Environmental associations with eczema in early life

Efficacy and Safety of Fig (Ficus carica L.) Leaf Tea in Adults with Mild Atopic Dermatitis: A Double-Blind, Randomized, Placebo-Controlled Preliminary Trial

Atopic dermatitis (AD) is a chronic, recurrent pruritic skin disease with repeated remissions and exacerbations. Various factors, such as allergies, skin conditions and lifestyle, combine to cause AD, making it difficult to cure completely. Although AD symptoms are suppressed with medications, this is a long-term effort and burden on patients. Thus, safer drugs and alternatives are needed. We previously found that consumption of tea prepared from fig (Ficus carica L.) leaves alleviated allergy and AD symptoms in cultured cells and animals. Therefore, here, we conducted a double-blind, randomized, controlled study in patients with mild AD to evaluate the safety and AD-relieving effects of prolonged consumption of fig leaf tea. Positive effects of fig leaf tea consumption were confirmed in 14 of 15 participants. Eczema Area and Severity Index values were significantly lowered in the fig leaf tea-treated group than in the placebo-treated group. The effect weakened 4 weeks after the end of the intervention, suggesting that continued intake of fig leaf tea was effective. Further assessments confirmed the safety of fig leaf tea consumption and revealed no variations that might pose a health hazard. Therefore, we postulate that fig leaf tea is a natural and safe therapeutic option for AD.

Genetic predisposition and environmental factors associated with the development of atopic dermatitis in infancy: a prospective birth cohort study

The influence of environmental factors on atopic dermatitis (AD) has been investigated in many cross-sectional studies. It remains however unclear if they could influence AD development early in life. This prospective birth cohort study aimed to monitor aspects of family lifestyle and child's nutrition within a Caucasian population and to assess its association with AD development over the first 2 years of life. Genetic predisposition was evaluated based on family history and profilaggrin genotyping. Of 149 included children, 36 developed AD. Infants with a family history of atopy developed AD 2.6 times more frequently (30 of 97) than infants without atopic predisposition (6 of 52). Genotyping was carried out on 50% of the children included. Profilaggrin mutations (R501X, 2282del4, R2447X, and S3247X) were infrequent in our population. Lower incidence of AD was observed in infants exposed to a damp housing environment, lower household income, and smoking mothers with a higher but not with a lower education level.Conclusion: Family history of atopy was a significant risk factor for AD regardless of the most common, currently defined, FLG mutations. Humidity at home and passive smoking seem associated with AD development in infancy. What is Known: • Atopic dermatitis (AD) is associated with mutations in various genes of the immune system and the epidermal barrier complex in particular filaggrin (FLG) mutation. • Inherited factors alone cannot explain the rising AD; environmental factors are therefore likely to play a decisive role in this rise but the exact role that these factors may play in increasing AD risk in infancy remains unclear. Moreover, the relationship between environmental factors and AD has been the focus of mostly cross-sectional studies and not prospective studies. What is New: • This prospective birth cohort study demonstrates that family history of atopy is a significant risk factor for AD regardless of the most common, currently defined, FLG mutations. • A lower incidence of AD was observed in infants exposed to a moist housing environment, lower household income, and smoking of mothers with a higher but not with a lower education level.

How does parental history of atopic disease predict the risk of atopic dermatitis in a child? A systematic review and meta-analysis

BACKGROUND

Parental history of atopic disease is a well-established risk factor for the development of atopic dermatitis (AD), but several aspects of this association remain unclear.

OBJECTIVE

We sought to determine the association of parental history of atopic disease with AD in offspring.

METHODS

We searched PubMed and EMBASE through June 2018 for relevant records and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled odds ratios (ORs) with 95% CI were calculated using random-effects models.

RESULTS

A total of 163 records covering 149 unique studies were included. Of these, 119 studies were included in the meta-analysis. Individuals with parental history of atopic disease had increased odds of AD (OR, 1.81; 95% CI, 1.65-1.99). Parental asthma (OR, 1.56; 95% CI, 1.18-2.05) and allergic rhinitis (OR, 1.68; 95% CI, 1.34-2.11) had a smaller effect than AD (OR, 3.30; 95% CI, 2.46-4.42). The effect of maternal and paternal history was comparable for all atopic diseases. An increase in odds was observed when comparing the effect of having 1 (OR, 1.30; 95% CI, 1.15-1.47) or 2 atopic parents (OR, 2.08; 95% CI, 1.83-2.36), as well as having a parent with 1 (OR, 1.49; 95% CI, 1.28-1.74) or more atopic diseases (OR, 2.32; 95% CI, 1.92-2.81).

CONCLUSIONS

This study provides evidence-based risk estimates that may guide physicians who counsel parents with a history of atopic disease about their children's risk of AD. This information is of particular importance for future efforts toward establishing prophylactic interventions for AD on a general population level.

Infant milk-feeding practices and food allergies, allergic rhinitis, atopic dermatitis, and asthma throughout the life span: a systematic review

BACKGROUND

During the Pregnancy and Birth to 24 Months Project, the USDA and Department of Health and Human Services initiated a review of evidence on diet and health in these populations.

OBJECTIVES

The aim of these systematic reviews was to examine the relation of 1) never versus ever feeding human milk, 2) shorter versus longer durations of any human milk feeding, 3) shorter versus longer durations of exclusive human milk feeding prior to infant formula introduction, 4) feeding a lower versus higher intensity of human milk to mixed-fed infants, and 5) feeding a higher intensity of human milk by bottle versus breast with food allergies, allergic rhinitis, atopic dermatitis, and asthma.

METHODS

The Nutrition Evidence Systematic Review team conducted systematic reviews with external experts. We searched CINAHL, Cochrane, Embase, and PubMed for articles published between January 1980 and March 2016, dual-screened the results according to predetermined criteria, extracted data from and assessed the risk of bias for each included study, qualitatively synthesized the evidence, developed conclusion statements, and graded the strength of the evidence.

RESULTS

The systematic reviews numbered 1-5 above included 44, 35, 1, 0, and 0 articles, respectively. Moderate, mostly observational, evidence suggests that 1) never versus ever being fed human milk is associated with higher risk of childhood asthma, and 2) among children and adolescents who were fed human milk as infants, shorter versus longer durations of any human milk feeding are associated with higher risk of asthma. Limited evidence does not suggest associations between 1) never versus ever being fed human milk and atopic dermatitis in childhood or 2) the duration of any human milk feeding and allergic rhinitis and atopic dermatitis in childhood.

CONCLUSIONS

Moderate evidence suggests that feeding human milk for short durations or not at all is associated with higher childhood asthma risk. Evidence on food allergies, allergic rhinitis, and atopic dermatitis is limited.

Complementary feeding and food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis: a systematic review

BACKGROUND

Nutrition during infancy and toddlerhood may influence health and disease prevention across the life span. Complementary feeding (CF) starts when human milk or infant formula is complemented by other foods and beverages, beginning during infancy and continuing to age 24 mo.

OBJECTIVES

The aim of this study was to describe systematic reviews conducted for the USDA and the Department of Health and Human Services Pregnancy and Birth to 24 Months Project to answer the following question: What is the relationship between the timing of the introduction of complementary foods and beverages (CFBs), or types and amounts of CFBs consumed, and the development of food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis?

METHODS

The literature was searched using 4 databases (CINAHL, Cochrane, Embase, PubMed) to identify articles published from January 1980 to February 2017 that met predetermined inclusion criteria. For each study, data were extracted and risk of bias was assessed. The evidence was qualitatively synthesized to develop a conclusion statement, and the strength of the evidence was graded.

RESULTS

Thirty-one included articles addressed the timing of CFB introduction, and 47 articles addressed the types and amounts of CFBs consumed.

CONCLUSIONS

Moderate evidence suggests that there is no relationship between the age at which CF first begins and the risk of developing food allergy, atopic dermatitis/eczema, or childhood asthma. Limited to strong evidence, depending on the specific food, suggests that introducing allergenic foods in the first year of life (after 4 mo) does not increase the risk of food allergy and atopic dermatitis/eczema but may prevent peanut and egg allergy. There is not enough evidence to determine a relationship between diet diversity or dietary patterns and atopic disease. Research is needed to address gaps and limitations in the evidence on CF and atopic disease, including research that uses valid and reliable diagnostic measures and accounts for key confounders and potential reverse causality.

Short-term effects of weather and air pollution on atopic dermatitis symptoms in children: A panel study in Korea

INTRODUCTION

The effects of weather and air pollution on the severity and persistence of atopic dermatitis (AD) are important issues that have not been investigated in detail. The objective of our study was to determine the short-term effects of meteorological variables and air pollution on AD symptoms in children.

METHODS

We enrolled 177 AD patients with 5 years or younger from the Seoul Metropolitan Area, Korea, and followed for 17 months between August 2013 and December 2014. Symptoms records of 35,158 person-days, including itching, sleep disturbance, erythema, dry skin, oozing, and edema, were obtained. We estimated the effect of meteorological variables including daily mean temperature, relative humidity (RH), diurnal temperature range (DTR), rainfall and air pollutants including particulate matter with an aerodynamic diameter ≤10 μm (PM10), nitrogen dioxide (NO2), and tropospheric ozone (O3) on AD symptoms using a generalized linear mixed model with adjustment for related confounding factors.

RESULTS

A 5°C increase in outdoor temperature and a 5% increase in outdoor RH was associated with 12.8% (95% confidence intervals (CI): 10.5, 15.2) and 3.3% (95% CI: 1.7, 4.7) decrease in AD symptoms, respectively, on the same day. An increase of rainfall by 5 mm increased AD symptoms by 7.3% (95% CI: 3.6, 11.1) for the days with <40 mm rainfall. The risk of AD symptoms increased by 284.9% (95% CI: 67.6, 784.2) according to a 5°C increase in DTR when it was >14°C. An increase in PM10, NO2, and O3 by 10 units increased the risk of AD symptoms on the same day by 3.2% (95% CI: 1.5, 4.9), 5.0% (95% CI: 1.4, 8.8), and 6.1% (95% CI: 3.2, 9.0), respectively.

CONCLUSION

Exposure to meteorological variables and air pollutants are associated with AD symptoms in young children.

Preconceptional and perinatal exposure to traffic-related air pollution and eczema in preschool children

BACKGROUND

Evidence linking prenatal exposure to outdoor air pollution with eczema in early childhood is scare, and the role of components of air pollution and exposure timing remains unclear.

OBJECTIVES

We investigated the association between exposure to air pollution during preconceptional and perinatal period and the risk of eczema in preschool children.

METHODS

We conducted a prospective cohort study of 2598 children aged 3-6 years in Changsha, China. The prevalence of eczema was assessed by a standardized health questionnaire administered by the parents. Individual exposures to nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and particulate matter with an aerodynamic diameter≤10μm (PM₁₀) during the 4th-6th and 1st-3rd month before pregnancy, entire pregnancy, and three trimesters were estimated by an inverse distance weighted (IDW) method based on concentrations measured at monitoring stations. Association between childhood eczema and exposure to air pollution was examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI) for an interquartile range (IQR) increase in exposure.

RESULTS

Life-time prevalence of eczema in preschool children in Changsha was 28.6%. Childhood eczema was associated with traffic-related air pollutant NO₂ during 3 months before pregnancy and entire pregnancy with adjusted ORs=1.19 (95% CI: 1.04-1.37) and 1.21 (95% CI: 1.03-1.42) respectively. The highest risk of eczema was observed for the 1st trimester exposure to NO₂ [OR=1.26 (95% CI: 1.09-1.46)]. However, no association was detected for SO₂ and PM₁₀ exposure during any window. High-level exposure to NO₂ during the whole time period significantly increased the effect of NO₂ in all windows on eczema risk as compared with low-level exposure. Sensitivity analysis indicated that the association between both preconceptional and perinatal exposure to NO₂ and childhood eczema was consistent and robust, and this association was modified by some personal, parental hereditary and indoor environmental factors.

CONCLUSION

Our findings support the hypothesis that early childhood eczema is associated with exposure to traffic-related air pollutant during both preconceptional and perinatal period, especially at a high level of exposure.

Mode of delivery and atopic phenotypes: Old questions new insights? A retrospective study

BACKGROUND

To date studies on the relation between mode of delivery and atopic diseases in are controversial.

OBJECTIVE

The aim of the study was to determine a possible relationship between mode of delivery and risk of atopic phenotypes and, to assess the critical role of some pre-and post-natal parameters as a link between mode of delivery and risk of atopy.

METHODS

1516 children were assessed by skin prick tests, serum total and specific IgE levels. Parental reports on demographic and clinical data were also recorded.

RESULTS

Of the 1516 children enrolled for the study, clinical and laboratory informations were obtained from 917 children. 460 children of them were born via CD and 457 via VD. Mode of delivery did not modify the prevalence of immune sensitization and/or allergic diseases. However, CD was associated with increased risk of atopy (p<0.001). Moreover, some parameters such as familiar history of atopy (p<0.001), habits smoking (p<0.05), exclusive artificial feeding (p<0.001); and breast-feeding time (<3months) (p<0.001) were associated with a major risk of atopy in CD group. Additionally, although our study confirmed that breast-feeding is associated to lower serum total IgE levels than artificial-feeding (p<0.001), it seems that the protective role of breast-feeding is negatively influenced from CD. Also in artificial-feeding subjects CD is related to a significant higher levels of IgE than VD (p<0.001).

CONCLUSIONS

Our findings suggest that CD influences only the risk of atopy but no prevalence of immune sensitization and allergic diseases.

Lower Prevalence of Atopic Dermatitis and Allergic Sensitization among Children and Adolescents with a Two-Sided Migrant Background

In industrialized countries atopic diseases have been reported to be less likely in children and adolescents with a migrant background compared to non-migrants. This paper aimed at both examining and comparing prevalence of asthma, allergic rhinoconjunctivitis and atopic dermatitis and allergic sensitization to specific IgE antibodies in children and adolescents with and without a migrant background. Using data of the population-based German Health Interview and Examination Survey for children and adolescents (KiGGS; n = 17,450; 0–17 years), lifetime and 12-month prevalence of atopic diseases and point prevalence of 20 common allergic sensitizations were investigated among migrants compared to non-migrants. Multiple regression models were used to estimate the association of atopic disease and allergic sensitization with migrant background. In multivariate analyses with substantial adjustment we found atopic dermatitis about one-third less often (OR 0.73, 0.57–0.93) in participants with a two-sided migrant background. Statistically significant associations between allergic sensitizations and a two-sided migrant background remained for birch (OR 0.73, 0.58–0.90), soybean (OR 0.72, 0.54–0.96), peanut (OR 0.69, 0.53–0.90), rice (OR 0.64, 0.48–0.87), potato (OR 0.64, 0.48–0.85), and horse dander (OR 0.58, 0.40–0.85). Environmental factors and living conditions might be responsible for the observed differences.

Lifetime prevalence of childhood eczema and the effect of indoor environmental factors: Analysis in Hispanic and non-Hispanic white children

BACKGROUND

The prevalence of eczema varies markedly across the globe. It is unclear whether the geographic variation is due to race and/or ethnic differences, environmental exposures, or genetic factors.

OBJECTIVE

We investigated the effects of ethnicity and environmental exposures on eczema in Hispanic white and non-Hispanic white children who participated in the Southern California Children's Health Study.

METHODS

We performed a cross-sectional study with sociodemographic predictors and environmental exposures among Hispanic white and non-Hispanic white children ages 4-8 years enrolled in the Children's Health Study, 2002-2003.

RESULTS

Eczema prevalence differed by ethnicity: Hispanic whites showed lower prevalence (13.8%) compared with non-Hispanic whites (20.2%), and adjustment for sociodemographic factors did not account for the ethnic difference (odds ratio [OR] 0.79 [95% confidence interval {CI}, 0.65-0.95]). Parental history of allergic disease had a larger effect in Hispanic whites than in non-Hispanic whites (p for interaction = 0.005). High maternal education level (OR 1.46 [95% CI, 1.14-1.87]), parental history of allergic disease (OR 2.21 [95% CI, 1.78-2.76]), and maternal smoking during pregnancy (OR 1.44 [95% CI, 1.06-1.95]) increased the risk of eczema. Indoor environmental factors (e.g., mold, water damage, humidifier use) increased the risk of eczema in non-Hispanic whites independent of a parental history of allergic disease, but, in Hispanic whites, increased risks were observed, primarily in children without a parental history of allergic disease.

CONCLUSION

Hispanic white children in southern California had a lower prevalence of eczema than non-Hispanic whites, and this ethnic difference was not accounted for by sociodemographic differences. The effects of a parental history of allergic disease and indoor environmental exposures on eczema varied by ethnicity, which indicated that the etiology of eczema may differ in Hispanic whites and in non-Hispanic whites.

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.

Effect of lipid peroxidation, antioxidants, macro minerals and trace elements on eczema

The exact etiology and pathogenesis of eczema are not yet fully understood, although different factors are considered as pathogenic mechanisms in the development of eczema. Our study was designed to determine extent of serum lipid peroxidation, antioxidants, macro minerals and trace elements in patients with eczema, and thereby, find any pathophysiological correlation. The study was conducted as a case-control study with 65 eczema patients as cases and 65 normal healthy individuals as controls. Lipid peroxidation was assessed by measuring the serum level of malondialdehyde (MDA). Antioxidants- vitamin A and E concentration was determined by RP-HPLC method whereas vitamin C was evaluated for serum ascorbic acid by UV spectrophotometric method. Serum macro minerals (Na, K, Ca) and trace elements (Zn, Fe) were determined by Atomic Absorption Spectroscopy (AAS). This study found significantly higher level of MDA (p < 0.001) and lower level of antioxidants (p < 0.05) in patients in comparison to the control subjects. Analysis of serum macro minerals (Na, K and Ca) and trace elements (Zn, Fe) found that the mean values of Na, K, Ca, Zn and Fe were 2771.60 ± 75.64, 66.33 ± 3.03, 48.41 ± 2.50, 0.30 ± 0.02 and 0.29 ± 0.009 mg/L for the patient group and 3284.81 ± 34.51, 162.18 ± 3.72, 87.66 ± 2.10, 0.75 ± 0.06 and 0.87 ± 0.06 mg/L for the control group, accordingly. There was a significant difference for all the minerals between the patients and controls (p < 0.001). This study suggests a strong association between the pathogenesis of eczema with the elevated level of MDA and depleted level of antioxidants, macro minerals, and trace elements.

Atopic dermatitis is a serious health problem in Poland. Epidemiology studies based on the ECAP study

Introduction

Global epidemiological studies have revealed considerable geographical differences in prevalence of atopic dermatitis (AD).

Aim

To present the epidemiology of AD, risk factors and co-occurrence of allergic diseases in the Polish population.

Material and methods

The present paper is a part of the Epidemiology of Allergic Disorders in Poland study. We studied 22 703 participants by ECRHS/ISAAC questionnaire; 18 617 (53.8% female, 24.2% 6–7 y.o., 25.4% 13–14 y.o., 50.4% 20–44 y.o.) completed questionnaires were accepted. Four thousand seven hundred and eighty-three participants (25.7%) have undergone a medical examination.

Results

Atopic dermatitis was diagnosed in 3.91% (6–7 y.o. 5.34%, 13–14 y.o. 4.3%, adults 3.02%), more often in females (OR = 1.52; 95% CI: 0.56–0.77), in the cities (OR = 2.23; 95% CI: 1.61–3.09), in mothers (OR = 2.07; 95% CI: 1.72–2.48) and fathers (OR = 2.00; 95% CI: 1.61–2.49) with atopy, higher education (OR = 1.61; 95% CI: 1.11–2.32) and economic status (OR = 1.35; 95% CI: 1.04–1.74). The highest prevalence was found in Katowice (4.89%) and lowest in rural areas (1.9%). Coexisting AD and allergic rhinitis (AR) was found in 26.17%, AR and asthma in 9.09% and AD, AR and asthma in 14.6%. Atopic dermatitis was diagnosed by allergologists in 6.5% (6–7 y.o. 8.7%, 13–14 y.o. 9.0%, adults 3.6%). Most diagnoses were made in Poznan (16.76%) and smallest in rural area (3.67%). 78.8% of subjects were diagnosed with AD for the first time although they had earlier experienced its symptoms.

Conclusions

Atopic dermatitis prevalence in Poland is below the mean rate for Europe, but the risk factor profile is similar to other countries. Atopic dermatitis is more frequent in well-educated females with atopic parents and high socioeconomic status and who live in a city.

A systematic review of socioeconomic position in relation to asthma and allergic diseases

The role of socioeconomic position (SEP) in the development of asthma and allergies is unclear, with some pointing to the risks of low SEP and other research pointing in the direction of higher SEP being associated with higher prevalence rates. The aim of this systematic review is to clarify associations between SEP and the prevalence of asthma and allergies. Out of 4407 records identified, 183 were included in the analysis. Low SEP was associated with a higher prevalence of asthma in 63% of the studies. Research on allergies, however, showed a positive association between higher SEP and illness in 66% of studies. Pooled estimates for the odds ratio of disease for the highest compared with the lowest SEP confirmed these results for asthma (unadjusted OR 1.38, 95% CI 1.37-1.39), allergies in general (OR 0.67, 95% CI 0.62-0.72), atopic dermatitis (unadjusted OR 0.72, 95% CI 0.61-0.83) and allergic rhinoconjunctivitis (unadjusted OR 0.52, 95% CI 0.46-0.59). Sensitivity analyses with a subsample of high-quality studies led to the same conclusion. Evidence from this systematic review suggests that asthma is associated with lower SEP, whereas the prevalence of allergies is associated with higher SEP.

Effects of probiotics for the treatment of atopic dermatitis: a meta-analysis of randomized controlled trials

BACKGROUND

The effects of probiotics on the treatment of atopic dermatitis (AD) are inconclusive.

OBJECTIVE

To determine the clinical effect of probiotics in the management of AD overall and in different age groups.

METHODS

A comprehensive search of databases through December 2013 was performed. For this meta-analysis, randomized controlled trials measuring the treatment effects of probiotics or synbiotics in patients diagnosed with AD were included. The primary outcome was a difference in Scoring of Atopic Dermatitis (SCORAD) values between the treatment and placebo groups overall and in different age populations.

RESULTS

Twenty-five randomized controlled trials (n = 1,599) were available for this meta-analysis. Significant differences in SCORAD values favoring probiotics over the control were observed overall (mean -4.51, 95% confidence interval -6.78 to -2.24), in children 1 to 18 years old (-5.74, 95% confidence interval -7.27 to -4.20), and in adults (-8.26, 95% confidence interval -13.28 to -3.25). However, the effectiveness of probiotics in infants (<1 year old) with AD was not proved. The effect of synbiotic use was not significantly different from that of probiotic use. Treatment with a mixture of different bacterial species or of Lactobacillus species showed greater benefit than did treatment with Bifidobacterium species alone.

CONCLUSION

The overall result of this meta-analysis suggests that probiotics could be an option for the treatment of AD, especially for moderate to severe AD in children and adults. However, no evidence was found supporting the beneficial role of probiotics in infants.

Does early feeding promote development of oral tolerance?

The prevalence of food allergy has continued to rise over the last 10-15 years, with building concern over the underlying causes and the best strategies to reverse this. Although it is still not clear if infant feeding practices play any significant role in either the aetiology of this epidemic or in its prevention, these have nonetheless been core to many previous prevention strategies. Early 'allergen avoidance' strategies have not only failed, but have instead been increasingly associated with increased risk of allergic disease. Together with other observations in humans and animals, this suggests that earlier introduction of allergenic foods may be a more logical preventive strategy. Based on this, there are several randomised controlled trials world-wide assessing the merits of early introduction of complementary feeding and/or allergenic foods. Until the results of these studies are available it is difficult to provide definitive recommendations regarding the role of early feeding in the induction of oral tolerance and prevention of food allergy.

Alcohol intake in pregnancy increases the child's risk of atopic dermatitis. the COPSAC prospective birth cohort study of a high risk population

BACKGROUND

Atopic dermatitis has increased four-fold over the recent decades in developed countries, indicating that changes in environmental factors associated with lifestyle may play an important role in this epidemic. It has been proposed that alcohol consumption may be one contributing risk factor in this development.

OBJECTIVE

To analyze the impact of alcohol intake during pregnancy on the development of atopic dermatitis during the first 7 years of life.

METHOD

The COPSAC cohort is a prospective, longitudinal, birth cohort study of 411 children born to mothers with a history of asthma, followed up for 7 years with scheduled visits every 6 months as well as visits for acute exacerbations of atopic dermatitis. Risk of atopic dermatitis from any alcohol consumption during pregnancy was analyzed as time-to-diagnosis and adjusted for known risk factors.

RESULTS

177 of 411 children developed atopic dermatitis before age 7 years. We found a significant effect of alcohol intake during pregnancy on atopic dermatitis development (HR 1.44, 95% CI 1.05-1.99 p=0.024). This conclusion was unaffected after adjustment for smoking, mother's education and mother's atopic dermatitis.

LIMITATIONS

The selection of a high-risk cohort, with all mothers suffering from asthma, and all children having a gestational age above 35 weeks with no congenital abnormality, systemic illness, or history of mechanical ventilation or lower airway infection.

CONCLUSION

Alcohol intake by pregnant women with a history of asthma, is significantly associated with an increased risk for the child for developing atopic dermatitis during the first 7 years of life.

Prevalence of atopic dermatitis in Korea: analysis by using national statistics

We attempted to investigate the prevalence of atopic dermatitis (AD) in Korea by using national statistics. Data on AD patients who received medical service at least once a year from 2003 through 2008 were collected from health insurance research team of National Health Insurance Corporation. Data of estimated populations during the same period were obtained from the Statistics Korea. In 2008, the prevalence of AD was 26.5% in aged 12-23 months and decreased substantially to 7.6% at age 6 yr, 3.4% at age 12 yr and to 2.4% at age 18 yr. In males, the prevalence was higher than females until 2 yr of age, while the opposite was shown in children aged 2 yr or older. In children aged less than 24 months, the prevalence of AD has increased from 19.8% to 23.8% between the years 2003 and 2008, while the prevalence showed no increase in the older age group. In conclusion, the prevalence of AD in 2008 peaked during infancy up to 26.5% and decreased thereafter. Our findings also suggest that increasing prevalence of AD in children less than 24 months might be responsible for the recent increase in the prevalence of AD in Korean children.

Point and period prevalences of eczema in rural and urban schoolchildren in Ghana, Gabon and Rwanda

BACKGROUND

Eczema is a growing problem in Africa, particularly amongst children.

OBJECTIVES

To investigate the point-prevalences of eczema by physical examination in schoolchildren living in rural and urban areas and with different socioeconomic backgrounds in Ghana, Gabon and Rwanda. In Ghana period-prevalences were also estimated by questionnaire and compared with the point-prevalences.

METHODS

In total, 4839 schoolchildren in Ghana, Gabon and Rwanda were seen by at least one dermatologist. The point-prevalences of eczema were estimated on the basis of physical examination. Period-prevalences were measured in Ghana with questionnaire based-interviews adapted from the International Study of Asthma and Allergies in Childhood (ISAAC).

RESULTS

The point-prevalences were 1.5% and 1.6% in the two Ghanaian studies; 4% in Gabon and 0.8% in Rwanda. The period-prevalences were 2.6% and 4.4% in the two Ghanaian studies. The prevalences of eczema were not significantly different when comparing the urban and rural groups as well as the different socioeconomic levels. The sensitivity and positive predictive value to identify eczema cases based on the questionnaires compared to the diagnoses by physical examination were only 33% and 22% in the first Ghanaian study and 10% and 4% in the second Ghanaian study respectively.

CONCLUSIONS

The point-prevalences of eczema in the three African countries studied were low compared with industrialized countries. Physical examination by a dermatologist is still the gold standard to identify eczema cases because the sensitivity and the positive predictive value to identify eczema cases with questionnaires were low in the two Ghanaian studies.

Allergic characteristics of urban schoolchildren with atopic eczema in Ghana

BACKGROUND

Atopic eczema is an increasing clinical problem in Africa.

OBJECTIVE

To determine allergic characteristics and to identify possible risk factors for eczema among schoolchildren in an urbanized area in Ghana.

PATIENTS AND METHODS

Schoolchildren aged 3-16 years with eczema were recruited. For each patient, one to three age- and sex-matched controls were selected. All children completed a questionnaire and were skin prick tested with a panel of allergens. Blood was drawn to determine the total and allergen-specific IgE. Conditional logistic regression models with the matching factors included in the model were used to calculate the odds ratios and to adjust for possible confounders.

RESULTS

A total of 52 children with eczema (27 boys and 25 girls) and 99 controls were included. Levels of total IgE were found to be 9.1 (1.1; 78.4) times more often elevated in children with eczema. This association was mainly driven by elevated IgE levels against cockroach antigen. Children with eczema were found to have 2.0 (0.87; 4.7) times more often positive skin prick tests (SPT), but this association diminished to 1.2 (0.40; 3.6) after adjustment for total IgE levels. Frequent washing with soap was identified as a risk factor for the development of eczema among these children.

CONCLUSION

Schoolchildren with eczema in Ghana were characterized by elevated IgE levels especially against cockroach antigen. The association between eczema and positive SPT was much weaker suggesting immune hyporesponsiveness of the skin. After adjustment for IgE level, SPT were less suitable to distinguish children with and without eczema.

The prevalence of atopic dermatitis in children is influenced by their parents' education: results of two cross-sectional studies conducted in Upper Austria

Atopic dermatitis (AD) is an important health problem worldwide. Several studies have shown that a positive family history is a strong risk factor. We studied the prevalence of AD among 23,583 Austrian school children and examined the association between the prevalence of AD in children and their parents' education at two points in time. As part of the International Study of Asthma and Allergy in Childhood programme, two cross-sectional studies were conducted in Upper Austria (Federal State of Austria) between the years 1995-97 (Phase I) and 2001-03 (Phase III). All pupils of pre-school classes and of first and second grade of all elementary schools in seven districts of Upper Austria received standardized questionnaires, resulting in a total of 13,399 (Phase I) and 13,731 (Phase III) children. All variables examined concerning AD showed an increase in prevalence in the age group examined: During the first study, 9.6% of the children ever had eczema diagnosed by a doctor (Phase III: 13.3%), whereas 9.2% ever had symptoms of AD (Phase III: 11.0%). In Phase I, 6.0% of the children had an itchy rash in the past 12 months (Phase III: 6.7%). In both studies, high parental education (i.e. high school or university degree) was an independent statistically significant risk factor for eczema in the child, resulting in an adjusted Odds Ratio between 1.13 and 1.37. In a census-like-survey, we are able to demonstrate a statistically significant association between parental education and the prevalence of AD in their children, which is independent of a possible parental AD.

The prevalence, characteristics of and risk factors for eczema in Belgian schoolchildren

Childhood eczema is common in infants, but its nature and extent during later childhood remains unclear. In this cross-sectional study we examined the prevalence and characteristics of eczema in an unbiased community population of 2,021 Belgian schoolchildren, aged 3.4 to 14.8 years with skin prick testing and parental questionnaires. Our study identified an eczema prevalence of 23.3% and a considerable allergic comorbidity, mainly in sensitized children. The reported prevalence of eczema in infancy was 18.5% and for current eczema 11.6%. The overall sensitization rate (33.2%) as well as sensitization rates for the individual allergens were significantly higher in children with "eczema ever." Sensitization to Dermatophagoides pteronyssinus (19.6%), mixed grass pollen (15.1%), and cat (9.1%) were most common. Until the age of 6 years, boys with eczema were significantly more sensitized than girls (p = 0.007). Children with both eczema in infancy and current eczema show a tendency to be more sensitized than children with eczema in infancy only or current eczema only, but significance was only noted for a few individual allergens. Analysis of factors associated with eczema revealed a predominantly atopic profile characterized by family or personal history of allergy. Breastfeeding and environmental factors seemed to assume little relevance except for a protective effect of prematurity and having a dog at birth.

Cellular and molecular mechanisms in atopic dermatitis

Atopic dermatitis (AD) is a pruritic inflammatory skin disease associated with a personal or family history of allergy. The prevalence of AD is on the rise and estimated at approximately 17% in the USA. The fundamental lesion in AD is a defective skin barrier that results in dry itchy skin, and is aggravated by mechanical injury inflicted by scratching. This allows entry of antigens via the skin and creates a milieu that shapes the immune response to these antigens. This review discusses recent advances in our understanding of the abnormal skin barrier in AD, namely abnormalities in epidermal structural proteins, such as filaggrin, mutated in approximately 15% of patients with AD, epidermal lipids, and epidermal proteases and protease inhibitors. The review also dissects, based on information from mouse models of AD, the contributions of the innate and adaptive immune system to the pathogenesis of AD, including the effect of mechanical skin injury on the polarization of skin dendritic cells, mediated by keratinocyte-derived cytokines such as thymic stromal lymphopoietin (TSLP), IL-6, and IL-1, that results in a Th2-dominated immune response with a Th17 component in acute AD skin lesions and the progressive conversion to a Th1-dominated response in chronic AD skin lesions. Finally, we discuss the mechanisms of susceptibility of AD skin lesions to microbial infections and the role of microbial products in exacerbating skin inflammation in AD. Based on this information, we discuss current and future therapy of this common disease.

First evidence of a possible association between gastric acid suppression during pregnancy and childhood asthma: a population-based register study

BACKGROUND

Recent data in mice suggest that acid suppression during pregnancy yields offspring with type 2 T helper-dominant immunity, suggesting a predisposition for allergy.

OBJECTIVE

To determine the association of in utero exposure to acid-suppressive medications and the subsequent development of allergic diseases in children.

METHODS

We studied a population-based observational cohort formed by linking data from three Swedish national healthcare registers: the Medical Birth Register, the Hospital Discharge Register, and the Swedish Prescribed Drug Register. Main outcome measures included a hospital discharge diagnosis of an allergic disease or prescription for asthma medications, epinephrine auto-injectors, antihistamines or steroid ointments in children. Data were analysed using the Mantel-Haenszel procedure.

RESULTS

Twenty-nine thousand four hundred and ninety (5.03%) children had a discharge diagnosis of allergy or prescriptions for allergy medications. Five thousand six hundred and forty-five (0.96%) children had been exposed to acid suppression therapy during pregnancy; of these, 405 (0.07%) were treated for allergic diseases. Exposure to acid-suppressive medications in utero was associated with an increased odds ratio (OR) for developing allergy (OR 1.43, 95% confidence interval (95% CI) 1.29-1.59). We observed this association irrespective of the type of drug, time of exposure during pregnancy, and maternal history of allergy. The use of maternal acid-suppressive medication was associated with an increased OR for the development of childhood asthma (3.7% in the population at large vs. 5.6% in exposed children, OR 1.51, 95% CI 1.35-1.69), but not for other allergic diseases.

CONCLUSION

These data provide first evidence of a significant association between in utero exposure to acid-suppressive drugs and the risk of developing childhood asthma.

Atopic dermatitis and risk factors in poor children from Great Buenos Aires, Argentina

BACKGROUND

In recent decades, the prevalence of atopic dermatitis (AD) has risen steadily, and risk factors for AD are currently being investigated worldwide. In Argentina, there are no available data on risk factors of AD.

AIM

To determine the prevalence of and any gender predilection for AD, and to identify familial and environmental factors that are associated with increased AD risk.

METHODS

In this case-control cross sectional study, 603 children aged 12-60 months old from a poor urban community in Buenos Aires were recruited. AD was defined following UK Working Party Diagnostic Criteria. We evaluated the relationship between AD and the presence of family history of atopy, > 5 family members, wearing synthetic clothes, having a carpeted room, eating > or = 3 eggs/week, tobacco smoking indoors by family members, and living< 300 m from a main road, polluted stream or industry.

RESULTS

The prevalence of AD was 41.1% (95% CI 37.2-45.2%). Logistic regression analysis showed that AD was significantly associated only with a family history of atopy (OR = 5.7; 95% CI 3.7-8.8%; P = 0.0000), wearing synthetic clothes (OR = 2.2; 95% CI 1.4-3.5; P = 0.0009), having a carpeted room OR = 1.9; 95% CI 1.2-3.0%; P = 0.009) and living < 300 m from an industry (OR = 1.93; 95% CI 1.2-3.1%; P = 0.0051).

CONCLUSION

We found a high prevalence of AD in our study population. Not all the investigated risk factors for AD had a significant association with the disease.

Inhibition of skin inflammation and atopic dermatitis by topical application of a novel ceramide derivative, K112PC-5, in mice

PC-9S (N-Ethanol-2-mirystyl-3-oxo-stearamide) is a synthetic ceramide and has been known to be effective in atopic and psoriatic patients. K112PC-5 (2-Acetyl-N-(1,3-dihydroxyisopropyl)-tetradecanamide) is a novel ceramide derivative of PC-9S. In the present study, we examined the effect of K112PC-5 on macrophage and T lymphocyte function in primary macrophages and splenocytes, respectively, as well as the effect of topical application of K112PC-5 on skin inflammation and atopic dermatitis (AD) in mouse models. K112PC-5 inhibited lipopolysaccharide-induced nitrite generation in mouse peritoneal macrophages in a dose-dependent manner. However, K112PC-5 did not affect concanavalin A-induced proliferation, interleukin (IL)-2 secretion and IL-4 secretion in mouse splenocytes. In addition, K112PC-5 significantly suppressed the increase in phorbol ester-induced ear thickness in BALB/c mice. Further study demonstrated that topical application of K112PC-5 also inhibited AD induced by extracts of dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae, in NC/Nga mice. Taken together, these results showed that K112PC-5 exerted an anti-inflammatory effect both in vitro and in vivo and proved to be beneficial in an animal model of AD. Our results suggest that K112PC-5 might be beneficial as a topical agent for the treatment of AD.

Inhibition of atopic dermatitis-like skin lesions by topical application of a novel ceramide derivative, K6PC-9p, in NC/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that commonly begins in childhood. K6PC-9p (N-(Ethyl dihydrogenphosphate)-2-hexyl-3-oxo-decanamide) is a synthetic ceramide derivative of PC-9S (N-Ethanol-2-mirystyl-3-oxo-staramide), which was known to be effective in atopic patients. In this study, we examined the effect of topical application of K6PC-9p on skin inflammation and AD-like skin lesions in mouse models. K6PC-9p dose-dependently inhibited phorbol ester-induced increase in ear thickness in BALB/c mice. Moreover, topical application of K6PC-9p suppressed dust mite extract-induced AD-like skin lesions in NC/Nga mice. Histopathological analysis revealed that both ear swelling and leucocyte infiltration were suppressed by K6PC-9p treatment. K6PC-9p also suppressed IL-4 and TNF-alpha expression in the ears and mast cell infiltration into the ears in NC/Nga mice. Further study demonstrated that K6PC-9p inhibited ConA-induced IL-4 secretion and LPS-induced macrophage activation. Taken together, our results showed that topical application of K6PC-9p exerts beneficial effects in animal model of skin inflammation and AD, suggesting that K6PC-9p might be a promising topical agent for the treatment of inflammatory skin diseases.

On the role of breastfeeding in health promotion and the prevention of allergic diseases

Based on animal models, we specify the major role of different bioactive milk components known to participate significantly in neonatal health promotion and in protection against a large number of infectious diseases and the development of allergies and asthma.

Environmental factors and allergic disorders

Despite numerous studies on possible associations between environmental exposure and allergic disorders, any conclusions made remain a matter of controversy. We conducted a review of evidence in relation to environmental and nutritional determinants and wheeze, asthma, atopic dermatitis, and allergic rhinitis. Identified were 263 articles for analysis after consideration of 1093 papers that were published since 2000 and selected by electronic search of the PubMed database using keywords relevant to epidemiological studies. Most were cross-sectional and case-control studies. Several prospective cohort studies revealed inconsistent associations between various environmental factors and the risk of any allergic disorder. Therefore, the evidence was inadequate to infer the presence or absence of a causal relationship between various environmental exposures and allergic diseases. However, evidence is suggestive of positive associations of allergies with heredity. Because almost all the studies were performed in Western countries, the application of these findings to people in other countries, including Japan, may not be appropriate. Further epidemiological information gained from population-based prospective cohort studies, in particular among Japanese together with other Asians, is needed to assess causal relationships between various environmental factors and allergic diseases.

Environmental factors, parental atopy and atopic eczema in primary-school children: a cross-sectional study in Taiwan

BACKGROUND

Parental atopy and environmental exposure are recognized risk factors for atopic eczema (AE) in childhood. However, the relative contributions of specific risk factors and the overall contributions of hereditary and environmental exposure remain unexplored.

OBJECTIVES

To identify risk factors, estimate the population attributable risk (PAR) of environmental exposure, and compare the AE data for boys vs. girls in primary-school children.

METHODS

During a February to June 2001 cross-sectional, Taiwan-based questionnaire survey, we investigated 23 980 children from 22 primary schools, all located within 1 km of an air-monitoring station.

RESULTS

The 12-month prevalence of AE was reported as 6.1% in boys and 4.9% in girls. In both sexes, the risk of AE was strongly associated with parental atopy and perceived ambient air pollution. The presence of cockroaches [odds ratio (OR) 1.18, 95% confidence interval (CI) 1.00-1.40] and visible mould on walls at home (OR 1.46, 95% CI 1.22-1.70) were also significantly related to AE for girls; however, only visible mould on walls (and not the presence of cockroaches) at home was related to AE for boys (OR 1.40, 95% CI 1.18-1.66). While mutually adjusted models were applied, we found adjusted ORs and PARs were similar in boys and girls in hereditary and outdoor environmental factors. The PAR of indoor environmental factors was higher in girls (8.4%) than in boys (5.5%). There was no interaction between parental atopy and environmental factors.

CONCLUSIONS

Parental atopy contributed more to AE than indoor or outdoor environmental factors. Girls may be more susceptible to indoor environmental factors than boys.

Increasing prevalence of atopic eczema in Taiwanese adolescents from 1995 to 2001

BACKGROUND

The prevalence of atopic eczema in adolescents has recently been reported as increasing in many countries, a phenomenon yet to be fully explained. This study compared the prevalence of atopic eczema among Taiwanese adolescents with individual-level risk factors and community-level data of temperature, relative humidity, and air pollutants to determine whether changes in these factors could explain the observed change in prevalence.

METHODS

We conducted two nationwide, cross-sectional surveys of atopic illness and symptoms among Taiwanese 12-15-year-old schoolchildren in 1995-1996 and 2001. The effects of personal and environmental factors were assessed and temporal changes of outdoor monitoring data were also compared with the prevalence difference of atopic eczema.

RESULTS

A total of 42 919 adolescents from the 1995 to 1996 survey and 10 215 adolescents from the 2001 survey attended schools located within 1 km of 22 monitoring stations. The 12-month prevalence of atopic eczema increased significantly during this period [adjusted prevalence ratio (PR)=1.43, 95% confidence interval (CI) 1.21-1.70 in boys; PR=1.77, 95% CI 1.49-2.10 in girls]. After adjustment for potential risk factors, the prevalence differences were statistically unchanged. Although parental education level contributed the most, changes in personal and environmental factors might not explain the observed prevalence increases of atopic eczema. Temporal change in the relative humidity was significantly associated with prevalence increase among boys but its contribution was also small.

CONCLUSION

Correlates of the investigated risk factors that have changed over time still underlie the prevalence increases of atopic eczema in Taiwanese adolescents. The exact reasons for the rising trends remain to be elucidated.

Is breast feeding a risk factor for eczema during the first year of life?

Breast feeding (BF) provides many advantages to the offspring; however, at present there is an ongoing debate as to whether or not it prevents allergic diseases. The aim of the current study was to investigate the effect of duration of BF on eczema in the first year of life. A birth cohort of 1128 infants was followed prospectively from 5 months of pregnancy. Data were collected using questionnaires, a medical examination and blood tests for allergy at the age of 1 yr. Breast feeding was not statistically significant associated with eczema in the first year of life [adj ORs with 95% CIs: 0.8 (0.4-1.3), 0.8 (0.5-1.3) and 1.0 (0.6-1.5) for BF duration of 1-6 wk, 7-12 wk and > or = 13 wk, respectively]. Eczema was positively associated with atopy and educational level of the mother, use of antibiotics in pregnancy and passive smoking by the child during the first 12 months. Regular postnatal contact of the infants with dogs was inversely associated with eczema. Breast feeding was positively associated with eczema among children with non-atopic parents [adj ORs with 95% CIs: 2.1 (0.4-10.6), 2.2 (0.4-11.3) and 1.9 (0.4-8.5) for BF duration of 1-6 wk, 7-12 wk and > or = 13 wk, respectively], whereas an inverse association was found among children with atopic parents [adj ORs with 95% CIs: 0.6 (0.3-1.3), 0.7 (0.3-1.4) and 0.9 (0.5-1.7) for the same BF durations]. However, these associations were not statistically significant. Breast feeding has no significant effect on the prevalence of eczema in the first year of life. The effect of BF on eczema in children depends on parental atopy.

A common mitochondrial haplogroup is associated with elevated total serum IgE levels

BACKGROUND

Maternal history of asthma or atopy is among the most consistently reported risk factors for asthma and atopy in children, yet the molecular basis for this observation remains unclear. Mitochondria are inherited exclusively through the maternal line, raising the possibility that sequence variation in the mitochondrial genome contributes to the pathogenesis of asthma and atopy.

OBJECTIVE

We set out to determine whether common European mitochondrial haplogroups are associated with asthma-related atopic phenotypes.

METHODS

We studied 654 self-reported white children age 5 to 12 years with mild to moderate asthma participating in the Childhood Asthma Management Program. Eight haplogroup-tagging polymorphisms were genotyped with TaqMan probe hybridization assays, and mitochondrial haplogroup tests of association with asthma-related and atopy-related phenotypes were performed with haplo.stats.

RESULTS

We found significant evidence of mitochondrial haplogroup association with total serum IgE levels (global significance, P = .04), with carriers of European haplogroup U (frequency 11%) having higher total serum IgE levels (median level, 684 IU/L) compared with noncarriers (389 IU/L; P = .001). Haplogroup U carriers also had trends of greater skin prick test reactivity (P = .03) and higher frequency of atopic dermatitis (P = .07), although global haplogroup tests for these later 2 phenotypes were not significant at an alpha level of 0.05.

CONCLUSION

These data are the first to suggest that common mitochondrial haplogroups influence the atopic diathesis.

CLINICAL IMPLICATIONS

These findings may provide a molecular explanation for the prominent influence of maternal history of atopy on the development of atopy in offspring.

The treatment of severe atopic dermatitis in childhood with narrowband ultraviolet B phototherapy

BACKGROUND

There is a lack of data regarding the use of narrowband ultraviolet B (NB-UVB) phototherapy in children with atopic dermatitis (AD). Many centres use this mode of treatment for children with AD; however, there have only been two previous studies observing the effect of NB-UVB in children with AD.

AIM

We undertook a retrospective review of children with severe eczema who had undergone NB-UVB consecutively in our department between 1999 and 2005.

METHODS

All children with AD who had undergone NB-UVB consecutively in our department between 1999 and 2005 were identified from the phototherapy database. Their clinical notes were reviewed for information on age, sex, skin type, minimal erythema dose (MED), adjuvant therapy, previous therapy, adverse effects, number of exposures, cumulative dose, response to treatment and length of remission.

RESULTS

In total, 50 children (83%) completed more than 10 exposures of NB-UVB. Complete clearance or minimal residual activity was achieved in 20 children (40%). A good improvement was achieved in a further 10 children (23%), and a moderate improvement in 13 (26%). Children with MEDs > 390 mJ/cm2 were more likely to clear, and this was found to be statistically significant (P = 0.02). Overall, the treatment was well tolerated and the median length of remission was 3 months.

CONCLUSION

NB-UVB is an effective treatment for children with severe AD. Children with MEDs > 390 mJ/cm2 are more likely to clear. Further studies are needed to evaluate the efficacy of NB-UVB and long-term safety in treating children with severe AD.

Early allergen exposure and atopic eczema

BACKGROUND

The relationship between exposure to indoor aeroallergens in early life and subsequent eczema is unclear. We have previously failed to show any significant associations between early life exposure to house dust mite and cat fur allergens and either sensitization to these allergens or wheeze. We have also previously reported a lower prevalence of parent-reported, doctor-diagnosed eczema by age 2 years for children exposed to higher concentrations of house dust mite, but no other associations with other definitions of eczema or for exposure to cat allergen.

OBJECTIVES

To extend the exposure-response analysis of allergen exposure and eczema outcomes measured up to age 8 years, and to investigate the role of other genetic and environmental determinants.

METHODS

A total of 593 children (92 x 4% of those eligible) born to all newly pregnant women attending one of three general practitioner surgeries in Ashford, Kent, were followed from birth to age 8 years. Concentrations of house dust mite and cat allergen were measured in dust samples collected from the home at 8 weeks after birth. The risk of subsequent eczema as defined by the U.K. diagnostic criteria was determined according to different levels (quintiles) of allergen exposure at birth.

RESULTS

By age 8 years, 150 (25 x 3%) children had met the diagnostic criteria for eczema at least once. Visible flexural dermatitis was recorded at least once for 129 (28 x 0%). As in other studies, parental allergic history was positively associated with most eczema outcomes, as were higher maternal education and less crowded homes. No clear linear associations between early exposure to house dust mite or cat allergen were found, regardless of the definition of eczema used. The risk of eczema appeared to increase for the three lowest quintiles of house dust mite allergen exposure (odds ratio, OR 1 x 37 for third quintile compared with first), and then to fall for the two highest quintiles (OR 0 x 66 and 0 x 71) even after controlling for confounding factors.

CONCLUSIONS

The lack of any clear exposure-disease relationship between allergens in early life and subsequent eczema argues against allergen exposure being a major factor causing eczema. If the lower levels of eczema at higher levels of house dust mite are confirmed, then interventions aimed at reducing house dust mite in early infancy could paradoxically increase the risk of subsequent eczema.

Early-life risk factors for occurrence of atopic dermatitis during the first year

OBJECTIVE

In a prospective birth cohort study, we sought to identify perinatal predictors of the occurrence of atopic dermatitis in the first year of life.

METHODS

Associations of family history, infection during pregnancy, cord blood cytokine concentrations, and skin function parameters with atopic dermatitis were analyzed. Stratum corneum hydration was measured with an impedance meter until 5 days after delivery and again at 1 month.

RESULTS

Complete data were obtained for 213 infants, including 27 diagnosed by a physician as having atopic dermatitis during their first year and 26 diagnosed as having infantile eczema during their first month. The risk of atopic dermatitis during the first year of life was related to maternal atopic dermatitis, lower concentrations of macrophage inflammatory protein-1beta in cord blood, and greater skin moisture in the surface and stratum corneum of the forehead and cheek at 1 month of age but not to viral or bacterial infection during pregnancy or breastfeeding. Paternal hay fever was associated negatively with the development of atopic dermatitis. High concentrations of interleukin-5, interleukin-17, and macrophage chemotactic protein-1 and only surface moisture in the cheek were associated with greater risk of infantile eczema in the first month.

CONCLUSIONS

The association of atopic dermatitis in infancy with reduced neonatal macrophage inflammatory protein-1beta levels suggests a link with immature immune responses at birth. Stratum corneum barrier disruption in atopic dermatitis may involve impairment of cutaneous adaptation to extrauterine life. The majority of risk factors had different effects on infant eczema and atopic dermatitis, indicating different causes.

Prebiotics and synbiotics: two promising approaches for the treatment of atopic dermatitis in children above 2 years

BACKGROUND

Appropriate use of prebiotics and optimal combinations of probiotics and prebiotics (synbiotics) could allow significantly better results to be obtained in the treatment of atopic dermatitis (AD).

OBJECTIVE

To evaluate the efficiency of synbiotics when compared with prebiotics alone (control group) in the treatment of moderate and severe AD in children aged 2 years and over.

METHODS

Double-blind prospective randomized study performed on children aged at least 2 years presenting AD with a minimum SCORing Atopic Dermatitis (SCORAD) score of 15. A dose of 1.2 x 10(9) colony-forming units Lactobacillus rhamnosus Lcr35 plus prebiotic preparation or an identically appearing prebiotic preparation alone was given three times a day for 3 months. Patients' diet and usual treatment for AD remained unchanged during the study period. Efficiency was evaluated using the SCORAD score. Use of topical drugs was noted.

RESULTS

A total of 48 patients were originally enrolled; nine did not complete the study. In synbiotic group, the mean values of the total SCORAD score was 39.1 before treatment vs 20.7 after 3 months of treatment (P < 0.0001). In the prebiotic group, the mean of the total SCORAD score was 39.3 before the treatment vs 24.0 after 3 months (P < 0.0001). After 3 months of treatment, no statistical differences between the two treatment groups with regard to the total SCORAD score were noted (P = 0.535). Neither were there any statistical differences in the total use of ointment between patients receiving prebiotics or synbiotics (P = 0.966) over the study period. Tolerance was excellent in both groups.

CONCLUSIONS

Both synbiotics and prebiotics used alone seem able to significantly improve the manifestations of AD in children aged 2 years and over.

Familiar and environmental factors influencing atopic dermatitis in the childhood

BACKGROUND

The increase in the incidence of atopic dermatitis (AD) in developed countries has been related to familiar and environmental factors. This survey was undertaken to investigate the family background, birthweight and the home environment of children suffering from AD in order to point out the possible factors that provoke the development of the disease.

METHODS

The study uses data collected by means of self-administered questionnaires and discusses 461 cases of children (age 0-12) with active skin signs of AD. The control group comprised of 343 children (age 0-12) with no skin signs or positive lifetime history of AD. Associations between familiar and various home environmental factors and the risk of AD were calculated by means of odds ratios.

RESULTS

There were statistically significant positive associations between atopic eczema symptoms and higher birthweight, small households, wall-to-wall carpets, as well as indoor-kept pets. Day-nursery attendance, heating system and indoor smoking, however, did not significantly alter the risk of the disease.

CONCLUSIONS

Because of the limitations of a retrospective questionnaire study, further research is needed to confirm these associations and clarify whether they are causative.

The predictive value of early life total immunoglobulin E measurement in identifying atopic children in a population-based birth cohort study

Atopy is common and the prevalence amongst children is rising. Measurements in early childhood that can predict subsequent development of atopy could be clinically useful for targeting preventive measures. We used the Children in Focus (CiF) subgroup of a large population-based birth cohort study (the Avon Longitudinal Study of Parents and Children) to investigate whether total immunoglobulin E (IgE) measured at 12 and 18 months could predict subsequent development of atopy at 5 yr of age. Atopy was determined by positive skin prick test (> or = 3 mm wheal) to one or more of 14 inhalant and food allergens. Prevalence of skin prick positivity to any allergen was 14.5% (104 of 715; 95% CI: 12.0-17.1%). Total IgE levels were significantly higher at 12 months of age (p < 0.0005) but not 18 months of age in those children subsequently atopic. The highest positive predictive value was 41% with an IgE measurement of >51 kU/l, with a sensitivity of 13.5% and a specificity of 95.8%. Although significant differences in early life IgE measurements were seen, the extent of overlap was great, such that the overall performance of IgE at 12 months as a screening test for atopy was poor.

Atopic dermatitis, extrinsic atopic dermatitis and the hygiene hypothesis: results from a cross-sectional study

BACKGROUND

Atopic Dermatitis (AD), hayfever and asthma are commonly summarized as atopic diseases. The spatial distribution of AD differs from that of asthma and hayfever, suggesting that AD might follow a different risk pattern than these diseases. AD can be differentiated into an allergic extrinsic form (EAD) and a non-allergic intrinsic form (IAD). Only EAD might follow the distribution and risk pattern that have been ascribed to asthma and hayfever.

OBJECTIVE

To investigate the distribution and risk factor profile of AD and EAD focusing on environmental factors relating to the hygiene hypothesis.

METHODS

Population-based cross-sectional study on 12,601 children aged 5-7 and 9-11 years from Dresden (Eastern Germany) and Munich (Western Germany). Information was obtained by International Study of Asthma and Allergic Childhood questionnaires, dermatological examinations and skin prick testing. AD-diagnosis ever, current AD-symptoms and visible eczema were investigated with their respective extrinsic forms.

RESULTS

Maternal and paternal history of AD were equally strong determinants of the child's AD status. Factors related to the hygiene hypothesis like day-care attendance and number of older siblings were not associated with a decreased risk of AD. The proportion of EAD within AD was higher in Eastern than in Western Germany. The determinants of the diseases appeared to be similar for both EAD and IAD.

CONCLUSIONS

There was no evidence of the hygiene hypothesis holding true for AD or EAD. AD might be a separate entity than respiratory atopic diseases. Little is known about the risk factors of AD and factors different from those of respiratory allergic diseases should be considered in future research.

Atopic dermatitis

Atopic dermatitis (AD) is commonly associated with immunoglobulin E (IgE) antibody-related mechanisms, which are the focus of this article. The vast majority of patients with AD exhibit hyperproduction of IgE, particularly during disease onset or flare. IgE-dependent late-phase reactions may influence the chronic inflammatory response in AD. Clearly, genetics plays a major role in determining who develops AD. However, the recent increase in AD prevalence suggests that a complex interaction between environmental factors and susceptibility genes results in clinical expression of the disorder. These immunologic "triggers" differ among individuals and include various foods, airborne allergens, irritants and contactants, hormones, stress, climate, and microorganisms. Although much about AD remains to be elucidated, our current understanding of its pathophysiology has provided clinicians with the ability to construct more rational therapeutic interventions, including multiple-agent regimens that provide both immediate relief and effective long-term management. Future advances will come from identification of the genes causing this disease and further elucidation of the immunoregulatory mechanisms involved in the pathogenesis of AD.

A comparison between criteria for diagnosing atopic eczema in infants

BACKGROUND

Epidemiological studies have shown different estimates of the frequency of atopic eczema (AE) in children. This may be explained by several factors including variations in the definition of AE, study design, age of study group, and the possibility of a changed perception of atopic diseases. The role of IgE sensitization in AE is a matter of debate.

OBJECTIVES

To determine the prevalence and cumulative incidence of AE in a group of unselected infants followed prospectively from birth to 18 months of age using different diagnostic criteria; to evaluate the agreement between criteria; and to describe the association between atopic heredity and postnatal sensitization, respectively, and the development of AE according to the different diagnostic criteria.

METHODS

During a 1-year period a consecutive series of 1095 newborns and their parents were approached at the maternity ward at the Odense University Hospital, Denmark and a cohort of 562 newborns was established. Infants were examined and followed prospectively from birth and at 3, 6, 9, 12 and 18 months of age. AE was diagnosed using four different criteria, the Hanifin and Rajka criteria, the Schultz-Larsen criteria, the Danish Allergy Research Centre (DARC) criteria developed for this study and doctor-diagnosed visible eczema with typical morphology and atopic distribution. Additionally, the U.K. diagnostic criteria based on a questionnaire were used at 1 year of age. Agreement between the four criteria was analysed at each time point and over time, and agreement between the four criteria and the U.K. questionnaire criteria was analysed.

RESULTS

The cumulative 1-year prevalence of AE using the Hanifin and Rajka criteria was 9.8% (95% confidence interval, CI 7-13%), for the Schultz-Larsen criteria it was 7.5% (95% CI 5-10%), for the DARC criteria 8.2% (95% CI 6-11%), for visible eczema 12.2% (95% CI 9-16%) and for the U.K. criteria 7.5% (95% CI 5-10%). The pairwise agreement between criteria showed good agreement, with rates varying between 93% and 97% and kappa scores between 0.6 and 0.8. Agreement analysis of diagnoses between the four criteria demonstrated that cumulative incidences showed better agreement than point prevalence values.

CONCLUSIONS

Agreement between different criteria for diagnosing AE was acceptable, but the mild cases constituted a diagnostic problem, although they were in the minority. Repeated examinations gave better agreement between diagnostic criteria than just one examination. Atopic heredity was less predictive for AE than sensitization to common food and inhalant allergens in early childhood.