Ethnicity, childhood environment and atopic disorder

Did the choice reform in Stockholm change social disparities in use of outpatient health services for children?

AIM

The aim of this study was to investigate whether the choice reforms in healthcare in Stockholm county in 2008 and 2013 changed the sociodemographic user patterns of outpatient healthcare services for children.

METHODS

The study used regional data on healthcare use linked to sociodemographic data from national registers in the total population of children 0-15 years in the Stockholm county. Change in use of healthcare services was analysed in multiple linear regression in a difference in differences approach of socio-economic indicators.

RESULTS

The choice reform of 2013 increased children's overall use of specialised care by around 30% until 2017 while primary care use decreased by the same degree. The mean number of physician visits in specialised care for children with severe asthma increased from 3.9 to 5.2 per year. Overall, children in families with low maternal education, low disposable income and a non-Western background increased their use of specialised care more than children from families with a more privileged socio-economic situation.

CONCLUSION

There was no indication that the choice reform in Stockholm county increased the social disparities in use of primary and specialised outpatient care for children, rather the opposite.

Allergic diseases attributable to atopy in a population sample of Asian children

The proportion of allergic diseases attributable to atopy remains a subject of controversy. This study aimed to estimate the population risk of physician-diagnosed asthma, rhinitis and eczema attributed to atopy among a population sample of Asian school-age children. Asian children aged 5–18 years (n = 1321) in the Prediction of Allergies in Taiwanese CHildren (PATCH) study were tested for serum allergen-specific immunoglobulin E. Physician-diagnosed asthma, rhinitis and eczema were assessed by a modified International Study of Asthma and Allergies in Childhood questionnaire. Atopy was defined as the presence of serum allergen-specific immunoglobulin E. In this population-based study, 50.4% of the subjects with asthma, 46.3% with rhinitis, and 46.7% with eczema were attributable to atopy. The population attributable risk (PAR) of atopy for three allergic diseases was higher in adolescents (asthma, 54.4%; rhinitis, 59.6%; eczema, 49.5%) than younger children aged less than 10 years (asthma, 46.9%; rhinitis, 39.5%; eczema, 41.9%). Among the seven allergen categories, sensitization to mites had the highest PARs for all three allergic diseases (51.3 to 64.1%), followed by sensitization to foods (asthma, 7.1%; rhinitis, 10.4%; eczema 27.7%). In conclusion, approximately half (46.3 to 50.4%) of Asian children in Taiwan with allergic diseases are attributable to atopy.

A, Alzolibani AA. Filaggrin, major basic protein and leukotriene B4: Biomarkers for adult patients of bronchial asthma, atopic dermatitis and allergic rhinitis

Bronchial asthma (BA), atopic dermatitis (AD), and allergic rhinitis (AR) are well known atopic disorders with complex etiologies. This study was undertaken to investigate the role of filaggrin, eosinophil major basic protein (MBP) and leukotriene B4 (LTB4) in patients with BA, AD, and AR. Sera from 1,246 patients with different atopic disorders and 410 normal healthy controls were collected and were evaluated for filaggrin, MBP and LTB4 by specific sandwich ELISAs, whereas immunoglobulin E (IgE) was used as a positive control for atopic patients. Serum analysis showed that filaggrin levels were remarkably high in patients with AD and in patients with multiple (mixed) atopic disorders (p < 0.001), whereas its levels in BA and AR patients were low but much higher than in normal human sera (p < 0.01). MBP levels were also high in AR, BA and mixed atopic patients, whereas AD patients showed no increase of MBP (p > 0.05). In contrast, LTB4 level was found to be significantly low in all tested atopic patients groups as compared to the levels of LTB4 present in normal human sera (p < 0.001). In conclusion, these findings support an association between filaggrin, MBP or LTB4 and atopic disorders. Our data strongly suggest that filaggrin, MBP or LTB4 might be useful in elucidating the mechanisms involved in the pathogenesis of these atopic disorders.

Examining the association between maternal atopy and birth outcomes using a retrospective cohort in the southeastern region of the USA

OBJECTIVE

To assess birth outcomes in primiparous women with diagnosis of non-asthmatic atopy (NAA). Researchers hypothesised that women with NAA would have reduced the risk of adverse birth outcomes compared with women without NAA. NAA is defined as having allergic rhinitis and/or atopic dermatitis.

SETTING

Women were mostly treated in primary care settings in South Carolina, USA.

PARTICIPANTS

This is a retrospective cohort study in which participants were identified using a Medicaid database. Participants were primiparous women aged 19 to 25. Births occurring between 2004 and 2014 were identified using the South Carolina's Vital Statistics (VS) records of live births. Incomplete records (ie, information on plural birth, gestational age at birth or birth weight missing), plural births or infants born before completing 24 weeks of gestation were excluded. This provided 65 650 complete maternal-infant dyads, representing 97.6% of the maternal records and 96.9% of the VS records. Women previously diagnosed with NAA were frequency matched 1:4 to non-atopic controls for a total of 9965 maternal-infant dyads used in the statistical analysis.

PRIMARY OUTCOME MEASURES

Low birth weight, small for gestational age and preterm birth.

RESULTS

Linear tests for trend were statistically significant (p<0.001), indicating that NAA was associated with improved birth weight and gestational age at birth. After controlling for potential confounders, mothers with NAA had equal risk for each outcome when compared with mothers with no diagnosis of NAA.

CONCLUSION

A diagnosis of NAA among women living in the southeastern region of the USA does not reduce the risk of adverse birth outcomes nor does it elevate the risk of same. Additional studies with more rigorous designs are warranted to confirm the findings in this study.

Role of environmental exposures and filaggrin mutations on associations of ethnic origin with risk of childhood eczema. The Generation R Study

BACKGROUND

The prevalence of childhood eczema varies considerably between ethnic groups. However, data from longitudinal studies remain scarce.

METHODS

We examined the associations of ethnic origin with the development of eczema from birth until the age of 4 years, and whether known environmental and genetic risk factors explain these associations. This study was performed in a multiethnic population-based prospective cohort among 5,082 children. Ethnic origin was based on the parents' country of birth. Data on physician-diagnosed eczema were obtained by annual questionnaires. Information on environmental risk factors was mostly obtained by questionnaires. Filaggrin (FLG) mutations (2282del4, R2447X, R501X, and S3247X) were genotyped for 3,096 children. We used generalized estimating equation models to examine the associations of ethnic origin with the longitudinal odds of eczema at 6 months and 1, 2, 3, and 4 years of age overall and independently.

RESULTS

Compared with Dutch children, Cape Verdean, Dutch Antillean, Surinamese-Creole, and Surinamese-Hindustani children had overall increased risks of eczema (OR (95%-CI): 1.53 (1.15, 2.03), 1.60 (1.21, 2.12), 1.95 (1.56, 2.44), and 2.06 (1.65, 2.57), respectively). Effect estimates for the associations of Cape Verdean and Dutch Antillean origin with eczema became non-significant after adjustment for genetic risk factors or both environmental and genetic risk factors, respectively. Surinamese-Creole and Surinamese-Hindustani children remained to have increased risks of eczema.

CONCLUSIONS

Cape Verdean, Dutch Antillean, Surinamese-Creole, and Surinamese-Hindustani children had increased risks of eczema in the first 4 years of life. Environmental and genetic risk factors partly weakened these associations.

Role of primary and secondary prevention in atopic dermatitis

Atopic dermatitis (AD) is a serious epidemiological problem in industrialized countries. The incidence of AD has increased considerably over the last 30 years. Atopic dermatitis is a chronic, recurrent, inflammatory skin disease accompanied by strong itching. It is characterized by typical features depending on age. The parents of children suffering from AD must be prepared to change their lifestyle. They should avoid factors which can promote skin lesions and apply appropriate, regular skin care. The article describes primary prevention of AD as well as prophylactic measures to avoid skin eczema. It presents the role of infections, vaccinations, breastfeeding and the influence of domestic animals, house renovation and moulds on development of AD. The article also describes the significance of the epidermal barrier, skin colonization by microbial agents, pruritus, stress, food and inhalant allergy among people who suffer from AD.

Mine dumps, wheeze, asthma, and rhinoconjunctivitis among adolescents in South Africa: any association?

The study investigated the association between community proximity to mine dumps, and current wheeze, rhinoconjunctivitis, and asthma among adolescents. This study was conducted during May-November 2012 around five mine dumps in South Africa. Communities in close proximity to mine dumps had an increased likelihood of current wheeze OR 1.38 (95 % CI: 1.10-1.71), rhinoconjunctivitis OR 1.54 (95 % CI: 1.29-1.82), and a protective association with asthma OR 0.29 (95 % CI: 0.23-0.35). Factors associated with health outcomes included other indoor and outdoor pollution sources. Wheeze and rhinoconjunctivitis appear to be a public health problem in these communities. The findings of this study serve as a base for further detailed epidemiological studies for communities in close proximity to the mine dumps e.g. a planned birth cohort study.

Socioeconomic and sociodemographic factors associated with asthma related outcomes in early childhood: the Generation R Study

Rationale

Few studies have analyzed the association of socioeconomic and sociodemographic factors with asthma related outcomes in early childhood, including Fraction of exhaled Nitric Oxide (FeNO) and airway resistance (Rint). We examined the association of socioeconomic and sociodemographic factors with wheezing, asthma, FeNO and Rint at age 6 years. Additionally, the role of potential mediating factors was studied.

Methods

The study included 6717 children participating in The Generation R Study, a prospective population-based cohort study. Data on socioeconomic and sociodemographic factors, wheezing and asthma were obtained by questionnaires. FeNO and Rint were measured at the research center. Statistical analyses were performed using logistic and linear regression models.

Results

At age 6 years, 9% (456/5084) of the children had wheezing symptoms and 7% (328/4953) had asthma. Children from parents with financial difficulties had an increased risk of wheezing (adjusted Odds Ratio (aOR) = 1.63, 95% Confidence Interval (CI):1.18–2.24). Parental low education, paternal unemployment and child's male sex were associated with asthma, independent of other socioeconomic or sociodemographic factors (aOR = 1.63, 95% CI:1.24–2.15, aOR = 1.85, 95% CI:1.11–3.09, aOR = 1.58, 95% CI:1.24–2.01, respectively). No socioeconomic or gender differences in FeNO were found. The risks of wheezing, asthma, FeNO and Rint measurements differed between ethnic groups (p<0.05). Associations between paternal unemployment, child's sex, ethnicity and asthma related outcomes remained largely unexplained.

Conclusions

This study showed differences between the socioeconomic and sociodemographic correlates of wheezing and asthma compared to the correlates of FeNO and Rint at age 6 years. Several socioeconomic and sociodemographic factors were independently associated with wheezing and asthma. Child's ethnicity was the only factor independently associated with FeNO. We encourage further studies on underlying pathways and public health intervention programs, focusing on reducing socioeconomic or sociodemographic inequalities in asthma.

Impact of maternal obesity on inhaled corticosteroid use in childhood: a registry based analysis of first born children and a sibling pair analysis

BACKGROUND

It has been proposed that maternal obesity during pregnancy may increase the risk that the child develops allergic disease and asthma, although the mechanisms underpinning this relationship are currently unclear. We sought to assess if this association may be due to confounding by genetic or environmental risk factors that are common to maternal obesity and childhood asthma, using a sibling pair analysis.

METHODS

The study population comprised a Swedish national cohort of term children born between 1992 and 2008 to native Swedish parents. Maternal body mass index (BMI) was measured at 8-10 weeks gestation. Unconditional logistic regression models were used to determine if maternal obesity was associated with increased risk of inhaled corticosteroid (ICS) in 431,718 first-born children, while adjusting for potential confounders. An age-matched discordant sib-pair analysis was performed, taking into account shared genetic and environmental risk factors.

RESULTS

Maternal over-weight and obesity were associated with increased risk that the child would require ICS (for BMI≥35 kg/m(2), aOR = 1.30, 95%CI = 1.10-1.52 compared with normal weight mothers) in children aged 6-12 years. Similar effects were seen in younger children, but in children aged 13-16 years, maternal obesity (BMI≥30) was related to increased risk of ICS use in girls (aOR = 1.28, 95%CI = 1.07-1.53) but not boys (OR = 1.05, 95%CI = 0.87-1.26). The sib-pair analysis, which included 2,034 sib-pairs older than six years who were discordant for both ICS use and maternal BMI category, failed to find any evidence that increasing maternal weight was related to increased risk of ICS use.

CONCLUSION

Maternal obesity is associated with increased risk of childhood ICS use up to approximately 12 years of age, but only in girls after this age. These effects could not be confirmed in a sib pair analysis, suggesting either limited statistical power, or the effects of maternal BMI may be due to shared genetic or environmental risk factors.

Early respiratory morbidity in a multicultural birth cohort: the Generation R Study

Ethnic disparities in the prevalence of asthma symptoms in children have been described. We evaluated to what extent the association between ethnic background and respiratory symptoms during the first 2 years of life could be explained by the mediating effect of risk factors for respiratory morbidity. The Generation R Study is a multiethnic, population-based birth cohort study. Pre and postnatal risk factors for respiratory morbidity were prospectively assessed by questionnaires. Information about ethnicity was available for 5,684 infants. The associations between ethnic background and lower respiratory symptoms at 12 and 24 months were evaluated with log-binomial regression models. Relative risks and 95 % confidence intervals (RR [95 % CI]) were computed for Cape Verdean, Moroccan, Antillean, Surinamese and Turkish ethnicity with Dutch ethnicity as the reference category. We found an increased risk of lower respiratory symptoms at 24 months in Antillean infants (1.32 [95 % CI 1.12-1.57]) that was mediated by early postnatal exposures (pets keeping, siblings, breastfeeding, daycare attendance, smoke exposure). Turkish infants also had an increased risk of lower respiratory symptoms at 12 and 24 months (1.14 [95 % CI 1.02-1.27] and 1.21 [95 % CI 1.07-1.38], respectively), partly explained by previous morbidity (eczema, infections and upper respiratory symptoms). There were no differences for Cape Verdean, Moroccan or Surinamese, as compared to Dutch infants. Hence, ethnic background was associated with respiratory symptoms during the first 2 years of life and this association was largely explained by mediating effects of known pre and postnatal risk factors for respiratory morbidity.

Preterm birth and inhaled corticosteroid use in 6- to 19-year-olds: a Swedish national cohort study

OBJECTIVE

Preterm birth is associated with respiratory morbidity later in life, including asthma. Previous studies have mainly focused on asthma in early childhood in children born extremely preterm. In this study, we examined the risk of asthma in a national cohort of schoolchildren grouped according to degree of immaturity expressed as completed gestational weeks at birth.

METHODS

This was a register study in a Swedish national cohort of 1 100 826 children 6 to 19 years old. Retrieval of at least 1 prescription of inhaled corticosteroids (ICS) during 2006 was used as the main indicator for asthma. Logistic regression was used to test hypotheses, with adjustment for multiple socioeconomic and perinatal indicators.

RESULTS

Degree of immaturity, expressed as completed gestational weeks at birth, had an inverse dose-response relationship with ICS use. Compared with children born between 39 and 41 weeks' gestation, the odds ratio for ICS use increased with the degree of prematurity, from 1.10 (95% confidence interval: 1.08-1.13) for children born in weeks 37 to 38, to 2.28 (95% confidence interval: 1.96-2.64) for children born in weeks 23 to 28, after adjustment for confounders. The increase in ICS use with decreasing gestational age at delivery was similar in boys and girls, and declined with older age.

CONCLUSION

Preterm birth increased the risk of ICS use in these 6- to 19-year-olds by degree of immaturity, from extremely preterm to early term birth.

The Asthma Insights and Reality in the Maghreb (AIRMAG) study: perspectives and lessons

Asthma is the most frequently encountered allergic respiratory disease, and one that has a potentially serious impact on patients' functioning and well-being. From a public health perspective, it is important to collect data on the prevalence, burden and management of asthma in order to improve understanding of the pathogenesis of asthma and to ensure that national healthcare policies are adapted and appropriate. In this respect, the different AIR surveys, which have collected standardised data on asthma in the general population of a large number of countries around the world, have made an important contribution. The latest of these surveys is the AIRMAG survey, performed in the three Maghreb countries of Algeria, Morocco and Tunisia. In these countries, the prevalence of asthma (3.4% to 3.9%) is in the low to moderate range. This is consistent with rates observed elsewhere in the Mediterranean basin. Nonetheless, the prevalence of asthma in the Maghreb may be expected to rise in the future as populations become more urbanized and adopt a more 'Westernized' lifestyle. Indeed the prevalence of asthma is already higher in the urban coastal regions of these countries than in the more rural mountainous and desert regions. Asthma control in the Maghreb is relatively poor compared to other regions evaluated in previous AIR studies, with control being unacceptable in around three-quarters of respondents. Although part of the explanation may reside in limited access to care, treatment rates for inhaled corticosteroids (26.1% of adults and 29.1% of children) were no worse than those reported in previous AIR studies. On the other hand, asthma monitoring through regular follow-up visits, home flow-meter use and preparation of individualised asthma management plans was in general unsatisfactory. In addition, awareness of asthma in the general population of the Maghreb countries was low. Education measures directed at the patient, together with programmes directed at the physician to ensure systematic monitoring and the use of a 'treat to target' approach to therapy, could do much to increase quality of life and minimise restrictions on activities in patients with asthma in the Maghreb.

Skin sensitivity reactions to some allergens in different population groups of Ethiopian subjects

The prevalence of allergic diseases to a variety of allergens has only been studied in a few countries and it has never been studied in Ethiopia. This study was aimed at assessing the prevalence of skin sensitivity reactions to allergens in Ethiopian subjects. A total of 216 subjects were tested with a skin scratch test using five types of allergens and also for total and differential white blood cell counts. Positive reaction to one or more allergens was detected in 49.5% of the subjects, the most prevalent allergen being mite extract. Some 27% showed a positive reaction to multiple allergens. The mean eosinophil count was higher in the subjects reacting to at least one of the allergens compared to those with no reaction (p=0.038). The results demonstrate a high prevalence of allergic reactions to the few allergens tested. Further studies using several allergens are recommended to substantiate this finding.

Asthma in young south Asian women living in the United Kingdom: the importance of early life

BACKGROUND

Studies of immigrants suggest that the environment during fetal life and duration of residence in the host country might influence the development of asthma. Little is known about the importance of the timing of the exposure in the host country and whether migrants might be especially vulnerable in certain age windows.

OBJECTIVE

We compared the reported prevalence of asthma between young white and south Asian women in the United Kingdom, and investigated associations with country of birth and age at immigration.

METHODS

A questionnaire on atopic disorders was posted to 2380 south Asian and 5796 white young mothers randomly sampled in Leicestershire. Data on ethnicity were also available from maternity records. Data were analysed using multivariable logistic regression and a propensity score approach. Results The reported prevalence of asthma was 10.9% in south Asian and 21.8% in white women. South Asian women who migrated to the United Kingdom aged 5 years or older reported less asthma (6.5%) than those born in the United Kingdom or who migrated before age 5 (16.0%), with an adjusted odds ratio of 0.38 [95% Confidence Interval 0.23-0.64, P<0.001]. For those who migrated aged over 5 years, the prevalence did not alter with the duration of residence in the United Kingdom. Current exposure to common environmental risk factors had relatively little effect on prevalence estimates.

CONCLUSION

These data from a large population-based study support the hypothesis that early life environmental factors influence the risk of adult asthma.

[Allergic diseases. Results from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)]

In the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) from 2003-2006 information was collected on allergic diseases (asthma, atopic dermatitis, hay fever, allergic contact eczema) from a population-based sample of 17,641 0-to 17-year-olds, and blood samples were studied for specific IgE antibodies to 20 common allergens. The lifetime prevalence (LTP) of at least one atopic disease was 22.9 % (95 % CI: 22.0-23.7 %), the 12-month prevalence (12MP) was 16.1 % (15.4-16.8 %); boys (17.3; 16.3-18.2 %) were more frequently affected than girls (14.9; 14.0-15.8 %). Children with a background of migration were less often currently affected by an atopic disease, as were children from families of low social status. According to parents' accounts, the LTP of allergic contact eczema was 9.9 % (9.4-10.5 %); girls (13.8;12.9-14.8) were more frequently affected than boys (6.2; 5.6-6.9 %). Of the 3- to 17-year-olds, 40.8 % (39.6-42.0 %) were sensitised to at least one of the allergens tested; boys (45.0; 43.5-46.5 %) more frequently so than girls (36.4; 35.0-37.9 %). In the states of the former FRG, the LTP of allergic contact eczema was higher (10.2; 9.6-10.9 %) than those in the former GDR (8.4 % 7.4-9.6 %); otherwise there were no East-West differences. The KiGGS data provide the first nationally representative data on allergic diseases and sensitisation. The differences in prevalence observed correspond to a great extent with previous studies and may support the hygiene hypothesis. The prevalences in East and West Germany now seem to have equalised.

Health-related quality of life in children with asthma from different ethnic origins

This study aimed to identify and explain differences in health-related quality of life (QoL) between immigrant and non-immigrant children with asthma. In 274 children (7-17 years of age) generic and asthma-related QoL were assessed. The association between ethnicity and QoL was studied in linear regression model analyses. For the asthma-related QoL, unadjusted analyses showed significant ethnic differences. The non-immigrant children had the highest scores, which implies a better QoL. After adjusting for asthma control and socioeconomic status (SES), ethnic differences disappeared. These results suggest that immigrant children have a similar QoL to that of non-immigrant children from a comparable SES, when their asthma is under control.

Atopic diseases and related risk factors among Dutch adolescents

BACKGROUND

The aim of the present study was to gain insight into the prevalence of asthma, allergic rhinitis, and eczema among Dutch early adolescents, and to study the impact of several social demographic and individual risk factors.

METHODS

Cross-sectional survey study using the self-report questionnaires of the International Study of Asthma and Allergies in Childhood (ISAAC). In January 2003, 10 087 12- to 14-year-old students from 33 secondary schools in four regions of the Netherlands participated in this study.

RESULTS

Of all participants, 52.6% reported that they had an allergic disease at least once in their lifetime. The 12 months prevalence of wheezing, rhinitis, and itchy rash was 12.3%, 28.3%, and 13.5%, respectively. Several social demographic and individual factors (gender, age, education levels, ethnicity, body mass index, and residential area) were significantly associated with the atopic symptoms and diseases.

CONCLUSION

This study showed that allergic conditions are common in the Netherlands. Several social demographic and individual risk factors were related to the atopic diseases and symptoms.

Atopic dermatitis and the 'hygiene hypothesis': too clean to be true?

BACKGROUND

The so-called 'hygiene hypothesis' postulates an inverse relationship between atopic dermatitis (AD) and an environment that leads to increased pathogen exposure.

OBJECTIVES

We sought to systematically identify, summarize and critically appraise: (i) the epidemiological evidence to suggest that environmental exposures that lead to an increase in microbial burden reduce the risk of AD; (ii) whether any specific infections have been shown to reduce AD risk; (iii) whether there is a link between immunizations, use of antibiotics and AD risk; and (iv) to comment on the new therapeutic approaches in AD that have evolved out of the 'hygiene hypothesis'.

METHODS

We searched Medline from 1966 until August 2004 to identify relevant studies for inclusion. Differences in study design and populations did not allow formal meta-analysis. Studies were therefore described qualitatively.

RESULTS

We identified 64 studies that were relevant to our review, 27 (42%) of which were of prospective design. There was prospective evidence to support an inverse relationship between AD and endotoxins, early day care and animal exposure. Two well-designed cohort studies have found a positive association between infections in early life and AD, and measles vaccination and AD. Antibiotic use was consistently associated with an increase in AD risk even into the antenatal period, although a few studies did not reach conventional statistical significance. A few small randomized controlled trials have suggested that probiotics can reduce AD severity and that probiotics may also be able to prevent AD to some degree.

CONCLUSIONS

Although population-based studies have suggested a consistent inverse relationship between AD and increasing family size, this does not seem to be explained by a straightforward increased exposure to a single environmental pathogen. The effect seen with early day care, endotoxin and animal exposure may be due to a nonpathogenic microbial stimulus of a chronic or recurrent nature. This would also explain the risk increase associated with antibiotic use. Caution should prevail in the prescribing of antibiotics early in life, especially in children with a family history of AD. Larger well-designed pragmatic trials on probiotics and the prevention and treatment of AD are now needed to inform whether such interventions should be used in routine clinical practice.

Skin-prick testing as a diagnostic aid for childhood asthma

Diagnosing asthma is problematic when based solely on reported symptoms. The purpose of this study was to evaluate skin-prick testing as a diagnostic aid for asthma in children. Skin-prick testing (SPT) was undertaken in children aged 2-10 years with either no history of wheeze (n = 149) or recent doctor-observed wheeze which responded to treatment with a bronchodilator, the "gold standard" (n = 164). Children with moderate or severe asthma were excluded. SPT positivity increased sharply at age 5 years in wheezers. Data were therefore divided into two age groups: 2- < 5 years (57 controls, 97 wheezers) and 5-10 years (92 controls, 67 wheezers). The sensitivity, specificity, and likelihood ratios of SPT positivity for wheeze were 32%, 89%, and 2.9, respectively, in the younger children, and 82%, 85%, and 5.5, respectively, in the older children. For a prevalence of 30% for asthma, the positive predictive values of a positive SPT were 55% and 70% for the younger and older age groups, respectively. The test characteristics of SPT for helping diagnose asthma in schoolchildren are good. The prevalence of wheeze in preschool children is high, and so SPT should be helpful even in this group. We suggest that clinicians consider skin-prick testing as a diagnostic aid for asthma.

Addressing the prevalence of respiratory allergy in the home environment

Respiratory allergy prevalence has always depended both on genetic predisposition and specific environmental allergenic stimulation that leads to sensitization and eventual symptomatic disease. Changes brought about by modern technology that have afforded a higher quality of life have also accidentally increased the levels of many respirable and ingestible allergens in the environment. In many cases these higher levels of exposure have exceeded individual thresholds, resulting in the phenotypic expression of allergy in many individuals who were previously asymptomatic even though they were genotypically predisposed to developing allergies. Prevalence can be decreased only if susceptible populations are identified as early as possible through careful family history taking and appropriate testing for sensitivity and if exposure to selected allergens is controlled.

Normative data for total serum immunoglobulin E measurements in children of three ethnicities

BACKGROUND

It is about 20 years since IgE measurements were published for children without atopic disease. It is possible that the recent increase in atopic disease is reflected in altered measurements in subjects who have no clinical expression of atopy. If the measurement of IgE is to be used as a marker for atopy to characterize disease categories, contemporary normative data must be available.

OBJECTIVE

To measure total serum IgE in healthy children of three ethnicities born and living in an inner city environment.

METHODS

Subjects were aged 1 to < or = 12 years, of Afro-Caribbean, Bangladeshi and white British ethnicities, with no personal history of current atopic disease. An extra 1 mL of blood for the measurement of total serum IgE was collected when blood was taken for other purposes or when a surgical procedure was being undertaken.

RESULTS

Measurements were taken from 151 boys (median age 5.4 years) and 106 girls (median age 6.0 years), who included 127 Bangladeshis, 58 Afro-Caribbeans and 72 white British children. Measurements increased with age but were not related to gender or ethnicity. The data were significantly higher than previous measurements by sixfold.

CONCLUSION

These contemporary normative data allow the generation of z scores for total IgE measurements for clinical or epidemiological use.

Early respiratory and skin symptoms in relation to ethnic background: the importance of socioeconomic status; the PIAMA study

AIMS

To evaluate ethnic differences in the prevalence of respiratory and skin symptoms in the first two years of life.

METHODS

A total of 4146 children participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Parents completed questionnaires on respiratory and skin symptoms, ethnic background, and other potential confounders during pregnancy, and at 3 months, 1 year, and 2 years of age.

RESULTS

In the first year, "non-Dutch" children (compared with "Dutch" children) had a higher prevalence of runny nose with itchy/watery eyes (11.0% versus 5.0%). In the second year, a higher prevalence of wheeze at least once (26.7% versus 18.5%), night cough without a cold (24.6% versus 15.5%), runny nose without a cold (34.1% versus 21.3%), and runny nose with itchy/watery eyes (13.7% versus 4.6%) was found. Adjustment for various confounders, especially adjustment for socioeconomic factors, reduced most associations between ethnicity and respiratory symptoms. Only runny nose with itchy/watery eyes in the second year of life was independently associated with non-Dutch ethnicity (adjusted odds ratio 2.89, 95% CI 1.3-6.4).

CONCLUSIONS

Non-Dutch children more often had respiratory symptoms in the first two years of life than Dutch children. This could largely be explained by differences in socioeconomic status. Follow up of the cohort will determine whether this higher prevalence of respiratory symptoms in children with non-Dutch ethnicity represents an increased risk of developing allergic disease rather than non-specific or infection related respiratory symptoms.

Current opinion of immunotherapy for ocular allergy

PURPOSE OF REVIEW

Allergic conjunctivitis is common and may be the most prominent or the only feature of allergies. Immunotherapy has been used as a primary treatment for allergies since the early 1900s. Currently the use of immunotherapy for allergic rhinoconjunctivitis is well established and has been shown to decrease the development of bronchial hyperreactivity and asthma. However, the role of immunotherapy for primary treatment of allergic conjunctivitis is unclear. We reviewed the studies where immunotherapy was used with particular attention to the affects on ocular allergies.

RECENT FINDINGS

There are many schedules and methods of delivering immunotherapy. Recent studies have started to assess ocular symptoms as one of the parameters to monitor efficacy of therapy. They follow the affects of immunotherapy on conjunctival provocation tests, ocular symptoms, or the use of eye drops. The literature suggests that using the various immunotherapy modalities at different schedules, ocular symptoms improved even when immunotherapy was used on a rush schedule.

SUMMARY

The initiation of immunotherapy for allergic rhinoconjunctivitis has been shown to switch the immune response to T helper 1 and thus avoid the progression of other atopic conditions. Current literature shows that using many allergens with different forms of immunotherapy appear to have a significant improvement in ocular allergy symptoms and this can be achieved rapidly and safely in most patients. Whether using immunotherapy early in allergic conjunctivitis will alter the progression of other atopic conditions remains to be investigated.

Is early BCG vaccination associated with less atopic disease? An epidemiological study in German preschool children with different ethnic backgrounds

We investigated the association of bacille Calmette-Guérin (BCG) vaccination and atopic manifestations among children. Because many children in the study area were from minority ethnic groups, the effect of ethnicity on disease prevalence was also analyzed. A mandatory health survey included all preschool children from Berlin in 1994. Trained medical personnel asked parents whether their child had ever had a diagnosis of atopic dermatitis (AD), bronchial asthma (BA), and hay fever (HF) or symptoms suggestive of these conditions. BCG-vaccination status was recorded from official vaccination documents. Ethnicity of the child was defined by maternal citizenship. We included 38 808 children in our study (20 813 children from former west Berlin), on average aged 6 years. The proportion of children with a foreign family background was 2.1% in East Berlin and 27.5% in West Berlin. BCG vaccination was more common in East Berlin than in West Berlin (94.2% vs. 16.5%) and in West Berlin more common among children with a foreign family background compared with Germans (25.3% vs. 13.2%). The adjusted odds ratio (95% CI) for BA was 0.85 (0.71-1.00) for BCG-vaccinated individuals. BCG vaccination was not significantly associated with AD or HF. Among non-German children, the odds ratios were 0.35 (0.30-0.42) for AD, 0.58 (0.48-0.70) for BA, and 0.72 (0.54-0.92) for HF. The OR for AD among children living in eastern Berlin was 1.19 (1.04-1.36), no significant regional differences were found for BA or HF. This study demonstrated a weak protective effect of BCG vaccination against asthma but a much stronger protective effect of non-German ethnicity against atopic manifestations among preschool children from Germany.

Cultural adaptation is associated with atopy and wheezing among children of Turkish origin living in Germany

BACKGROUND

Turkish children have been found to suffer less from atopic diseases than their German peers. The underlying causes are unknown.

OBJECTIVE

To evaluate rates of sensitization and atopic disease among children in Germany with German or Turkish ethnicity and different degrees of cultural adaptation.

METHODS

This was a cross-sectional study. The setting was screening for school eligibility in an inner-city district of Berlin/Germany. The participants were preschool children born in Germany with double German or double Turkish parental citizenship. Cultural adaptation of Turkish children was assessed by the language parents used to communicate with their child: only Turkish (n = 60, group A); Turkish and German (n = 269, group B); and only German (n = 103, group C). Group D contained children from German parents (n = 383). The main outcome measures were specific sensitization to common aeroallergens (CAP-System, Pharmacia Phadiatop >or= 0.35 kU/L), and lifetime and 1-year prevalences of allergic disease symptoms (ISAAC questionnaire in German and Turkish, Mantel-Haenszel test for trend).

RESULTS

Sensitization rates for groups A, B, C and D were 8.0%, 6.8%, 18.9% and 18.3%, respectively (P = 0.004). The corresponding prevalence rates for wheeze ever were 6.7%, 9.3%, 12.6% and 21.3% (P < 0.001), wheeze in the past year 3.3%, 3.7%, 9.7% and 10.2% (P = 0.001), itchy rash ever 3.3%, 6.3%, 8.7% and 13.7% (P < 0.001), itchy rash in the past year 1.7%, 3.7%, 4.9% and 9.5% (P < 0.001), respectively. No significant differences were found for hay fever symptoms.

CONCLUSIONS

Higher cultural adaptation is correlated with higher rates of allergic sensitization and disease among children of Turkish origin living in Berlin. This correlation suggests that environmental rather than genetic differences are responsible for the differences observed.

Identification of Tapr (an airway hyperreactivity regulatory locus) and the linked Tim gene family

To simplify the analysis of asthma susceptibility genes located at human chromosome 5q23-35, we examined congenic mice that differed at the homologous chromosomal segment. We identified a Mendelian trait encoded by T cell and Airway Phenotype Regulator (Tapr). Tapr is genetically distinct from known cytokine genes and controls the development of airway hyperreactivity and T cell production of interleukin 4 (IL-4) and IL-13. Positional cloning identified a gene family that encodes T cell membrane proteins (TIMs); major sequence variants of this gene family (Tim) completely cosegregated with Tapr. The human homolog of TIM-1 is the hepatitis A virus (HAV) receptor, which may explain the inverse relationship between HAV infection and the development of atopy.

Allergic and immunologic disorders of the eye. Part II: ocular allergy

Allergy affects more than 15% of the world population, and some studies have shown that up 30% of the US population has some form of allergy. Most of these patients have various target organs for their allergies, and most have ocular involvement. The ocular component may be the most prominent and sometimes disabling feature of their allergy. Some are affected for only a few weeks to months, whereas others have symptoms that last throughout the year. The seasonal forms may present to clinical allergists, whereas the more chronic forms may present to ophthalmologists. Thus, in the second of this 2-part review series (Part I: Ocular Immunology appeared in the November issue of the Journal), an overview is provided of the spectrum of ocular allergy that ranges from acute seasonal allergic conjunctivitis to chronic variants of atopic keratoconjunctivitis. With a better understanding of the immunologic mechanisms, we now can develop better treatment approaches and design further research in intervention of allergic eye diseases.