Worldwide variations in prevalence of symptoms of allergic rhinoconjunctivitis in children: the International Study of Asthma and Allergies in Childhood (ISAAC)

Allergic airway diseases in childhood - marching from epidemiology to novel concepts of prevention

In the past years, a wide range of epidemiological, clinical, and experimental studies have produced remarkable advances in the field of respiratory allergies in childhood. By the recent investigations on epidemiological trends, risk factors, and prevention of asthma and allergic rhinitis, various exiting concepts have been challenged, and novel innovative approaches have been developed. Pediatric Allergy and Immunology (PAI), with a number of highly relevant contributions between 2010 and 2012, has become an important forum in this area. The prevalence of asthma in some developed countries may have reached a plateau, while in developing countries, where the prevalence was previously low, allergic diseases are still on the increase. A wide array of risk and protective factors, including hygiene, infections, outdoor and indoor air pollution, allergen exposure, breast-feeding practices, nutrition, and obesity, play a multifaceted role in shaping the observed worldwide trends of respiratory allergies. Under the guidance of recent research, prediction and prevention strategies in the clinical practice are progressively changing, the focus moving away from avoidance of allergen exposure and toward tolerance induction.

Interaction between IL13 genotype and environmental factors in the risk for allergic rhinitis in Korean children

BACKGROUND

The prevalence of allergic rhinitis (AR) is increasing worldwide. Allergic diseases develop in susceptible subjects when they are exposed to specific environmental factors.

OBJECTIVE

We analyzed changes in the prevalence of AR and identified genetic and environmental factors in early childhood that affect risk.

METHODS

We used the International Study of Asthma and Allergies in Childhood questionnaire to collect data on AR, allergies, and environmental exposures from 4554 elementary school students from 5 areas of Seoul, Korea, in 2008. We also obtained DNA from 1050 subjects from 1 area of Seoul for genotype analysis of IL13.

RESULTS

We identified genetic and environmental factors during infancy and early childhood that increased the risk for current AR (resulting in a diagnosis of AR and AR symptoms in the past 12 months) in elementary school-aged children. These included allergic disease in parents and antibiotic use in infants, allergic disease in parents and exposure of infants to mold, and allergic disease in parents and moving an infant to a newly built house. The risk of current AR also increased in subjects with GA or AA at nucleotide 2044 in IL13 who had been exposed to mold in the home during infancy (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11) compared with subjects who had GG at this position and had not been exposed to mold (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11).

CONCLUSION

The prevalence of AR is increasing in Korean children. Children with a family history of allergic disease and exposure to specific environmental risk factors during infancy are more likely to have AR. Children with GA or AA at IL13(+2044) are at increased risk for AR when exposed to mold in the home during the first year of life.

Time trends and risk factors for rhinoconjunctivitis in New Zealand children: an International Study of Asthma and Allergies in Childhood (ISAAC) survey

AIM

To investigate prevalence, time trends and factors associated with rhinitis and rhinoconjunctivitis not related to acute infections in New Zealand.

METHODS

The International Study of Asthma and Allergies in Childhood (ISAAC) surveyed children aged 6-7 and 13-14 years for symptoms of these conditions. Five New Zealand centres were surveyed on two occasions (Phase One and Phase Three) 8-10 years apart. In Phase Three, questions were included on environmental factors, which might be associated with rhinoconjunctivitis. We report findings related to symptoms of rhinoconjunctivitis among 24 190 New Zealand children.

RESULTS

Symptoms of rhinoconjunctivitis in the past year were reported in 11.4% of 6- to 7-year-old children and 18% of 13- to 14-year-old adolescents in Phase Three compared with 9.5 and 19.1%, respectively, in Phase One. Severe symptoms of rhinoconjunctivitis were reported in 0.5% of children and 0.8% of adolescents. Current symptoms were more common in males at 6-7 years and in females of 13-14 years, and Māori and Pacific Island ethnic groups had higher prevalence compared with those of European descent, especially in the older age group. For immigrant children, there was a very strong positive relationship between symptoms and length of time resident in New Zealand, supporting the probable importance of environmental factors. A positive association was found between symptoms and use of paracetamol in infancy or in the last year, and weaker associations were noted for antibiotic use, exercise, and regular pasta ingestion.

CONCLUSIONS

Further study of environmental factors is recommended.

Changes over time in the relationship between symptoms of asthma, rhinoconjunctivitis and eczema: a global perspective from the International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND

The International Study of Asthma and Allergies in Childhood (ISAAC) identified trends in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema over a seven-year period. We hypothesised that environmental influences on the three diseases are different and therefore investigated the correlation over time between trends in the prevalence of these diseases and their combinations at centre and individual level.

METHODS

Centre level analyses were correlations between time trends in the prevalence of symptoms. At an individual level, odds ratios were calculated for associations between symptoms between Phases One and Three. We also investigated potential effect modification in the younger versus older age group; male versus female; and by average Gross National Income per capita (GNI).

RESULTS

Both phases were completed in 66 centres in 37 countries for the 6-7 year age group and in 106 centres in 56 countries for the 13-14 year age group. We found that the correlations in time trends were stronger for the older age group than the younger one. Between symptoms of diseases, correlations of time trends were the strongest for rhinoconjunctivitis with eczema and weakest for eczema with asthma. The relationship between the three diseases was generally consistent over the seven-year period, and there was little association found with average GNI.

CONCLUSIONS

Despite some increase in the proportion of children with symptoms of asthma, rhinoconjunctivitis and eczema, the pattern between the three diseases has not changed much, suggesting that similar factors may be affecting them at a global level.

Polymorphisms in the IL4 gene, smoking, and rhinoconjunctivitis in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

Epidemiological evidence on the relationship between IL4 single nucleotide polymorphisms (SNPs) and allergic rhinitis is limited. We conducted a case-control study to investigate this issue in young adult Japanese women. Included were 393 women who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Controls were 703 women without rhinoconjunctivitis based on the ISAAC criteria who had not been diagnosed with allergic rhinitis and/or asthma by a doctor. Compared with the TT genotype of IL4 SNP rs2227284, the GG genotype, occurring in 10.2% of control subjects, was significantly inversely associated with the risk of rhinoconjunctivitis: the adjusted OR was 0.60 (95% CI: 0.37-0.98). There were no significant relationships between SNP rs2243250, rs2070874, or rs2243290 and rhinoconjunctivitis. None of the haplotypes were significantly related to rhinoconjunctivitis. A significant inverse relationship between the combination of the TG and GG genotypes of SNP rs2227284 and rhinoconjunctivitis was observed in women who had never smoked, but not in those who had ever smoked (P for interaction=0.11). This is the first study to demonstrate a significant relationship between IL4 SNP rs2227284 and rhinoconjunctivitis. Smoking may modify the relationship between SNP rs2227284 and rhinoconjunctivitis.

Nasal eosinophilia as a marker for allergic rhinitis: a controlled study of 50 patients

Eosinophils are the principal effector cells involved in the pathogenesis of allergic inflammation. We conducted a study to investigate the validity of the nasal smear examination for detecting eosinophilia in patients with allergic rhinitis. Our study group was made up of 50 patients with allergic rhinitis and 50 age- and sex-matched controls without allergic rhinitis. Smears were obtained from nasal secretions in both groups and then fixed, stained, and studied under light microscopy. Statistical analysis revealed that the odds ratio for eosinophilia positivity in nasal smears in the rhinitis group was 25.61 with a 95% confidence interval of 8 to 78. The sensitivity, specificity, positive predictive value, and negative predictive value of this test were 74, 90, 88, and 77%, respectively. We conclude that the nasal eosinophilia test is highly specific and moderately sensitive in diagnosing allergic rhinitis, and that it therefore can be used as an easy, noninvasive, and inexpensive procedure for screening patients and for conducting epidemiologic studies of this disorder.

The effect of cigarette smoking on allergic conditions in Maltese children (ISAAC)

Maltese children are frequently exposed to tobacco smoke through passive and personal smoking. In the phase 3 ISAAC study questionnaire, we enquired about passive smoking to the parents of 3816 (80% response rate) 5- to 8-yr-old children and about passive and personal smoking to 4139 (90% response rate) 13- to 15-yr-old participating children. Thirty-one percent of 5- to 8-yr olds were passive smokers with their father more likely to be the smoker (p < 0.0001). Maternal smoking in the first year of the child's life resulted in the children having an increased chance of wheezing 'ever' (p < 0.001), exercise-induced wheezing (p < 0.05) and being diagnosed with asthma (p < 0.0001). Current smoking by the mother also led to the child having current rhinitis (p < 0.001). Fifty-one percent of 13- to 15-yr olds were passive smokers again with the father more likely to be the smoker (p < 0.0001). Maternal (p < 0.0001) and paternal smoking (p < 0.05) resulted in the children having an increased chance of wheezing sometime in their life, exercise-induced wheezing, nocturnal cough, and being diagnosed with asthma. Current smoking by the mother was more common in children having current rhinitis (p < 0.05), while current smoking by both mother and/or father led to itchy/watery eyes accompanying rhinitis (p < 0.05). Recurrent itchy rashes were also more likely in passive smokers (p < 0.001). Personal smoking by the 13- to 15-yr olds (8.15% boys vs. 8.8% girls ns ) resulted in a higher cumulative prevalence of wheezing (p < 0.0001), rhinitis (p < 0.05), and recurrent itchy rash (p < 0.001) but only affected current prevalence of wheezing (p < 0.0001). These smokers were more likely to experience exercise-induced wheezing (p < 0.0001), nocturnal cough (p < 0.0001), and being diagnosed with asthma (p < 0.05) and eczema (p < 0.001). Children smoking more than 10 cigarettes/day persisted with wheezing (p = 0.04) had more frequent episodes of exercise-induced wheeze (p = 0.04), nocturnal cough (p < 0.0001), and rhinoconjunctivitis (p = 0.02) than milder smokers. Smoking seems to be affecting childhood allergies in Maltese children quite significantly.

Prevalence and associated risk factors of allergic rhinitis in preschool children in Beijing

OBJECTIVES/HYPOTHESIS

To investigate the prevalence of allergic rhinitis (AR) and its associated risk factors in preschool children in Beijing.

STUDY DESIGN

Two-stage, clustered, stratified random sample study.

METHODS

Parents of 4,075 children aged 3, 4, and 5 years in urban and suburban areas were surveyed using a questionnaire. A random subgroup of 1,067 children was examined by otolaryngologists with skin prick test (SPT).

RESULTS

The survey response rate was 98.3%. Based on the criteria published by ARIA document, the prevalence of epidemiologic AR was 48% (53.2% in urban areas; 43.4% in suburban areas). Among 795 children with epidemiologic AR, sensitization to common inhalant allergens was confirmed by a positive SPT in 248 children (31.2%). Thus, the adjusted prevalence of clinical AR was 14.9% (19.5% in urban areas; 10.8% in suburban areas). In these AR children, 166 (67.1%) were intermittent and 82 (32.9%) persistent, with moderate/severe symptoms in 103 (41.5%). The most common inhalant allergens were Alternaria tenuis (55.7%), followed by Dermatophagoides farina (39.4%), and Dermatophagoides pteronyssinus (38.6%). Both asthma (adjusted OR 4.88, 95% CI: 3.48-6.86) and eczema (adjusted OR: 1.49, 95% CI: 1.15-1.94) appear to be significant concomitant risk factors for AR.

CONCLUSIONS

The prevalence of AR in young children can be overestimated using epidemiologic criteria. AR is a common disease in Asian preschool children, with an increasing trend as children get older, and is higher in urban than suburban areas--suggesting an important role for environmental risk factors in AR.

Molecular spreading and predictive value of preclinical IgE response to Phleum pratense in children with hay fever

BACKGROUND

IgE sensitization against grass pollen is a cause of seasonal allergic rhinitis.

OBJECTIVE

We sought to investigate the evolution at the molecular level and the preclinical predictive value of IgE responses against grass pollen.

METHODS

The German Multicentre Allergy Study examined a birth cohort born in 1990. A questionnaire was administered yearly, and blood samples were collected at 1, 2, 3, 5, 6, 7, 10, and 13 years of age. Grass pollen-related seasonal allergic rhinitis (SARg) was diagnosed according to nasal symptoms in June/July. Serum IgE antibodies to Phleum pratense extract and 8 P pratense molecules were tested with immune-enzymatic singleplex and multiplex assays, respectively.

RESULTS

One hundred seventy-seven of the 820 examined children had SARg. A weak monomolecular/oligomolecular IgE response to P pratense was observed very frequently before SARg onset. These initial IgE responses increased in concentration and molecular complexity during the preclinical and clinical process. A typical progression of IgE sensitization was observed: Phl p 1 (initiator in >75% of cases); then Phl p 4 and Phl p 5; then Phl p 2, Phl p 6, and Phl p 11; and then Phl p 12 and Phl p 7. At age 3 years, IgE sensitization predicted SARg by age 12 years (positive predictive value, 68% [95% CI, 50% to 82%]; negative predictive value, 84% [95% CI, 80% to 87%]). At this preclinical prediction time, the number of recognized molecules and the serum levels of IgE to P pratense were significantly lower than at 3 or more years after SARg onset.

CONCLUSIONS

The IgE response against grass pollen molecules can start years before disease onset as a weak monosensitization or oligosensitization phenomenon. It can increase in serum concentration and complexity through a "molecular spreading" process during preclinical and early clinical disease stages. Testing IgE sensitization at a preclinical stage facilitates prediction of seasonal allergic rhinitis at its molecular monosensitization or oligosensitization stage.

Increased exhaled nitric oxide predicts new-onset rhinitis and persistent rhinitis in adolescents without allergic symptoms

BACKGROUND

The fraction of nitric oxide in exhaled air (FE(NO)) is increased in rhinitis and asthma. We have previously suggested that elevated FE(NO) levels in the absence of asthma symptoms may be a sign of 'early asthma'. In the present study, we hypothesize that elevated exhaled NO levels may also precede rhinitis symptoms.

OBJECTIVE

To investigate in a cohort of adolescents whether or not increased exhaled NO levels at the age of 13-14 years predicted new-onset or persistent rhinitis within a 4-year period.

METHODS

A total of 959 randomly selected adolescents (13-14 years) completed a questionnaire on respiratory symptoms at baseline and follow-up, 4 years later. Exhaled NO was measured at baseline. After exclusion of subjects with asthma diagnosis or asthma symptoms at baseline, 657 participants were eligible for the present study.

RESULTS

Higher FE(NO) levels at baseline were associated with increased risk for new-onset (P = 0.009) and persistent rhinitis (P = 0.03) within a 4-year period. The risk of new-onset rhinitis was 2.32 (1.23, 4.37) [OR (95% CI)] times higher if FE(NO) > 90th percentile of the group without rhinitis at baseline. This increased risk for new-onset rhinitis was significant [2.49 (1.24, 5.01)] after excluding subjects with allergic symptoms. The risk of persistent rhinitis was 5.11 (1.34, 19.57) times higher if FE(NO) > 90th percentile of the group without rhinitis at baseline.

CONCLUSION

Elevated exhaled nitric oxide levels predicted incident and persistent rhinitis in this population-based study of adolescents. Moreover, these findings were consistent after excluding subjects with allergic symptoms. Thus, it appears that elevation of exhaled NO precedes airway symptoms and predicts development of rhinitis in subjects without allergic symptoms or family history of allergic disease.

Childhood atopic diseases and early life circumstances: an ecological study in Cuba

Background

Children are especially vulnerable during periods of resource shortage such as economic embargoes. They are likely to suffer most from poor nutrition, infectious diseases, and other ensuing short-term threats. Moreover, early life circumstances can have important consequences for long-term health. We examined the relationship between early childhood exposure to the Cuban economic situation in the nineties and the occurrence of atopic diseases later in childhood.

Methodology/Principal Findings

A cross-sectional study of 1321 primary schoolchildren aged 4–14 was conducted in two Cuban municipalities. Asthma, allergic rhinoconjunctivitis and atopic dermatitis were diagnosed using the International Study of Asthma and Allergies in Childhood questionnaire. Children were divided into three groups of exposure to the economic situation in the nineties according to birth date: (1) unexposed; (2) exposed during infancy; (3) exposed during infancy and early childhood. Associations were assessed using multiple logistic regression models. Exposure during infancy had a significant inverse association with the occurrence of asthma (OR 0.56, 95%CI 0.33–0.94) and allergic rhinoconjunctivitis (OR 0.46, 95%CI 0.25–0.85). The associations were stronger after longer exposure, i.e. during infancy and early childhood, for asthma (OR 0.40, 95% CI 0.17–0.95) and allergic rhinoconjunctivitis (OR 0.29, 95%CI 0.11–0.77). No significant associations were found for atopic dermatitis.

Conclusions/Significance

Exposure to the economic situation in the nineties during infancy and early childhood was inversely associated with asthma and allergic rhinoconjunctivitis occurrence later in childhood. We hypothesize that factors related to this period, such as infectious diseases and undernutrition, may have an attenuating effect on atopic disease development. The exact cause and underlying mechanisms need to be further elucidated.

A population-based 5-year follow-up of allergic rhinitis in Chinese children

BACKGROUND

There have been few longitudinal investigations of allergic rhinitis (AR) in Chinese children. We previously conducted an investigation of the prevalence of AR in 3- to 6-year old children for the year of 2005-2006. The aim of this study was to observe the natural course of AR in children in the previously investigated population during a cohort study for 5 years.

METHODS

A total of 1211 children in the previously investigated population were included in this study. Telephone interviews were conducted three times during the 1st, 3rd, and 5th year from the previous study.(14) Questions including duration, severity of nasal symptoms, asthma, and related problems of allergy were examined. Skin-prick tests (SPTs) were performed again on those children who had done SPTs in the previous study(14) after the last follow-up (i.e., after 5 years).

RESULTS

Of the 1211 children, 870 (71.8%) completed the 5-year observation period. In the 5th year, the prevalence of positive nasal symptoms was 29.4% (256 of the 870 children), including 64/70 (91.4%) of those who were formerly symptom positive and SPT(+), 45/104 (43.3%) of those who were formerly symptom positive and SPT(-), 40/66 (60.6%) of those who were formerly symptom positive with SPTs not performed (SPTs[x]), and 107/630 (17.0%) of those who were formerly symptom negative. SPT results showed that 96.1% (73/76) of previous SPT(+) children remained SPT(+); only 3.9% (6/154) became SPT(+) in previous SPT(-) children.

CONCLUSION

We concluded that the natural course of AR (symptom positive and SPT(+)) and non-AR (symptom positive and SPT(-)) children were quite different.

The relationship between exposure to microbial volatile organic compound and allergy prevalence in single-family homes

Microbial volatile organic compounds (MVOCs) are a type of VOCs produced by microorganisms. Exposure to 1-octen-3-ol, one of the known MVOCs, has been reported to reduce nasal patency and increase nasal lavage myeloperoxidase, eosinophil cationic proteins, and lysozymes in both experimental and field studies. We reported in a previous paper that 1-octen-3-ol exposure at home is associated with mucosal symptoms. In this study, our aim was to investigate the relationship between asthma and allergies and MVOC exposure in single-family homes. The subjects were 624 inhabitants of 182 detached houses in six regions of Japan. Air samples were collected using diffusive samplers, and the concentrations of eight selected MVOCs were analyzed using gas chromatography/mass spectrometry in selected-ion-monitoring mode. Each inhabitant of each of the dwellings was given a self-administered questionnaire. Among the 609 subjects who answered all of the questions about allergies, history of the medical treatment for asthma, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis within the preceding two years was 4.8%, 9.9%, 18.2%, and 7.1%, respectively. A significant association between 1-octen-3-ol (per log(10) unit) and allergic rhinitis odds ratio (OR): 4.10, 95% confidence interval (CI): 1.71 to 9.80 and conjunctivitis (OR: 3.54, CI: 1.17 to 10.7) was found after adjusting for age, sex, tobacco, wall-to-wall carpeting, signs of dampness, history of treatment for hay fever, and other potentially relevant environmental factors. No relationships were found between any MVOCs and asthma or atopic dermatitis after the adjustment. The levels of MVOCs and airborne fungi were only weakly correlated. These results are consistent with previous studies that have associated higher levels of 1-octen-3-ol exposure with increased irritation of nasal and ocular mucosae. Although the indoor-air concentrations of 1-octen-3-ol found in this study were relatively low, we conclude that exposure to MVOC may be related to rhinitis and conjunctivitis.

Allergic rhinitis in children

Allergic rhinitis affects up to 40% of children but is commonly undiagnosed. Careful assessment of nasal symptoms allows for the most appropriate therapeutic options to be chosen. Allergen avoidance is often difficult in practice. Antihistamines are of limited benefit in allergic rhinitis caused by house dust mite and other perennial allergens, where symptoms, predominantly nasal obstruction, are not histamine mediated. In contrast, symptoms triggered by pollen, such as nasal itch, rhinorrhoea and sneezing, are relieved by antihistamines. Intranasal steroids are the treatment of choice for persistent moderate-severe allergic rhinitis and are more effective than antihistamines for relief of nasal obstruction. Failure to respond to intranasal medications is often caused by poor compliance or inefficient use of nasal sprays. Immunotherapy may be a useful, if expensive, option, particularly where symptoms are because of a specific pollen. The benefits of immunotherapy in house dust mite-induced rhinitis and asthma remain controversial.

Dietary meat and fat intake and prevalence of rhinoconjunctivitis in pregnant Japanese women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

Background

Dietary fat exerts numerous complex effects on proinflammatory and immunologic pathways. Several epidemiological studies have examined the relationships between intake of fatty acids and/or foods high in fat and allergic rhinitis, but have provided conflicting findings. The current cross-sectional study investigated such relationships in Japan.

Methods

Study subjects were 1745 pregnant women. The definition of rhinoconjunctivitis was based on criteria from the International Study of Asthma and Allergies in Childhood. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for age; gestation; region of residence; number of older siblings; number of children; smoking; secondhand smoke exposure at home and at work; family history of asthma, atopic eczema, and allergic rhinitis; household income; education; and body mass index.

Results

The prevalence of rhinoconjunctivitis in the past 12 months was 25.9%. Higher meat intake was significantly associated with an increased prevalence of rhinoconjunctivitis: the adjusted odds ratio between extreme quartiles was 1.71 (95% confidence interval: 1.25-2.35, P for trend = 0.002). No measurable association was found between fish intake and rhinoconjunctivitis. Intake of total fat, saturated fatty acids, monounsaturated fatty acids, n-3 polyunsaturated fatty acids, α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, n-6 polyunsaturated fatty acids, linoleic acid, arachidonic acid, and cholesterol and the ratio of n-3 to n-6 polyunsaturated fatty acid intake were not evidently related to the prevalence of rhinoconjunctivitis.

Conclusions

The current results suggest that meat intake may be positively associated with the prevalence of rhinoconjunctivitis in young adult Japanese women.

Smoking and prevalence of allergic disorders in Japanese pregnant women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Studies on the associations between smoking and allergic diseases have mostly focused on asthma. Epidemiological studies in adults on the effects of smoking on allergic diseases other than asthma, such as eczema and rhinoconjunctivitis, have been limited, and the information that is available has been inconsistent. The aim of this study was to investigate the association between smoking status and environmental tobacco smoke (ETS) exposure and the prevalence of allergic diseases.

METHODS

Study subjects were 1743 pregnant Japanese women. The definitions of wheeze and asthma were based on criteria from the European Community Respiratory Health Survey whereas those of eczema and rhinoconjunctivitis were based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age; region of residence; family history of asthma, atopic eczema, and allergic rhinitis; household income; and education.

RESULTS

Compared with never smoking, current smoking and ≥ 4 pack-years of smoking were independently positively associated with the prevalence of wheeze. There were no associations between smoking status and the prevalence of asthma, eczema, or rhinoconjunctivitis. When subjects who had never smoked were classified into four categories based on the source of ETS exposure (never, only at home, only at work, and both), exposure occurring both at home and at work was independently associated with an increased prevalence of two outcomes: wheeze and rhinoconjunctivitis. No relationships were observed between exposure to ETS and the prevalence of asthma or eczema.

CONCLUSIONS

Our results provide evidence that current smoking and ETS exposure may increase the likelihood of wheeze. The possibility of a positive association between ETS exposure and rhinoconjunctivitis was also suggested.

The prevalence of atopic dermatitis, asthma, and allergic rhinitis and the comorbidity of allergic diseases in children

OBJECTIVES

Childhood allergic diseases are a major concern because they lead to a heavy economic burden and poor quality of life. The purpose of this study was to investigate the prevalence of childhood atopic dermatitis, asthma, allergic rhinitis, and the comorbidity of allergic diseases in Seoul, Korea.

METHODS

We conducted a cross-sectional survey between May and October 2010 to evaluate the prevalence of childhood allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis, using a questionnaire from the International Study of Asthma and Allergies in Childhood group. Each questionnaire was completed by the parent or guardian of a child.

RESULTS

In the 31,201 children studied, the prevalence of atopic dermatitis symptoms in the past 12 months was 19.3% in children 0 to 3 years of age, 19.7% in children 4 to 6 years of age, 16.7% in children 7 to 9 years of age, and 14.5% in children 10 to 13 years of age (p for trend < 0.001). The prevalence of asthma in these age groups was 16.5%, 9.8%, 6.5%, and 5.4%, respectively (p for trend < 0.001). The prevalence of allergic rhinitis in these age groups was 28.5%, 38.0%, 38.5%, and 35.9%, respectively (p for trend = 0.043). The percentage of subjects with both atopic dermatitis and asthma, both asthma and allergic rhinitis, or both atopic dermatitis and allergic rhinitis was 2.5%, 4.7%, and 8.7%, respectively. The prevalence of comorbid allergic diseases decreased with age (p for trend < 0.001).

CONCLUSIONS

Our study revealed that the prevalence of some allergic diseases, such as atopic dermatitis and asthma, was relatively high in very young children and that all of the principal allergic diseases in children often co-exist.

ADAM33 genetic polymorphisms, smoking, and rhinoconjunctivitis in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

Two previous studies have demonstrated a significant relationship between ADAM33 single nucleotide polymorphisms (SNPs) and allergic rhinitis. Here, we investigated this issue in young adult Japanese women. The study included 393 women who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Controls included 767 women without rhinoconjunctivitis according to the ISAAC criteria who had not been diagnosed with allergic rhinitis by a doctor. The GC genotype of rs2787094, the CT genotype of rs628977, and the haplotype containing the rs2787094 C allele, the rs628977 T allele, the rs2853209 T allele, and the rs612709 G allele were significantly inversely associated with rhinoconjunctivitis. The AA genotype of rs2853209, the GA genotype of rs612709, and the haplotype carrying the rs2787094 G allele, the rs628977 C allele, the rs2853209 A allele, and the rs612709 G allele were significantly positively associated with rhinoconjunctivitis. A significant inverse relationship between rs628977 and rhinoconjunctivitis was demonstrated only in women who had never smoked, indicating a significant interaction between rs628977 and smoking. Our results suggest that SNPs and haplotypes in the ADAM33 gene are associated with rhinoconjunctivitis. This study is the first to demonstrate an interaction between rs628977 and smoking that affects rhinoconjunctivitis.

[Clinical phenotypes associated with selective IgA deficiency: a review of 330 cases and a proposed follow-up protocol]

Selective IgA deficiency is the most common Primary Immune Deficiency. Only a small proportion of these patients present during childhood, but this proportion increases over the years, and may be associated with an IgG subclass deficiency with increased susceptibility to respiratory and digestive tract infections. During childhood, IgA deficient patients may also refer to symptoms related to allergic and autoimmune diseases or tumours.

AIMS

To describe the relationship of selective IgA deficiency with infections, allergic diseases, autoimmune disorders and tumours. To investigate the presence of other immune disorders associated with selective IgA deficiency. To suggest a follow-up protocol for these patients.

METHODS

Retrospective study of paediatric patients (<18 years) being followed-up in the Clinical Immunology Department between 1992 and 2007, as well as laboratory records with IgA values below 50mg/L. Clinical records were reviewed (frequency and intensity of diseases associated with selective IgA deficiency) along with immunology tests performed.

RESULTS

A total of 330 paediatric patients were identified with a selective IgA deficiency: 39 (11.8%) suffered from recurrent ear infections (2 developed secondary deafness), 58 (17.5%) from recurrent upper respiratory tract infections, and 20 patients (6%) from recurrent pneumonia, 6 of whom developed secondary bronchiectasis and 2 underwent a lobectomy. A relationship with atopic disease was found in 62 (18.78%) of patients. Regarding digestive disorders, chronic diarrhoea was found in 21 (6.5%), coeliac disease in 22 (6.6%), and persistently high plasma transaminases in 3. Autoimmune manifestations were found in 38 (11.5%), juvenile chronic arthritis, type 1 diabetes, vitiligo, cytopenia, and Crohn's disease, amongst others). Tumours were identified in 5 (1.5%). An IgG sub-class deficiency was found in 5 patients (4%), and 6 patients had a confirmed deficiency in antibody production.

CONCLUSIONS

In our cohort, 56.6% of patients with IgA deficiency showed other comorbidities which were, in decreasing frequency: recurrent infections (respiratory and ear infections), allergic diseases, autoimmunity and tumours. Some patients will develop a more severe humoral defect (IgG subclass deficiency with or without antibody deficiency).

Parent-reported ISAAC written questionnaire may underestimate the prevalence of asthma in children aged 10-12 years

OBJECTIVES

The aim of the present study was to compare the validity of the International Study of Asthma and Allergies in Childhood (ISAAC) written (WQ) and audiovisual questionnaires (AVQ 3.0) in two age-groups (10-12 and 13-15 years, respectively).

METHODS

The 13-15 year olds performed the self-completed the WQ and AVQ on the same day. The 10-12 year olds performed the self-completed the AVQ and the parent-completed WQ was completed by their parents. The methacholine challenge test was conducted in 10-12 year olds from one elementary school.

RESULTS

In 10-12 year olds, the AVQ detected a generally higher prevalence of asthma symptoms than WQ. In 13-15 year olds, this was reversed. In 10-12 year olds, poor agreement was found between the parent-completed WQ and the self-reported AVQ. In 13-15 year olds, moderate agreement was found between the self-reported WQ and AVQ. Low sensitivity was found, in predicting bronchial hyper-responsiveness (BHR) for all questions of both WQ and AVQ in 10-12 year olds. However, the AVQ had slightly higher sensitivity than WQ, with the exception of wheeze ever, although it was not statistically significant.

CONCLUSION

The ISAAC AVQ may be another effective instrument for assessing the prevalence of asthma symptoms in children aged 10-12 years, whereas the parent-reported-WQ may underestimate the prevalence of asthma symptoms in this age-group.

The burden of allergic rhinitis and asthma

Asthma and allergic rhinitis are common health problems that cause major illness and disability worldwide. The prevalence of allergic rhinitis is estimated to range from 10% to 20% in the USA and Europe. Multiple factors contribute to the wide range of reported prevalence rates. These include type of prevalence rate reported (current or cumulative), study selection criteria, age of participants, differences in survey methods, varied geographic locations and socioeconomic status, any of which are significant enough to confound direct comparison between studies. There is no standard set of diagnostic criteria for allergic rhinitis. In most studies, the criteria for diagnosis are based on the subject's reporting, solely by questionnaire and rarely confirmed by skin testing. In addition, most studies focus on hay fever, leaving perennial allergic rhinitis underestimated. Sinus imaging is generally not performed and, therefore, rhinosinusitis not differentiated. Some investigators report 'current' prevalence while others report 'cumulative' or 'lifetime' prevalence. Epidemiologic studies have consistently shown that asthma and rhinitis often coexist in the same patients. The prevalence of asthma is <2% in subjects without rhinitis while it varies from 10% to 40% in patients with rhinitis. Furthermore, the majority of patients with asthma experience rhinitis, which is a factor in the risk for asthma. Despite recognition that allergic rhinitis and asthma are global health problems, there are insufficient epidemiologic data and more data are needed with regard to their etiologic risk factors and natural history. This aim of this review is to enable the reader to discuss prevalence, risk factors and prognosis of allergic rhinitis and asthma.

Respiratory diseases and associated factors: population-based study in São Paulo, 2008-2009

OBJECTIVE

To assess the prevalence of acute bronchitis, rhinitis, and sinusitis among children and adolescents and identify associated factors.

METHODS

This is a population-based, cross-sectional study. A household survey was conducted with 1,185 children and adolescents from the city of São Paulo (Southeastern Brazil), from 2008 to 2009. The participants were selected by means of probability sampling, stratified by sex and age, and by two-stage cluster sampling. For the adjusted analysis, multiple Poisson regression was used.

RESULTS

Of the respondents, 7.3% reported acute bronchitis, 22.6% rhinitis and 15.3% sinusitis. After the adjusted analysis, the following characteristics were associated with self;reported acute bronchitis: age 0 to 4 years (PR=17.86; 95%CI: 3.65;90.91), 5 to 9 years (PR=37.04; 95%CI: 8.13;166.67), 10 to 14 years (PR=20,83; 95%CI: 4.93;90.91), allergy (PR=3.12; 95%CI: 1.70;5.73), black and mixed-ethnicity (black and white) skin color (PR=2.29; 95%CI: 1.21;4.35), and living in a household with 1 to 3 rooms (PR=1.85; 95%CI: 1.17;2.94). As to self-reported rhinitis, the following characteristics were associated: age 10 to 14 years (PR=2.77; 95%CI: 1.60;4.78), 15 to 19 years (PR=2.58; 95%CI: 1.52;4.39), allergy (PR=4.32; 95%CI: 2.79;6.70), asthma (PR=2.30; 95%CI: 1.30;4.10) and living in flats (PR=1.70; 95%CI: 1.06;2.73). Concerning self-reported sinusitis, the following characteristics were associated: age 5 to 9 years (PR=2.44; 95%CI: 1.09;5.43), 10 to 14 years (PR=2.99; 95%CI: 1.36;6.58), 15 to 19 years (PR=3.62; 95%CI: 1.68;7.81), allergy (PR=2.23 (95%CI: 1.41;3.52) and obesity (PR=4.42; 95%CI: 1.56;12.50).

CONCLUSIONS

Respiratory diseases were more prevalent in population groups with defined characteristics, such as age group, self-reported diseases, type of household and obesity.

Dolichandrone platycalyx: New entomophilous pollen--A report on pollen sensitization in allergic individuals

BACKGROUND

Dolichandrone platycalyx, commonly known as Nile trumpet tree, is believed to have originated in East Africa. However, this and the variants of this tree are found in Europe, Asia, and America (California and Florida). The tree mostly grows in tropical climates, but temperate species are also found. This study was designed to evaluate the allergenicity of D. platycalyx, one of the most common entomophilous avenue trees in Karnataka state, and to determine the pollen production of D. platycalyx.

METHODS

All of the patients with allergic rhinitis and asthma attending a tertiary care center in South India during August 2007 to March 2008 underwent a detailed clinical evaluation and skin-prick testing to common allergens along with D. platycalyx. Control subjects without any symptoms of respiratory allergy also underwent skin testing. The pollen counts were determined for a mature unopened flower of D. platycalyx.

RESULTS

A total of 317 subjects with respiratory allergy and 30 controls were included in the study. A significant percentage (16.1%) of patients evaluated were observed to be sensitive to Dolichandrone pollen extract by skin-prick testing, whereas none of the control subjects were found to be sensitized. D. platycalyx was the fourth most common sensitizer after Parthenium hysterophorus, Prosopis juliflora, and Artemesia vulgaris. D. platycalyx was found to be a moderate pollen producer at 66,000 pollens/flower.

CONCLUSION

Sensitization to D. platycalyx is common in subjects with respiratory allergies. The clinical relevance of this sensitization and other entomophilous plants needs additional study.

Asthma and Rhinitis in South America: How Different They are From Other Parts of the World

Asthma and rhinitis epidemiology has wide variations around the world. The aim of this review was verify the prevalence of asthma and rhinitis in South America and report differences from other regions of the world. We reviewed studies with International Study of Asthma and Allergies in Childhood (ISAAC) methodology in South America, Phases I and III. In South America the ISAAC Phase I ranked four countries among top ten in prevalence of asthma and three countries among top ten in prevalence of rhinoconjunctivitis. ISAAC Phase III showed little changes in asthma and rhinitis prevalence in South American countries. The prevalence increases of asthma and rhinitis in South American centers indicate that the burden of both is continuing to rise, but the differences in prevalence are lessening.

Global analysis of breast feeding and risk of symptoms of asthma, rhinoconjunctivitis and eczema in 6-7 year old children: ISAAC Phase Three

BACKGROUND

In Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC), we investigated the relationship between breast feeding in infancy and symptoms of asthma, rhinoconjunctivitis and eczema in 6-7 year old children.

METHODS

Parents or guardians of 6-7 year old children completed written questionnaires on current symptoms of asthma, rhinoconjunctivitis and eczema, and on a range of possible asthma risk factors including a history of breast feeding ever. Prevalence odds ratios were estimated using logistic regression, adjusted for gender, region of the world, language, per capita gross national income, and other risk factors.

RESULTS

In all 206,453 children from 72 centres in 31 countries participated in the study. Reported breast feeding ever was not associated with current wheeze, with an odds ratio (adjusted for gender, region of the world, language, per capita gross national income, and factors encountered in infancy) of 0.99 (95% CI 0.92-1.05), current rhinoconjunctivitis (OR 1.00, 95% CI 0.93-1.08), current eczema (OR 1.05, 95% CI 0.97-1.12), or symptoms of severe asthma (OR 0.95, 95% CI 0.87-1.05). Breast feeding was however associated with a reduced risk of severe rhinoconjunctivitis (OR 0.74, 95% CI 0.59-0.94) and severe eczema (OR 0.79, 95% CI 0.66-0.95).

CONCLUSIONS

There was no consistent association between breast feeding use in the first year of life and either a history or current symptoms of wheezing, rhinoconjunctivitis or eczema in 6-7 year old children, but possibly an effect on severe symptoms of the latter two conditions.

Case-control study of IL13 polymorphisms, smoking, and rhinoconjunctivitis in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Six previous studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the IL13 gene and allergic rhinitis, but the results have been inconsistent. However, a recent meta-analysis using data from these 6 studies has shown that the A allele of IL13 SNP rs20541 was associated with an increased risk of allergic rhinitis, whereas no such relationship existed between IL13 SNP rs1800925 and allergic rhinitis. We investigated the associations between IL13 SNPs rs1800925 and rs20541 and the risk of rhinoconjunctivitis in Japanese women.

METHODS

Included were 393 cases who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Control subjects were 767 women without rhinoconjunctivitis according to the ISAAC criteria, who had also not been diagnosed with allergic rhinitis by a doctor. Adjustment was made for age, region of residence, presence of older siblings, smoking, family history of allergic rhinitis, and education.

RESULTS

Compared with the GG genotype of IL13 SNP rs20541, the AA genotype, occurring in 7.1% of control subjects, was significantly positively related to the risk of rhinoconjunctivitis: the adjusted odds ratio was 1.65 (95% confidence interval: 1.05 - 2.60). SNP rs1800925 was not associated with rhinoconjunctivitis. The haplotype comprising the rs1800925 C allele and the rs20541 A allele was significantly positively related to rhinoconjunctivitis. The multiplicative interactions between the two SNPs under study and smoking on the risk of rhinoconjunctivitis were not statistically significant. Based on the recessive model, however, the additive interaction between SNP rs1800925, but not rs20541, and smoking was significant.

CONCLUSIONS

This study suggests that the minor genotype of IL13 SNP rs20541 and the CA haplotype are significantly positively associated with the risk of rhinoconjunctivitis. In addition, a new pattern of biological interaction that affects the risk of rhinoconjunctivitis is described between SNP rs1800925 and smoking.

Overview on the pathomechanisms of allergic rhinitis

Allergic rhinitis a chronic inflammatory disease of the upper airways that has a major impact on the quality of life of patients and is a socio-economic burden. Understanding the underlying immune mechanisms is central to developing better and more targeted therapies. The inflammatory response in the nasal mucosa includes an immediate IgE-mediated mast cell response as well as a latephase response characterized by recruitment of eosinophils, basophils, and T cells expressing Th2 cytokines including interleukin (IL)-4, a switch factor for IgE synthesis, and IL-5, an eosinophil growth factor and on-going allergic inflammation. Recent advances have suggested new pathways like local synthesis of IgE, the IgE-IgE receptor mast cell cascade in on-going allergic inflammation and the epithelial expression of cytokines that regulate Th2 cytokine responses (i.e., thymic stromal lymphopoietin, IL-25, and IL-33). In this review, we briefly review the conventional pathways in the pathophysiology of allergic rhinitis and then elaborate on the recent advances in the pathophysiology of allergic rhinitis. An improved understanding of the immune mechanisms of allergic rhinitis can provide a better insight on novel therapeutic targets.

Organochlorine concentrations in breast milk and prevalence of allergic disorders in Japanese women

Persistent organic pollutants have been shown to have immunomodulating effects in humans. However, epidemiological evidence regarding the relationships between organochlorine compound exposure and allergic disorders coming from studies of children has been limited and inconsistent. The current cross-sectional study examined the associations between the concentrations of β-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (DDE), and trans-nonachlordane in breast milk and the prevalence of allergic disorders in 124 adult Japanese women. The definition of wheeze and asthma was based on criteria from the European Community Respiratory Health Survey whereas that of eczema and rhinoconjunctivitis was based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, smoking, family history of allergic disorders, and education. The prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12 months were 9.7%, 4.8%, 13.7%, and 29.8%, respectively. The median concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk were 28.3, 7.0, 71.6, and 23.9 ng g(-1) lipid, respectively (range, 4.5-253, 2.1-14.5, 7.5-362, and 1.8-130 ng g(-1) lipid, respectively). When the exposures were treated as continuous variables, no significant associations were found between concentrations of HCB, β-HCH, p,p'-DDE, or trans-nonachlordane and the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis. Our results suggest that concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk are not evidently associated with the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis in young female Japanese adults.

Prediction of the incidence and persistence of allergic rhinitis in adolescence: a prospective cohort study

BACKGROUND

Predictive models have rarely been used in allergy research and practice. However, they might support physicians in advising patients.

OBJECTIVE

The aim of this study was to create predictive models for the incidence and persistence of allergic rhinitis (AR) during adolescence.

METHODS

A prospective population-based cohort study was conducted starting at age 9 to 11 years. Potential risk factors for atopic diseases obtained at baseline in 2810 subjects were used to create predictive logistic regression models for the incidence and persistence of physician-diagnosed AR with current symptoms at age 15 to 18 years.

RESULTS

Positive skin prick test responses to outdoor allergens at baseline were the most important determinant for both the incidence and persistence of AR until follow-up. For the incidence of AR, positive skin prick test responses to indoor allergens, parental history of asthma, female sex, and not having been breast-fed exclusively for 2 or more months were additional statistically significant independent risk factors. Depending on the number of risk factors present, the probability of the incidence of AR increased from 2% (no risk factors present) to 72% (full model; 95% CI, 58% to 85%). The probability of persistence of AR ranged from 33% (no risk factors present) to 83% (full model; 95% CI, 70% to 97%).

CONCLUSION

The course of AR over puberty can be predicted using risk factors that are easy to determine in childhood. Sensitization to outdoor allergens seems to play a much greater role for disease development than sensitization to indoor allergens. This might help pediatricians in advising patients.

Correlation of nasal smear eosinophilia with class of allergic rhinitis

We correlated the grade of nasal smear eosinophilia with severity of allergic rhinitis, in 50 children in a cross sectional study conducted at a tertiary care referral hospital, between August 2007 to July 2009. The grade of nasal smear eosinophilia correlated well with increasing severity of allergic rhinitis (P<0.001)(r=0.83).

Prevalence of asthma and allergies in 13- to 14-year-old adolescents and the frequency of risk factors in carriers of current asthma in Taubaté, São Paulo, Brazil

BACKGROUND

The objectives of this study were to determine the prevalence of asthma and allergies in 13- to 14-year-old adolescents in the city of Taubaté, São Paulo, Brazil using the INTERNATIONAL STUDY OF ASTHMA AND ALLERGIES IN CHILDHOOD (ISAAC) questionnaire and to describe the presence of risk factors in current asthma carriers.

METHODS

We used a cross-sectional study involving 920 adolescents who completed the ISAAC questionnaire and answered additional questions regarding smoking and the presence of pets and/or insects at home.

RESULTS

The mean prevalence rate of "current asthma" was 15.3% and "asthma ever" was 6.8%. The mean prevalence rate of "current rhinitis" was 36.6% and "rhinitis ever" 37.6%. The prevalence of "eczema ever" was 16.2%. The frequency of active smoking was low (0.7%), and the presence of indoor animals (34%) and of insects (55.1%) was high.

CONCLUSIONS

The prevalence of "current asthma" was twice as high as that of "asthma ever". There was no association between risk factors studied and current asthma.

Close collaboration between academia, industry and drug regulators is required in the development of allergen products for specific immunotherapy in children

Modification of the response to allergens at an early stage and thereby of the natural history of a respiratory allergic disease by preventing disease progression would constitute the key benefit of specific immunotherapy (SIT) in children. However, although allergen products for SIT have been on the market on a named-patient basis for many years, long-term efficacy, the optimal duration of the treatment and the optimal dosage have not been sufficiently elaborated until now. The enactment of the Therapy Allergen Ordinance in Germany mandates that allergen products for SIT of the most prevalent allergies must submit an application for marketing authorization to the German authorities. In line with the European Paediatric Regulation, decisions by the European Medicines Agency on agreed paediatric investigation plans must be included in these applications. These regulatory requirements provide a unique opportunity to fill the gap in knowledge concerning the benefits of SIT for children and to obtain the data needed to support evidence-based authorization of allergen products for immunotherapy. This goal can only be achieved through close cooperation between academia, drug regulators and industry as well as parent/patient organizations.

Sibling number and prevalence of allergic disorders in pregnant Japanese women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Although an inverse relationship between number of siblings and likelihood of allergic disorders has been shown in many epidemiological studies, the biological mechanism underlying this phenomenon has not yet been identified. There is no epidemiological research regarding the sibling effect on allergic disorders in Japanese adults. The current cross-sectional study examined the relationship between number of siblings and prevalence of allergic disorders among adult women in Japan.

METHODS

Subjects were 1745 pregnant women. This study was based on questionnaire data. The definitions of wheeze and asthma were based on criteria from the European Community Respiratory Health Survey whereas those of eczema and rhinoconjunctivitis were based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, region of residence, pack-years of smoking, secondhand smoke exposure at home and at work, family history of asthma, atopic eczema, and allergic rhinitis, household income, and education.

RESULTS

The prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12 months were 10.4%, 5.5%, 13.0%, and 25.9%, respectively. A significant inverse exposure-response relationship was observed between the number of older siblings and rhinoconjunctivitis, but not wheeze, asthma, or eczema (P for trend=0.03); however, the adjusted odds ratio (OR) for having 2 or more older siblings was not significant although the adjusted OR for having 1 older sibling was statistically significant (adjusted OR=0.71 [95% CI: 0.56-0.91]). Number of total siblings and number of younger siblings were not related to wheeze, asthma, eczema, or rhinoconjunctivitis.

CONCLUSIONS

This study found a significant inverse relationship between the number of older siblings and the prevalence of rhinoconjunctivitis among pregnant Japanese women. Our findings are likely to support the intrauterine programming hypothesis; however, we could not rule out the hygiene hypothesis.

Immune dysregulation after cardiothoracic surgery and incidental thymectomy: maintenance of regulatory T cells despite impaired thymopoiesis

Thymectomy is performed in infants during cardiothoracic surgery leaving many patients with reduced thympopoiesis. An association between immune disorders and regulatory T cells (Treg) after incidental thymectomy has not been investigated. Questionnaires soliciting symptoms of atopic or autoimmune disease and biomarkers were measured in children and adults with congenital heart disease and either reduced or preserved thymopoiesis. Tregs were examined. Atopic or autoimmune-like symptoms and elevated anti-dsDNA antibodies were common after surgery in individuals with low thymopoiesis. Total Treg number and function were maintained but with fewer naïve Treg. TCR spectratypes were similar to other memory T cells. These data suggest that thymectomy does not reduce total Treg number but homeostasis is affected with reduced naïve Treg. Prevalence of autoimmune or atopic symptoms after surgery is not associated with total number or proportion of Tregs but appears to be due to otherwise unknown factors that may include altered Treg homeostasis.

Early protective and risk factors for allergic rhinitis at age 4½ yr

Allergic heredity plays a major role in the development of allergic rhinitis. In addition the introduction of food may influence the risk of subsequent allergic disease. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at preschool age. Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003 and 8,176 families (50% of the birth cohort) were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4½ yr of age. The response rate at 4½ yr was 4,496, i.e. 83% of the 5,398 questionnaires distributed at 4½ yr. At 4½ yr of age, 5.5% reported symptoms of allergic rhinitis during the last year. In the multivariate analysis, independent risk factors for allergic rhinitis were: allergic sensitisation to food allergens at 4½ yr (OR 10.21; 95% confidence interval 4.22-24.73), recurrent wheeze at 4½ yr (3.33; 1.56-7.10), doctor-diagnosed eczema at 4½ yr (2.72; 1.62-4.55), parental rhinitis (2.21; 1.39-3.53), eczema first year (1.97; 1.19-3.26) and male gender (1.82; 1.13-2.94). The risk was reduced with fish introduction before 9 months (0.49; 0.29-0.82). In conclusion, we found that previous and present allergic disease, heredity and male gender increased the risk of allergic rhinitis at 4½ yr of age. The introduction of fish before the age of 9 months reduced the risk.

Polyunsaturated fatty acid intake and prevalence of eczema and rhinoconjunctivitis in Japanese children: the Ryukyus Child Health Study

Background

The recent increase in the prevalence of allergic disorders might be a consequence of increased intake of n-6 polyunsaturated fatty acids (PUFAs) and reduced intake of n-3 PUFAs. The current cross-sectional study examined the association between intake levels and the prevalence of eczema and rhinoconjunctivitis in Japanese children.

Methods

Subjects were 23,388 schoolchildren aged 6-15 years residing in Okinawa. The presence of eczema and/or rhinoconjunctivitis was determined according to the criteria of the International Study of Asthma and Allergies in Childhood. A brief diet history questionnaire for children and adolescents was administered to acquire information on dietary factors. Adjustment was made for age, sex, residential municipality, number of siblings, smoking in the household, body mass index, paternal and maternal history of allergic diseases, and paternal and maternal educational level.

Results

The prevalences of eczema and rhinoconjunctivitis in the previous 12 months were 7.0% and 8.0%, respectively. Consumption of PUFAs, n-3 PUFAs, α-linolenic acid, n-6 PUFAs, and linoleic acid was positively associated with the prevalence of eczema: the adjusted odds ratios (ORs) between extreme quintiles (95% confidence intervals [CIs], P for trend) were 1.26 (1.07-1.48, 0.04), 1.31 (1.11-1.54, 0.009), 1.31 (1.12-1.55, 0.003), 1.26 (1.07-1.48, 0.01), and 1.27 (1.08-1.49, 0.01), respectively. Arachidonic acid intake was independently inversely related to eczema: the adjusted OR between extreme quintiles was 0.81 (0.69-0.95, 0.0008). Eczema was not associated with eicosapentaenoic or docosahexaenoic acid intake, or with the ratio of n-3 to n-6 PUFA intake. Only arachidonic acid intake was statistically significantly related to the prevalence of rhinoconjunctivitis, showing a clear inverse linear trend: the adjusted OR between extreme quintiles was 0.86 (0.74-0.997, 0.03).

Conclusions

Consumption of n-3 and n-6 PUFAs, especially α-linolenic acid and linoleic acid, may be positively associated with eczema. Arachidonic acid intake may be inversely related to eczema and rhinoconjunctivitis.

Correlation of worldwide incidence of type 1 diabetes (DiaMond) with prevalence of asthma and atopic eczema (ISAAC)

INTRODUCTION

Environmental factors play a role in pathogenesis of both type 1 diabetes and atopic disease but they remain incompletely understood. T cell-mediated responses primarily of the T helper type 1 (Th1) are involved in type 1 diabetes while T helper type 2 (Th2) responses favour allergic disease. This TH 1/TH 2 paradigm is currently the source of much controversy in various studies.

OBJECTIVE

The aim of the study was to compare the reported country incidence of type 1 diabetes with the prevalence of atopic disease.

METHODS

The prevalence of wheeze, rhinitis, rhinoconjunctivitis and atopic eczema in the preceding 12 months in the 13- to 14-year-old age group was taken from The International Study of Asthma and Allergies in Childhood phase 1 study. These were compared to the age specific incidence of type 1 diabetes in children per 100 000 per year obtained from the Diabetes Mondiale Project Group study from those countries participating in both studies. Data collected from these 31 countries together with latitude was analysed using a Pearson correlation and significance analysis. A multiple regression analysis determined the confounding effect of latitude.

RESULTS

The incidence of type 1 diabetes was found to have a positive correlation with both wheezing (P = 0.009) and atopic eczema (P < 0.01). There was a no correlation between the incidence of type 1 diabetes and the prevalance of rhinitis (r = 0.02, P = 0.88) or of rhinoconjunctivitis (r = 0.026, P = 0.88). Latitude correlated negatively with type 1 diabetes and positively with rhinitis and rhinoconjnctuvits; it was not significantly correlated with wheeze or eczema. Regression analysis showed that latitude is a significant confounding factor in the correlation of rhinitis (P value < 0.0008) and rhinoconjunctivitis (P value < 0.0003) with diabetes.

CONCLUSIONS

The study suggests that common environmental and/or genetic factors predispose to type 1 diabetes, wheezing and atopic eczema while factors predisposing to rhinitis and rhinoconjunctivitis appear to be distinct from those predisposing to type 1 diabetes.

Outdoor air pollution and asthma in children

BACKGROUND

Asthma, a chronic inflammatory disease of the airways, is associated with reversible airway obstruction and hyperresponsiveness to triggers; clinical symptoms include wheezing, episodic cough, shortness of breath, and increased mucous production. Ambient or outdoor environmental exposure to ozone, particulate matter, sulfur dioxide, and nitrogen oxides has been well documented to exacerbate asthma. Children appear to be most vulnerable to the harmful effects of ambient air pollutants. As their lungs are not completely developed, children may experience greater exposure to environmental pollutants than adults and the higher doses of varied composition may remain in their lungs for a greater duration. Altogether, the negative effects of air pollutants on pulmonary function place children at a greater risk of air pollutant-induced exacerbation of asthma for the duration of their lives.

OBJECTIVES

The aim of this review was to assess recently published literature regarding the influence of air pollution on asthma in children.

METHODS

For this work, we reviewed articles found in PubMed using the key words "outdoor air pollution, asthma, and children" which were published between 2006 and 2009. Only those articles that had a full version available in PubMed were analyzed.

RESULTS

We reviewed studies published between 2006 and 2009 examining the effect of outdoor air pollution on asthma in children. In total, we evaluated 25 articles; of these, 9 were published in 2006, 3 in 2007, 8 in 2008, and 5 in 2009. Of these 25 studies, 1 was a clinical trial, 6 were cross-sectional, 4 were case-control (2 with a case-crossover design), 12 were cohort prospective, and 2 were cohort retrospective studies with varied follow-up times ranging from 10 days to 7 years. The ages of children also differed, ranging from birth to 18 years of age.

CONCLUSIONS

All studies reviewed in this work indicate that outdoor air pollution affects the appearance and exacerbation of asthma in children. Although these findings are of great interest, the limitations of noted works make future investigations of the effect of air pollution on asthma in children essential.

Prevalence of allergic diseases in a sample of Taif citizens assessed by an original Arabic questionnaire (phase I) A pioneer study in Saudi Arabia

BACKGROUND

In recent decades, the prevalence of allergic diseases has markedly increased worldwide; however, there are still many cases which remain undiagnosed. Epidemiological studies have the potential to elucidate the prevalence and risk factors for these diseases.

OBJECTIVES

This study aimed at evaluating the capability of a new original non-translated questionnaire in Arabic language to determine the prevalence and severity of these diseases in a sample from Taif citizens. Thus, it could provide a framework as an initial step towards accomplishing the first national questionnaire-based survey study determining the actual prevalence of various allergic diseases in Saudi Arabia.

METHODS

A detailed seven-section questionnaire including 143 closed questions covering almost all of the usual and unusual symptoms of various allergic diseases, in Arabic language, was handed out to 1050 subjects, from whom 877 (83.52%) questionnaires were completed; however, 23 questionnaires were discarded as they were not accurately filled in. Thus, 854 (81.33%) were enrolled in this study.

RESULTS

Urticaria, allergic rhinitis with or without other co-morbidities, and atopic dermatitis were the most prevalent allergic morbidities, however, other allergic diseases could be diagnosed by the aid of the questionnaire. Likelihood ratio-evidenced agreement between diagnosis reached by the questionnaire and that reached by doctor occurred in 50 sample cases (p<0.0001).

CONCLUSIONS

The questionnaire proved its capability in aiding the diagnosis of various allergic morbidities. It evidenced a high prevalence of allergic diseases in Taif city. This is an important health issue which requires strategic application of primary health care facilities to achieve adequate control.

Prevalence of symptoms of asthma, rhinitis and atopic eczema among students between 6 and 7 years of age in the city of Londrina, Brazil

OBJECTIVE

To determine the prevalence of symptoms of asthma, rhinitis and atopic eczema among students between 6 and 7 years of age in the city of Londrina, Brazil.

METHODS

A population-based study using the International Study of Asthma and Allergies in Childhood (ISAAC) standardized questionnaire (asthma, rhinitis and atopic eczema modules), validated for use in Brazil, in public school students between 6 and 7 years of age.

RESULTS

Of the 3,963 questionnaires retrieved, 3,600 (90.8%) were appropriately completed and were used in the analysis. The prevalence of symptoms of asthma, rhinitis and atopic eczema in the last 12 months was 22.0%, 27.3% and 9.6%, respectively. The prevalence of physician-diagnosed asthma, rhinitis and atopic eczema was 10.4%, 23.4% and 11.4%, respectively. The prevalence of rhinoconjunctivitis and flexural eczema was 13.6% and 6.6%, respectively. Although symptoms of asthma and rhinitis were more common in males than in females, no gender difference was found regarding atopic eczema symptoms.

CONCLUSIONS

The prevalence of symptoms of asthma, rhinitis and atopic eczema in our sample was within the range found at the facilities that participated in phases I and III of the ISAAC in Brazil. The low prevalence of physician-diagnosed asthma suggests that asthma continues to be underdiagnosed.

Eczema in early life: genetics, the skin barrier, and lessons learned from birth cohort studies

Eczema is a chronic inflammatory disorder of the skin that affects up to 30% of children. It often afflicts infants in the first few months of life and can be the first indicator of the atopic march. Recent results from birth cohort studies have uncovered novel information regarding genetic and environmental factors that promote the development of eczema. Birth cohort studies provide an optimal study design to elucidate these associations and prospectively track longitudinal data including exposure assessment and health outcomes from birth into early life and childhood. This is especially relevant for eczema given the age specific emergence of this disease. In this review, we will provide a general overview of pediatric eczema and discuss the important findings in the literature with respect to genetics and environmental exposures, highlighting those derived from birth cohort studies. Additionally, we will review how these relate to the atopic march, the hygiene hypothesis and the integrity of the skin barrier.

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.

Temporal relationship of allergic rhinitis with asthma and other co-morbidities in a Mediterranean country: a retrospective study in a tertiary reference allergy clinic

BACKGROUND

Allergic rhinitis is a global health problem which causes major illness and represents a risk factor for asthma. The primary aim of the study was to record the clinical pattern of allergic rhinitis and its temporal relation with asthma in a Greek population.

METHODS

Three-hundred and sixteen subjects with documented diagnosis of allergic rhinitis in a two-year period were included in this study. All participants completed a standardised questionnaire with full retrospective epidemiological data for rhinitis; in addition, serum IgE measurement and skin prick tests with 22 common inhalant allergens were carried out, while spirometry was performed in subjects with self-reported or doctor-diagnosed asthma. All subjects with at least one positive skin test were included in study analysis.

RESULTS

One-hundred and sixty five out of 316 patients (49.1%) stated self reported-asthma while in 63/316 (19.9%) asthma was documented with spirometry. One hundred out of 165 (60.6%) had rhinitis as first clinical manifestation while in 24/165 (14.5%) asthma symptoms appeared first; the remaining 31/165 (24.9%) reported simultaneous onset of upper and lower airways' symptoms. About 68.5% were sensitised to seasonal allergens exclusively, while 50% were sensitised to ≥ 1 of Parietaria, grasses sp., Olea eur. The duration of rhinitis in the subpopulation of patients with self-reported asthma (n=165) was significantly higher compared with non-asthmatics (mean=3.22 years, p<0.001). Survival analysis for the estimation of asthma onset showed that the mean time interval with rhinitis only is 16.6 years (median 12 years, incidence 0.0596).

CONCLUSIONS

The unique environmental conditions and the aerobiology of each area clearly affect the clinical features of respiratory allergy.

Exhaled nitric oxide, susceptibility and new-onset asthma in the Children's Health Study

A substantial body of evidence suggests an aetiological role of inflammation, and oxidative and nitrosative stress in asthma pathogenesis. Exhaled nitric oxide fraction (F(eNO)) may provide a noninvasive marker of oxidative and nitrosative stress, and aspects of airway inflammation. We examined whether children with elevated F(eNO) are at increased risk for new-onset asthma. We prospectively followed 2,206 asthma-free children (age 7-10 yrs) who participated in the Children's Health Study. We measured F(eNO) and followed these children for 3 yrs to ascertain incident asthma cases. Cox proportional hazard models were fitted to examine the association between F(eNO) and new-onset asthma. We found that F(eNO) was associated with increased risk of new-onset asthma. Children in the highest F(eNO) quartile had more than a two-fold increased risk of new-onset asthma compared to those with the lowest quartile (hazard ratio 2.1, 95% CI 1.3-3.5). This effect did not vary with the child's history of respiratory allergic symptoms. However, the effect of elevated F(eNO) on new-onset asthma was most apparent among those without a parental history of asthma. Our results indicate that children with elevated F(eNO) are at increased risk for new-onset asthma, especially if they have no parental history of asthma.

Prevalence and risk factors for allergic rhinitis in primary schoolchildren in Budapest

OBJECTIVE

There is growing evidence that the prevalence of allergic diseases is increasing, especially among children. The aim of this study was to evaluate the incidence and risk factors of allergic rhinitis in 6-12-year-old schoolchildren in Budapest.

METHODS

A total of 6335 children aged between 6 and 12 years attending 21 randomly selected primary schools in Budapest were surveyed in September 2007 by using a questionnaire consisting in part of questions compiled by the International Study of Asthma and Allergies in Childhood and in part of questions based on our own experience.

RESULTS

3933 of the questionnaires (1976 M/1957 F) were appropriately completed by the parents. The prevalence of current allergic rhinitis was 14.9% (n=530), that of physician-diagnosed allergic rhinitis was 11.6% (n=413), and that of cumulative allergic rhinitis was 26.5% (n=943). Male gender (p<0.001), family history of atopy (p<0.001), eczema (p<0.001), urticaria (p<0.001), itchy-watery eyes (p<0.001), coughing (p<0.001), wheezing (p<0.001), a hearing impairment (p<0.001), itching of the palate (p<0.001), frequent upper airway infection (p<0.001), frequent rhinosinusitis (p<0.001), a history of tonsillectomy (p<0.01), a history of adenoidectomy (p<0.001), antibiotics given in the first year of life (p<0.001), paracetamol given in the first year of life (p<0.001), living in a green area (p<0.001), the consumption of soft drinks containing preservatives or colourants (p<0.04), feather bedding (p<0.01), living in a house made of concrete (p<0.001), living not far from an air-polluting factory or mine (p<0.001), and long-lasting disease before the appearance of the allergy (p<0.001) were all significant factors involving an increased risk of allergic rhinitis symptoms. The frequent consumption of tomatoes, nuts, margarine and butter significantly affected the cumulative allergic rhinitis prevalence.

RESULTS

Overall, the 12-month prevalence of allergic rhinitis in these 6-12-year-old children in Budapest was 14.9%, which is higher than reported from other European countries. Our findings differ from those on other cohorts in that exposure to ragweed and to indoor environmental factors in concrete housing estates in Budapest may be of particular importance as concerns allergic sensitization.

Exposure to animals and risk of oligoarticular juvenile idiopathic arthritis: a multicenter case-control study

Background

An inverse association between early contact with microbial compounds and respiratory allergies is well established. The protective effect of infant contact with animals was also shown for inflammatory bowel disease (IBD) and systemic lupus erythematosus (SLE). We aimed to test the association between animal contact in infancy and oligoarticular juvenile idiopathic arthritis (OA JIA).

Methods

Parents of children with OA JIA registered at the Hospital for Pediatric Rheumatology in Garmisch-Partenkirchen were asked to complete a questionnaire. Children who underwent strabismus surgery at six referral centers for ophthalmology served as controls. Children age 6 to 18 years born in Germany without malformations were included (238 cases; response 89% and 832 controls; response 86%). Data were analyzed using logistic regression models after adjusting for potential confounders.

Results

Neither place of living (urban vs. rural area), living on a farm, nor regular farm animal (adjusted odds ratio 0.79; 95% confidence interval 0.42-1.47) or pet contact (0.79; 0.55-1.14) during infancy were clearly related to case status. Allergic rhinitis was inversely related to OA JIA (0.57; 0.34-0.95).

Neither place of living (urban vs. rural area), living on a farm, nor regular farm animal (adjusted odds ratio 0.79; 95% confidence interval 0.42-1.47) or pet contact (0.79; 0.55-1.14) during infancy were related to case status. Allergic rhinitis was inversely related to OA JIA (0.57; 0.34-0.95).

Conclusions

Contact with farm environments in infancy might not be associated with OA JIA. This finding is consistent with previous findings for diabetes mellitus type 1 but contradicts results for IBD and SLE.

Is the prevalence of asthma declining? Systematic review of epidemiological studies

Asthma prevalence has increased very considerably in recent decades such that it is now one of the commonest chronic disorders in the world. Recent evidence from epidemiological studies, however, suggests that the prevalence of asthma may now be declining in many parts of the world, which, if true is important for health service planning and also because this offers the possibility of generating and testing new aetiological hypotheses. Our objective was to determine whether the prevalence of asthma is declining worldwide. We undertook a systematic search of EMBASE, Medline, Web of Science and Google Scholar, for high quality reports of cohort studies, repeat cross-sectional studies and analyses of routine healthcare datasets to examine international trends in asthma prevalence in children and adults for the period 1990-2008. There were 48 full reports of studies that satisfied our inclusion criteria. The large volume of data identified clearly indicate that there are, at present, no overall signs of a declining trend in asthma prevalence; on the contrary, asthma prevalence is in many parts of the world still increasing. The reductions in emergency healthcare utilization being reported in some economically developed countries most probably reflect improvements in quality of care. There remain major gaps in the literature on asthma trends in relation to Africa and parts of Asia. There is no overall global downward trend in the prevalence of asthma. Healthcare planners will for the foreseeable future, therefore, need to continue with high levels of anticipated expenditure in relation to provision of asthma care.