using a Kaupapa Māori (Māori way) Research approach. Each participated in a series of four in-depth interviews that were carried out at seasonal intervals over the course of one year. Families also took part in an interviewer-administered questionnaire and participated in a Photovoice exercise. All interviews were digitally recorded, transcribed verbatim and independently coded by two researchers. The research team then conducted the analysis and theme development. The questionnaires were analysed separately, with explanations for findings explored within the qualitative data.

Results

The methodology produced a 100 percent retention rate of the participating families over the course of the follow-up. This was attributed to the research collaboration, the respectful research relationships established with families, and the families’ judgement that the methods used enabled them to tell their stories. The acceptability of the methodology will add to the validity and trustworthiness of the findings.

Conclusion

Given the extent and persistence of ethnic disparities in childhood asthma management, it is imperative that an indigenous approach be taken to understanding the core issues facing Māori families. By conducting community-partnership research underpinned by an indigenous methodology, and employing a range of appropriate methods, we have successfully recruited and retained a cohort of Māori families with experiences of childhood asthma. We aim to make their voices heard in order to develop a series of culturally relevant interventions aimed at remediating these disparities.

Risk for asthma in offspring of asthmatic mothers versus fathers: a meta-analysis

BACKGROUND

Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude of the "maternal effect."

METHODOLOGY/PRINCIPAL FINDINGS

We screened the medical literature from 1966 to 2009 and performed a meta-analysis to compare the effect of maternal asthma vs. paternal asthma on offspring asthma susceptibility. Aggregating data from 33 studies, the odds ratio for asthma in children of asthmatic mothers compared with non-asthmatic mothers was significantly increased at 3.04 (95% confidence interval: 2.59-3.56). The corresponding odds ratio for asthma in children of asthmatic fathers was increased at 2.44 (2.14-2.79). When comparing the odds ratios, maternal asthma conferred greater risk of disease than did paternal asthma (3.04 vs. 2.44, p = 0.037). When analyzing the studies in which asthma was diagnosed by a physician the odds ratios were attenuated and no significant differences were observed (2.85 vs. 2.48, N = 18, p = 0.37). Similarly, no significant differences were observed between maternal and paternal odds ratios when analyzing the studies in which the patient population was 5 years or older (3.15 vs. 2.60, p = 0.14). However, in all cases the trend remained the same, that maternal asthma was a greater risk factor for asthma than paternal.

CONCLUSIONS/SIGNIFICANCE

The results show that maternal asthma increases offspring disease risk to a greater extent than paternal disease.

Prevalência e gravidade de sintomas relacionados à asma em escolares e adolescentes no município de Duque de Caxias, Rio de Janeiro

INTRODUÇÃO: A asma é considerada a doença crônica mais comum na infância. Entretanto, há poucos estudos sobre sua prevalência em nosso meio. OBJETIVO: Avaliar prevalência e gravidade de sintomas de asma em escolares e adolescentes de Duque de Caxias (RJ). MÉTODO: Estudo transversal utilizando o questionário do International Study of Asthma and Allergies in Childhood. A amostra foi composta por alunos de 6, 7, 13 e 14 anos. RESULTADOS: Foram avaliados 4.040 alunos de 13 e 14 anos e 2.334 de 6 e 7 anos. A freqüência de sibilos nos últimos doze meses foi de 27,7% entre os mais jovens e de 19% entre os adolescentes (p < 0,0001). No primeiro grupo houve predomínio do sexo masculino (29,9% vs 25,6%, p = 0,01) e no segundo do feminino (21,9% vs 15,8%, p < 0,0001). Não existiram diferenças entre as faixas etárias relacionadas ao diagnóstico prévio de asma (cerca de 10%). Sibilância aos exercícios físicos foi mais prevalente entre os adolescentes (21,4% vs 7,8%, p < 0,0001). A gravidade dos sintomas foi maior entre as adolescentes (asma grave: 6,6% vs 4,4%, p = 0,001), não havendo diferenças entre gêneros aos 6 e 7 anos. CONCLUSÃO: A prevalência de asma em Duque de Caxias é alta, comparável à de outros municípios brasileiros e latino-americanos. Os valores são superiores aos 6 e 7 anos, quando os sintomas predominam no sexo masculino. Entre os adolescentes, a prevalência e a gravidade dos sintomas são maiores no gênero feminino, fato de observação recente e que parece representar novo comportamento epidemiológico da asma.

A case-control study of risk factors for asthma in New Zealand children

OBJECTIVE

As in other English-speaking countries, asthma is a major and increasing health problem in New Zealand. This study examined the risk factors for asthma in children aged 7-9.

METHODS

Cases and controls were randomly selected from participants in the Wellington arm of the International Study of Asthma and Allergies in Childhood (ISAAC). Cases were children with a previous diagnosis of asthma and current medication use (n=233), and controls were children with no history of wheezing and no diagnosis of asthma (n=241).

RESULTS

After controlling for confounders, factors significantly associated with asthma were maternal (OR=3.36, 95% CI 1.88-5.99) and paternal asthma (OR-2.67, 95% CI 1.42-5.02), and male sex (OR=1.81, 95% CI 1.17-2.81). Children from social classes 5 and 6 or with unemployed parents (OR=2.32, 95% CI 1.22-4.44) were significantly more likely to have asthma than children in social classes 1 and 2. There was no significant association between having polio vaccination (OR=2.48, 95% CI 0.83-7.41), hepatitis B vaccination (OR=0.66, 95% CI 0.42-1.04) or measles/mumps/rubella vaccination (OR=1.43, 95% CI 0.85-2.41) and asthma.

CONCLUSIONS

This study has confirmed the associations of family history and lower socio-economic status with current asthma in 7-9 year old children. The role of vaccinations requires further research.

Importance of genetic factors in adolescent asthma: a population-based twin-family study

Gene-environment interactions and inheritance of asthma were studied in 16-yr-old twins and their parents who participated in the nationwide Finnish Twin Cohort Study. Between 1991 and 1994, questionnaires, including a question on physician-diagnosed asthma, were mailed to the members of 2,483 twin families. The individual response rate ranged from 82 to 93%. Information on parental asthma status allowed the genetic modeling of asthma data in two different groups of twins. In families where one of the parents was asthmatic, as much as 87% of the variation in susceptibility to asthma in twins was explained by genetic factors. On the other hand, for twins whose parents were unaffected, a model including environmental effect alone was sufficient to explain the development of asthma. Genetic influences could not be totally excluded, but their role was significantly smaller. These results indicate that the presence of asthma in successive generations is more likely caused by shared genes than shared environmental risk factors; however, substantial heterogeneity among families may exist. Genetic analysis, especially among the families with an obvious familial component in development of asthma, may enhance the chances of revealing the pathogenetic mechanisms

Executive summary

Allergic rhinitis is now recognized as a major cause of morbidity that significantly impairs function and quality of life. Moreover, it is now widely held that the pathophysiologic mechanisms causing nasal allergy contribute, or predispose many individuals, to the development of other airway diseases, including asthma. Allergic rhinitis may well be a factor in 24% of children with otitis media with effusion (OME), and perhaps 28% of cases of chronic sinusitis. As many as 78% of persons with asthma aged 15 to 30 years have elevated serum IgE antibodies to five common aeroallergens. In many instances, nasal allergy signals the presence of more severe disease.

Considerable evidence now suggests that early and appropriate intervention can improve the quality of life and productivity of patients with allergic rhinitis, enhance the academic performance of children, and reduce the prevalence of airway complications. The goal of treatment has shifted from mere symptom alleviation to blocking the pathophysiologic mechanisms that cause chronic allergic inflammation and leave patients vulnerable to airway infections. The earlier in a patient's life that this can be accomplished, the better the anticipated consequences.

A panel of experts was convened in Amsterdam, The Netherlands, on 2 September 1996, to explore these issues and their impact on allergy prevention and treatment in primary care. Their undertaking was supported by an unrestricted educational grant from Schering‐Plough Pharmaceuticals.

Asthma and allergy avoidance knowledge and behavior in postpartum women

OBJECTIVE

Based on family history, infants may be classified as "high risk" or "low risk" for the development of allergy or asthma. Failure to breast-feed and early exposure to cigarette smoke or aeroallergens increase the risk of developing asthma or allergy. Since we suspect that physicians seldom educate mothers on reducing environmental exposures in the postnatal period, we sought to determine the level of maternal knowledge as well as actual avoidance behaviors with respect to these risk factors in high risk and low risk families.

DESIGN

Questionnaire administered by a research assistant.

SETTING

Obstetrics unit of two tertiary care general hospitals.

PATIENTS

A sample of 194 postpartum women with uncomplicated pregnancies, interviewed after 24-hours postpartum.

MAIN OUTCOME MEASURES

(1) Parental history of asthma, allergy or eczema; (2) potential for infant exposure to environmental risk factors for asthma and allergy, as indicated by history of avoidance practices in the home; (3) parental knowledge of risk factors for asthma or allergy; and (4) physician advise on avoidance.

RESULTS

Of 194 women interviewed, a history of doctor-diagnosed asthma, allergy/allergic rhinitis or eczema in either parent was reported by 122 (high risk group). The remaining 72 patients had no history of atopy (low risk group). Of those in the high risk group, 10% of mothers smoked during pregnancy, and about 25% were exposed to second hand smoke on a daily basis. Most of the mothers in the high risk group planned to breast feed (89%). A large number of patients in the high risk group reported potential risk factors for allergy/asthma in their home environments. These included animals in the household (36%), dusty environments (10%) carpeting (47%), cigarette smoke (18%), and others. Despite these risks, only 13% of patients reported being educated by their physicians on improving their home environment. Exposures to environmental risk factors were not different between low and high risk groups. Similarly, knowledge of environmental risk factors and avoidance behaviors were not significantly different between low and high risk groups.

CONCLUSIONS

Many mothers whose infants are at high risk of developing asthma or allergies are not aware of and do not practice avoidance of risk factors. Physicians involved in prenatal care of women with a family history of atopy and asthma should offer advice on reducing exposure to potential risk factors and how to modify their environment in ways that can potentially decrease the risk of asthma or allergy prevalence and severity.

Analysis of familial aggregation of atopic eczema and other atopic diseases by ODDS RATIO regression models

In order to determine the relative importance of genetics and the environment on the occurrence of atopic diseases, we investigated the familial aggregation of atopic eczema, allergic rhinitis, and allergic asthma in the relatives of 426 patients with atopic eczema and 628 subjects with no history of eczema (5,136 family members in total). Analyses were performed by regression models for odds ratios (OR) allowing us to estimate OR for the familial aggregation and simultaneously to adjust for other covariates. Three models were analyzed assuming that the OR i) is the same among any two members of a family, ii) depends on different familial constellations, i.e., whether the pairs are siblings, parents, or parent/sibling pairs, and iii) is not the same between the father and the children and between the mother and the children. The OR of familial aggregation for atopic eczema was 2.16 (95% confidence interval (95%-CI) 1.58-2.96) if no distinction was made between the degree of relationship. Further analyses within the members of the family showed a high OR among siblings (OR = 3.86; 95%-CI 2.10-7.09), while the OR between parents and siblings was only 1.90 (95%-CI 1.31-2.97). Only for atopic eczema was the familial aggregation between fathers and siblings (ms: OR = 2.66; fs: OR = 1.29). This can be explained by stronger maternal heritability, shared physical environment of mother and child, or environmental events that affect the fetus in utero. Since for all atopic diseases a stronger correlation was found between siblings than between siblings and parents, our study indicates that environmental factors, especially during childhood, seem to explain the recently observed increased frequencies of atopic diseases.

Genetic risk for asthma, allergic rhinitis, and atopic dermatitis

In order to explore the genetic risk of a child with a family history of allergies developing asthma, allergic rhinitis, or atopic dermatitis, questionnaires filled in by 6665 families were analysed. The data were collected in a population based cross sectional survey of 9-11 year old schoolchildren living in Munich and southern Bavaria. The relation between asthma, allergic rhinitis, and atopic dermatitis and the number of allergic first degree relatives, and the type of allergic disease was examined. Analyses were done separately for families with single or multiple allergic diseases. In families with one allergic parent the risk of the child developing asthma was increased by asthma in a parent, with an odds ratio (OR) of 2.6 (95% confidence interval 1.7 to 4.0) but not by parental allergic rhinitis with OR 1.0 (0.7 to 1.5) or atopic dermatitis, OR 1.0 (0.6 to 1.6). For allergic rhinitis the highest risk with OR 3.6 (2.9 to 4.6) was observed with allergic rhinitis of one parent, apparently lower for asthma of one parent, OR 2.5 (1.6 to 4.0) or atopic dermatitis, OR 1.7 (1.1 to 2.5). Children with parental atopic dermatitis had a high risk for atopic dermatitis, OR 3.4 (2.6 to 4.4), compared with children with parental asthma, OR 1.5 (1.0 to 2.2), or parental allergic rhinitis, OR 1.4 (1.1 to 1.8). Risk factors in families with combined allergies of two relatives (parents and siblings) were analysed separately for the different combinations. These results support the hypothesis that asthma, allergic rhinitis, and atopic dermatitis are multifactorial diseases brought about by various familial and environmental influences.

Assessment and prediction of asthma and its severity in the pediatric community

Seventy four asthmatic children aged 7 to 11 years were examined along with controls matched by age and sex. Clinical and laboratory investigations preceded a 28-day follow-up where data about morning and evening peak expiratory flow rate (PEF), symptoms and treatment were recorded. The coefficient of variation of PEF was found to be an objective measurement of asthma severity that has statistically significant correlation with both symptoms (rs = .36) and treatment (rs = .60). Moreover, it separates mild and severe asthmatics, as confirmed by statistically significant differences (p = .008 or less) in symptoms, treatment, skin allergy and airways response to exercise. Skin allergy and airways responsiveness to exercise were found to be predictors of both disease and severity. By means of logistic regression analysis it was possible to establish the probabilities for both asthma and severe asthma when children presenting and not presenting these characteristics are compared. One single positive skin test represent a probability of 88% for the development of asthma and a probability of 70% for severe disease. A PEF reduction of 10% after an exercise test implies a probability of 73% for disease and a probability of 64% for severe disease. Increases in these variables imply geometrically increased risks and their presence together have a multiplicative effect in the final risk.

Natural history of allergic diseases in children

Questionnaire data from 1335 14-year-old children with a history of past or present asthma, allergic rhinitis or eczema were analysed regarding age at onset and cessation of symptoms. Incidence of asthma and eczema was highest during the first years of life. Early incidence of asthma was higher in boys than in girls but the sex ratio equalized gradually during childhood. Early incidence of eczema was equal between the sexes but the proportion of girls increased gradually with later age at onset. In 24% of the children more than one symptom was found. Cessation of symptoms was common in asthma (55%), in particular in those with early onset (74%), but less common in eczema (34%). Cessation of symptoms was less common in both diseases when associated with other allergic symptoms. Incidence of allergic rhinitis was fairly constant during childhood and cessation of symptoms was uncommon. A high risk of allergic airways disease was found after early eczema.

Epidemiology of asthma in western Europe

Asthma deaths are uncommon, but have recently increased in some countries due to problems in the management of the disease. Morbidity rates show large variations, which can be attributed to differences in defining the disease, but also to genuine variations, with a trend towards less asthma in northern Europe. It has been suggested that allergic diseases as a whole, and asthma in particular, may exhibit an upward secular trend. Risk factors include a genetic background and environmental triggering factors. The importance of genetic factors is illustrated by family studies and by extreme prevalence rates observed in some communities. Environmental factors include rapid air pollution variations which act as a trigger for asthma attacks. However, at levels currently prevailing in western Europe, air pollutants do not induce a higher incidence of asthma. Altitude generates a gradual decrease in Dermatophagoides, thus explaining both the clinical improvement in asthmatics living in altitude and a lower prevalence of asthma in populations born and living there. Among the other aero-allergens, grass pollens plays a major role in spring, elicitating asthma attacks. Some natural allergens transformed by man (castor bean, soja) can be responsible for asthma epidemics.

Breast feeding and maternal smoking as predictors of wheezing in children age 6 to 10 years

The possibility that controllable environmental factors such as passive smoking and non-breast feeding contribute substantially to wheezing has implications for prevention. Effects of passive smoking and non-breast feeding on wheezing in children aged 6 to 10 years were explored in a historical cohort study of 223 children. Family history of respiratory allergy or asthma, male sex, maternal smoking, and non-breast feeding were significantly associated (p less than 0.05) with wheezing in bivariate analysis. In multivariate loglinear analyses, predictors of wheezing included non-breast feeding (p = 0.05, odds ration = 2.1), male sex (p less than 0.03, odds ratio = 3.1), and family history of respiratory allergy (p less than 0.03, odds ratio = 2.6). In a second model, predictors included an interaction of maternal smoking and family history (p less than 0.005, odds ratio = 4.6) in addition to male sex and family history of respiratory allergy. In further exploration based on tabular analysis, maternal smoking appeared to increase wheezing among children in whom the family history of respiratory allergy was positive (p less than 0.001). Among children in whom the family history of respiratory allergy was negative, non-breast feeding appeared to increase wheezing (p = 0.01). Promotion of breast feeding and reduction of maternal smoking might reduce childhood wheezing.

Demonstration of a common major gene with pleiotropic effects on immunoglobulin E levels and allergy

Atopic disease is generally recognized to be familial, although specific genetic components have yet to be identified. High levels of a unique class of immunoglobulins, immunoglobulin E (IgE), have been shown to be associated with allergies. Several investigators have reported evidence indicating a recessive regulatory locus where an individual with the homozygous recessive genotype has persistently elevated levels of IgE. Willcox and Marsh [1978] have proposed a hypothesis relating IgE production and liability to become allergic. A test of this hypothesis was carried out in the present study. Bivariate segregation analysis of IgE levels and allergy was performed on 173 nuclear families, and the results indicate that an IgE regulatory locus contributes to the familial transmission of allergy. The results are further discussed in the context of the Willcox and Marsh hypothesis.

What is atopy? Sidestepping semantics

Atopy may be viewed as the manifestation of a still-undefined defect. It is characterized by certain clinical findings and frequently by derangements of the immune and autonomic nervous systems. The atopic diseases are a group of seemingly unrelated conditions--eczema, asthma, rhinitis, and perhaps hypertrophic sinusitis, vernal conjunctivitis, and migraine--which cluster in individuals and families. In the respiratory tract and eye, eosinophils in tissues and secretions are characteristic and are not dependent on the presence of immediate hypersensitivity. Symptoms suggestive of mast-cell mediator release are common to all the atopic diseases, and there is some evidence that nonimmunologic mediator release is enhanced in atopic patients. In the most clearly defined atopic diseases, eczema and asthma, approximately 80% of patients have increased IgE responses to normal environmental allergens. Accompanying and perhaps underlying the enhanced IgE responses are deficiencies of T cell numbers and function, particularly in suppressor T lymphocytes. Evidence exists that decreased beta 2-adrenergic function and increased cholinergic and alpha-adrenergic responsiveness accompany and perhaps underlie the atopic diseases, whether allergic or nonallergic.