Modest increase in seasonal allergic rhinitis and eczema over 8 years among Estonian schoolchildren

We studied time trends in the prevalence of asthma and allergic diseases in Estonian children born before and after the collapse of the Soviet Union, as this event markedly altered the lifestyle in Estonia. Two identical cross-sectional studies were performed as part of phase I and phase III of the International Study of Asthma and Allergies in Childhood (ISAAC). Children, aged 6-7 yr (n = 3070 in 1993-94 and 2383 in 2001-02) and 13-14 yr (n = 3476 and 3576, respectively), completed ISAAC core-written questionnaires, and 13-14-yr olds (n = 3427 and 3259, respectively) also video questionnaires. The prevalence of respiratory symptoms was mostly similar in the two studies. Despite this, the prevalence of diagnosed asthma increased. This was probably due to modified diagnostic criteria and increased awareness. Furthermore, the prevalence of rhinitis during the pollen season increased, e.g., rhinitis in May from 1.7% to 3.5%; sex-adjusted prevalence odds ratio (POR) 2.09 (95% confidence interval 1.47-2.96) in 6-7-yr olds, and from 2.6% to 5.5%; POR 2.22 (1.72-2.87) in 13-14-yr olds. The prevalence of flexural dermatitis also increased from 12.0% to 13.5%; POR 1.20 (1.02-1.41) in 6-7-yr olds, and from 7.7% to 9.4%; POR 1.26 (1.07-1.50) in 13-14-yr olds. The increase was similar in children born before and after the regaining of Estonian independence, indicating that the influence of factors related to a Western lifestyle and affecting the prevalence of allergic symptoms is not restricted to infancy, but may be operative throughout childhood.     

High prevalence of allergic diseases and sensitization in a low allergen country

BACKGROUND: The prevalence of adult atopic diseases in Iceland is lower than in other West European countries, despite an affluent lifestyle, but limited data are available on children. The main aim of this study was to investigate the prevalence of atopic diseases and sensitivity to common allergens in 10- to 11-year-old Icelandic schoolchildren as part of phase II of the International Study of Asthma and Allergies in Children (ISAAC). METHODS: Nine hundred and forty-six children and their parents answered a questionnaire about atopic diseases. Skin prick tests with six allergens were performed on 773 children and they were examined for signs of atopic dermatitis (AD). RESULTS: The 12-month prevalence of allergic rhinoconjunctivitis and asthma was 11.5% and 8.9% respectively. The reported prevalence of AD was 27%, but only 9.2% had signs when inspected. A positive skin prick test (SPT) was found in 24.4% of the children, that is 18.8% to grass, 12.9% to cat, 3.6% to trees, 3.0% to Dermatophagoides pteronyssinus, 1.4% to D. farinae and 0.5% to Alternaria. CONCLUSION: The high prevalence of atopic diseases in children at 10-11 years is surprising, as the prevalence in adults is low in Iceland. The findings resemble those in developing countries. Iceland has had an affluent lifestyle for a considerable time, but the absence of dust mites, low pet ownership and relatively low pollen counts in the country raise doubts about the role of exposure levels in the development of sensitization and atopic diseases.     

The changing prevalence of asthma, allergic rhinitis and atopic eczema in African adolescents from 1995 to 2002

The prevalence of asthma and allergic disease in children has been increasing in developed countries, but there is little information on these trends in Africa. The aim of this study was to assess time trends in the symptoms of asthma, allergic rhinitis, and atopic eczema among South African adolescents. The study was carried out by comparing cross-sectional data from two International Study of Asthma and Allergies in Childhood (ISAAC phase I and phase III) questionnaire based surveys conducted 7 yr apart of self-reported symptoms in 13- to 14-yr-old adolescents. In both surveys, schools in the same geographical area in Cape Town, South Africa, were randomly selected. A school-based sample of 5178 (in 1995) and 5037 (in 2002) pupils participated. The 12-month prevalence of wheezing (16% vs. 20.3%), exercise-induced wheeze (21.5% vs. 32.5%), nocturnal cough (23.6% vs. 36.6%), sleep disturbance due to wheeze (9.6% vs. 16%), or severe wheeze (5.1% vs. 7.8%) increased significantly, as measured by the written questionnaire. A rise in asthma symptoms was confirmed by the video questionnaire responses, in which the 12-month prevalence of wheezing (6.5% vs.11.2%), exercise-induced wheeze (11.5% vs. 13.9%), nocturnal wheeze (3.9% vs. 5.3%), nocturnal cough (11.6% vs. 19.2%), or severe wheeze (5% vs. 7%) also increased significantly. There was a small increase in the percentage of children diagnosed with asthma from 1995 to 2002 (13.1% vs. 14.4%), this was not significant. The 12-month prevalence of symptoms of allergic rhinitis (30.4% vs. 38.5%), rhinoconjunctivitis (17.6% vs. 24.3%) and eczema (11.8% vs. 19.4%) also increased significantly. An increase in the prevalence of allergic symptoms occurred in girls and boys. Limitation of daily activity from nasal symptoms (22.3% vs. 37.8%) and sleep disturbance because of eczema (8.4% vs. 15.7%) increasingly affected quality of life on the quality of life. Symptoms of asthma, allergic rhinitis and atopic eczema in adolescents have increased over the past 7 yr in this geographical area. Allergic diseases are common in this group of adolescents and increasingly impair their quality of life.     

Disparate geographic prevalences of asthma,allergic rhinoconjunctivitis and atopic eczema among adolescents in five Canadian cities

Wang H‐Y, Pizzichini MMM, Becker AB, Duncan JM, Ferguson AC, Greene JM, Rennie DC, Senthilselvan A, Taylor BW, Sears MR. Disparate geographic prevalences of asthma, allergic rhinoconjunctivitis and atopic eczema among adolescents in five Canadian cities.
Pediatr Allergy Immunol 2010: 21: 867–877.
© 2010 John Wiley & Sons A/S To assess concordance of prevalence rates of asthma, allergic rhinoconjunctivitis and atopic eczema symptoms among adolescents in five Canadian cities. The International Study of Asthma and Allergies in Childhood Phase 3 written questionnaires were answered by 8334 adolescents aged 13 to 14 in Vancouver, Saskatoon, Winnipeg, Hamilton and Halifax, Canada. Prevalence rates of current symptoms ranged from 13.7–33.0% for wheezing, 14.6–22.6% for allergic rhinoconjunctivitis and 8.2–10.4% for atopic eczema. Using Hamilton as reference, the prevalence of wheezing was significantly higher in Halifax (OR = 1.58; 95% CI 1.36–1.84) and Saskatoon (1.27; 1.07–1.50) and significantly lower in Vancouver (0.51; 0.44–0.59). In contrast, allergic rhinoconjunctivitis was significantly more prevalent in Winnipeg (1.39; 1.16–1.68) and Halifax (1.36; 1.14–1.61) and trended lower in Saskatoon (0.81; 0.66–1.00). Atopic eczema was significantly more prevalent in Winnipeg (1.31; 1.01–1.69) and Vancouver (1.28; 1.04–1.58). Multivariable logistic regression analyses showed the region of residence, being born in Canada, recent use of acetaminophen and heavy exposure to traffic exhaust were significantly associated with all three allergic conditions, while obesity and having two or more smokers at home was only associated with increased risk for wheezing. Chinese ethnicity decreased that risk. Among five Canadian centres, the highest prevalence rates of allergic rhinoconjunctivitis or atopic eczema were not observed in the same regions as the highest prevalence rates of wheezing. This disparity in regional variations in the prevalence rates suggests dissimilar risk factors for the development or expression of wheezing (asthma), allergic rhinoconjunctivitis and atopic eczema.     

Prevalence of childhood asthma, allergic rhinitis and eczema in Urumqi and Beijing

OBJECTIVE: To assess the prevalence of asthma and other allergies in children in Urumqi and Beijing, compared with that in Hong Kong. METHODS: A total of 7754 primary school students were randomly selected to participate in the study. Data were collected in 1995-96 using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol for 6- and 7-year-olds. The study design and data quality assurance in all aspects followed the protocol, including the double entry of data. RESULTS: The questionnaire response rate was high (98.9%). Beijing children reported significantly more asthma than those living in Urumqi in three categories: wheezing or whistling in the chest in the past year (6.0%, 95% confidence interval (CI): 5.1-6.9% vs 2.9%, 2.3-3.5%, P < 0.001), sleeping disturbed due to wheezing (1.3%, 0.9-1.7% vs 0.6%, 0.3-0.9%, P < 0. 03) and having experienced asthma ever (10.7%, 9.6-11.8% vs 7.6%, 6. 6-8.6%, P < 0.001). The prevalence of allergic rhinitis (30.0% vs 31. 1% estimated as 12-month nasal symptoms in Beijing and Urumqi, respectively) and eczema (2.8% vs 2.0% recorded as 12-month itchy rash) in the two cities were not significantly different. A similar study was also performed in Hong Kong in 1995 using the same ISAAC protocol. The children in Urumqi and Beijing had fewer (P < 0.05) allergic symptoms compared to those living in Hong Kong (n = 3618). The 12-month prevalence of wheezing, nasal symptoms and itchy rash found in Hong Kong were 9.2% (95% CI: 8.2-10.2%), 35.1% (33.5-36.7%) and 4.2% (3.5-4.9%), respectively. CONCLUSION:: Urumqi, Beijing and Hong Kong represent communities at different stages of westernization and the results from these three cities reflect a worldwide trend for an increasing prevalence of allergies along with westernization. These three cities could assist in identifying risk factors involved in the increase in asthma, allergic rhinitis and eczema.     

The determinants of dust mite allergen and its relationship to the prevalence of symptoms of asthma in the Asia-Pacific region

The role that house dust mites play in the primary causation of asthma is controversial. Approximately thirty-six 10-yr-old children in each of 10 centres in the Asia-Pacific region participated. Researchers collected dust from mattresses and living room floors using standardized procedures. Der p1 and Der f1 were analysed using a double monoclonal antibody enzyme-linked immunosorbent assay. Geometric mean allergen levels were calculated for each centre. An ecological analysis was conducted to show the regression of the geometric mean allergen level, using the highest household level, against asthma symptom and severity prevalence data from the International Study of Asthma and Allergies in Childhood, Phase I. Among children aged 13–14 yr, the change in asthma symptom prevalence was associated with per unit change in Der p 1  μ g/g (1.08, 95% CI 0.10–2.06) and Der 1  μ g/g (Der p1 + Der f1) (0.64, 95% CI 0.02–1.26). The change in having four or more attacks of asthma in the last 12 months was associated with per unit change in Der p 1  μ g/g (0.29, 95% CI −0.02 to 0.60) and Der 1  μ g/g (0.20, 95% CI 0.01–0.38). There was no effect for total Der p1 or Der f1 (total or μ g/g). Among children aged 6–7 yr, neither allergen was related to symptoms or severity prevalence. While our findings suggest that Dermatophagoides pteronyssinus may have a role in the primary causation of asthma, the complexity of this association reinforces the need for prospective studies.     

Recent advances in epidemiology and prevention of atopic eczema

Atopic dermatitis (AD), named also atopic eczema, is a chronic relapsing inflammatory skin disease with a considerable social and economic burden. The primum movens of AD is in most cases a genetic and/or immune‐supported defect of the skin barrier, facilitating penetration and sensitization to food or airborne allergens, as well as infections by Staphylococcus aureus, herpes simplex virus, or other microbes. New pathogenetic concepts have generated new approaches to prevention and therapy of AD. In particular, the daily use of emollients in newborns at high risk of AD has shown interesting results, with a reduction in the cumulative incidence of AD ranging from 32% to 50% of the treated infants. On the other hand, the AD preventive efficacy of food and/or inhalant allergen avoidance has been questioned, and supplementation strategies (vitamin D, probiotics, or other compounds) need to be further investigated.     

Prevalence and risk factors of childhood asthma, rhinitis and eczema in Hong Kong

Objective:   To assess the prevalence and risk factors of childhood asthma and allergies in Hong Kong and compare with that in Singapore and Great Britain.
Methodology:   Parents of 3618 randomly selected 6- to 7-year-old children responded to a questionnaire prepared by the International Study of Asthma and Allergies in Childhood (ISAAC) together with supplementary questions on risk factors.
Results:   The 12-month prevalences of wheezing, rhinitis symptoms and itchy rash were 9.2%, 35.1% and 4.2%, respectively. Wheezing in the past year was significantly associated with rhinitis symptoms in the past year, itchy rash in the past year, rhinitis interfering with daily activities moderately or severely, kept awake by itchy rash in the past year, parental wheezing (one or both parents), frequent upper respiratory tract infections (URTI), born in Hong Kong and male sex. For girls, the prevalence of wheezing in the past year was lowest when they were born in July/August and highest when born in January/February.
Conclusions:   The prevalence of allergic disorders in Hong Kong was comparable to that in Singapore and Great Britain. Several potential risk factors such as parental wheezing, frequent URTI, born in Hong Kong, male sex and month of birth in girls were identified.     

Obesity and the prevalence of allergic diseases in schoolchildren

Although the association between obesity and bronchial asthma (BA) has been gaining more attention, few studies have been conducted concerning the relationship between obesity and other allergic diseases. The objective of this study was to determine whether and how childhood obesity is associated with allergic diseases other than BA, such as atopic dermatitis (AD), allergic rhinitis (AR), allergic conjunctivitis (AC), and either AR or AC (AR/AC). A questionnaire was administered to the parents of 50,086 Japanese schoolchildren. Associations between childhood obesity and the various allergic diseases were evaluated by univariate and multivariate logistic models. Significant associations were found between higher body mass index (BMI) and AD (p = 0.03), and lower BMI and AC (p < 0.0001), and AR/AC (p < 0.0001). There was a significantly higher prevalence of BA in girls with obesity (p = 0.009) than in those without obesity. Significantly lower prevalence of AC (p = 0.01) and AR/AC (p = 0.002) among children with obesity, and AR (p = 0.04) and AR/AC (p = 0.0004) among boys with obesity were observed than those without obesity. Those who were obese and had AD were significantly more likely to have severe symptoms (p = 0.01). Overall, childhood obesity has positive associations with BA prevalence and AD severity, whereas it has negative associations with AR and AC prevalence, especially among boys. Changes in the immunologic balance accompanied by obesity might have different effects on each type of allergic disease. Exploring the mechanisms by which childhood obesity affects allergic status should lead to new management options for childhood allergy.     

Trends in the prevalence and severity of asthma, rhinitis and atopic eczema in 6- to 7- and 13- to 14-yr-old children from the north-east of England

The aims of the present study were to assess time trends in symptoms of asthma, rhinitis and atopic eczema among children in the north-east of England. Two cross- sectional surveys 6 yr apart, 6- to 7- and 13- to 14 yr of age, using the International Study of Asthma and Allergies in Childhood, core questionnaire were performed. There was a general increase in symptoms for all the three conditions in both the age groups. In the age group 6- to 7 yr, the increase was generally the same in boys and girls, while in the age group 13- to 14 yr, the increase was generally more marked among boys. In the younger age group, indices related to lifetime diagnosed ever had asthma and having hay fever increased in girls but not in boys, while indices related to lifetime diagnosis of ever having eczema increased in boys and girls. In the older age group, indices related to lifetime diagnosis of ever had asthma slightly increased in boys but did not change in girls, while lifetime diagnosis of ever having hay fever slightly decreased in girls but did not change in boys. The prevalence of lifetime diagnosis of ever having eczema increased in boys and girls. Changes observed in the present study could be related to the changes in lifestyle or environmental factors, awareness or management of symptoms.     

The natural history of allergic rhinitis in childhood

Keil T, Bockelbrink A, Reich A, Hoffmann U, Kamin W, Forster J, Schuster A, Willich SN, Wahn U, Lau S. The natural history of allergic rhinitis in childhood.
Pediatr Allergy Immunol 2010: 21: 962–969.
© 2010 John Wiley & Sons A/S The distinction between ‘seasonal’ and ‘perennial’ allergic rhinitis (AR) is not always adequate. The ‘Allergic Rhinitis and its Impact on Asthma’ (ARIA) work group suggested a new classification for AR based on severity and duration of symptoms. Our primary aim was to describe the natural history and burden of AR according to the new ARIA criteria in a population‐based birth cohort study of children up to 13 yr. We defined symptoms as ‘severe’ (impairment of daily activities) or ‘mild’ (no impairment) and ‘persistent’ (duration > 1 month) or ‘intermittent’ (≤1 month) using annual questionnaires. Serum immunoglobulin E to five common aero‐allergens was determined at six time points. We analyzed complete follow‐up data from 467 children (54% boys). The 12‐month prevalence of AR quadrupled from 6% (at age 3 yr) to 24% (at age 13 yr) in children with non‐allergic parents and more than tripled from 13% (3 yr) to 44% (13 yr) in children with at least one allergic parent. Half or more of the children with AR had ‘severe persistent’ symptoms. At age 13, these children were significantly more often sensitized than those with ‘mild persistent’ disease: 91% vs. 70% (p = 0.015). Sensitization to aero‐allergens (adjusted OR 18.9; 95%CI 9.3–38.4) and having 2 parents with allergy (3.1; 1.1–9.3) were significantly associated with AR. According to the ARIA criteria, the impact of AR seems to be substantial; the vast majority of affected children suffered persistently for periods of 2 months or more annually, and most of the children with persistent AR were impaired in their daily activities.     

The prevalence, characteristics of and early life risk factors for eczema in 10-year-old children

Eczema is a common infantile disease but its nature and extent during later childhood remains unclear. In a whole-population birth cohort study (n = 1456) we examined prevalence and characteristics of eczema amongst 10-year-old children. At this age 1373 (94%) children completed ISAAC questionnaires, 1043 (72%) skin prick testing and 953 (65%) serum inhalant IgE antibody screening. At 10 years of age prevalence of eczema ever was 41.0% and for current eczema was 13.7% (combined current itchy rash and eczema ever). Most current eczema (71.0%) began before 4 years of age, but was associated with low morbidity at 10 years. Amongst children with diagnosed eczema at 4 years of age, 56.3% had current eczema at 10 years. Atopy (positive skin test) and other allergic states were associated with current eczema (p < 0.001). Risk factor analysis for current eczema identified independent significance for atopy (p = 0.01), rhinitis (p = 0.04) and food allergy (p = 0.01) at 4 years, plus maternal asthma (p = 0.03). Diagnosed rhinitis at 4 years emerged as a significant predictor of persistent disease. Eczema is not simply a transient infantile condition but a common problem at 10 years of age, often reflecting persistent disease from early childhood. Inherited predisposition towards atopy is the predominant risk factor for this state.     

Ecological correlation among prevalence of asthma symptoms, rhinoconjunctivitis and atopic eczema with notifications of tuberculosis and measles in the Brazilian population

This study aims to assess the relationship among incidence of tuberculosis and measles, in the general population, within the year of birth and the prevalence of asthma, rhinoconjunctivitis and atopic eczema in teenagers from different Brazilian cities enrolled in the International Study of Asthma and Allergies in Childhood (ISAAC) phases I and III. Positive answers to the questions: ‘Have you had wheezing or whistling in the chest in the past 12 months?’, ‘In the past 12 months, has this nose problem been accompanied by itchy-watery eyes?’ and ‘Has this itchy rash at any time affected any of the following places: the folds of the elbows, behind the knees, in front of the ankles, under the buttocks, or around the neck, ears or eyes?’ identified the teenagers with asthma, rhinoconjunctivitis, and atopic eczema, respectively. The incidence of tuberculosis and measles, in the general population, observed in the year of birth of the enrolled teenagers (1981/82 and 1988/89) were obtained from governmental agencies: National Foundation of Health (FUNASA) and Brazilian Institute of Geography and Statistics (IBGE). They were compared with the prevalence of asthma, rhinoconjunctivitis and atopic eczema reported in both ISAAC phases I and III. Although we observed reduction of the incidence of tuberculosis and measles in the general population in all cities, the prevalence of asthma, rhinoconjunctivitis and atopic eczema remained stable in most of the centers. In Pernambuco and Paraná, there has been a significant increase in the prevalence of rhinoconjunctivitis. These data do not corroborate the findings of an inverse relationship between the prevalence of atopic diseases and the decreasing incidence of tuberculosis and measles.     

Wheeze in children: the impact of parental education on atopic and non‐atopic symptoms

de Meer G, Reijneveld SA, Brunekreef B. Wheeze in children: the impact of parental education on atopic and non‐atopic symptoms.
Pediatr Allergy Immunol 2010: 21: 823–830.
© 2009 John Wiley & Sons A/S There is conflicting evidence for the relationship between parental socioeconomic position and their children’s asthma. The aim of this study was to investigate relationships between parental education and respiratory symptoms in their children, distinguishing atopic and non‐atopic symptoms. A cross‐sectional survey among 3262 elementary school children (age 8–13) was performed; data on parental education were obtained for 3213 children. Parents completed a questionnaire on their child’s allergic and respiratory symptoms, and potential explanatory variables including family history, indoor environment, and the child’s medical history. Subsets of children were tested for atopy (n = 1983), lung function (n = 2325), and airway hyperresponsiveness (AHR) (n = 880). Logistic regression was used to assess relationships of health outcomes with parental education. A high parental education was associated with an increased risk of atopic sensitization to indoor allergens (OR 1.31, 95% CI 1.02; 1.69). Studied explanatory variables did not influence the relationship. In contrast, a high parental education protected children from wheeze (OR 0.77, 95% CI 0.61; 0.97). This only applied to non‐atopic wheeze (OR 0.65, 95% CI 0.43; 0.99) and not to atopic wheeze (OR 0.89, 95% CI 0.60; 1.31). The protection from non‐atopic wheeze in children of highly educated parents declined after adjustment for household smoking and breastfeeding (OR 0.96, 95% CI 0.58; 1.57). Similar results were observed for non‐atopic and atopic rhinitis. We conclude that children from highly educated parents are protected from non‐atopic respiratory symptoms, which is largely explained by a lower rate of household smoking and a higher rate of breastfeeding.     

Current cat ownership may be associated with the lower prevalence of atopic dermatitis, allergic rhinitis, and Japanese cedar pollinosis in schoolchildren in Himeji, Japan

The aim of the study was to clarify the relationship between current pet ownership, passive smoking, and allergic diseases among the Japanese children. From 1995 to 2001, we distributed the Japanese edition of the questionnaire of the American Thoracic Society and the Division of Lung Diseases (ATS-DLD) to survey allergic diseases among 35,552 6-yr-old children at primary school in the city of Himeji, Japan. We analyzed the data by multiple logistic regression and calculated adjusted odds ratios for environmental factors, including passive smoking and pet (dog and/or cat) ownership. There were no significant relationships between the prevalence of asthma and current pet ownership and passive smoking. However, current cat ownership was related to a significantly lower prevalence of atopic dermatitis [adjusted odds ratio (aOR) 0.79, 95% confidence interval (CI) 0.67-0.93], allergic rhinitis (aOR: 0.71, 95% CI 0.57-0.89) and Japanese cedar pollinosis (aOR 0.57, 95% CI 0.44-0.75). Strikingly, passive smoking was also related to a significantly lower prevalence of allergic rhinitis (aOR 0.83, 95% CI 0.77-0.89) and Japanese cedar pollinosis (aOR 0.81, 95% CI 0.74-0.88). Current cat ownership was associated with a lower prevalence of atopic dermatitis, allergic rhinitis, and Japanese cedar pollinosis. In addition, passive smoking was also associated with a lower prevalence of allergic rhinitis and Japanese cedar pollinosis.