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.     

Allergy: a systemic disease? The HUNT and Young–HUNT study,Norway.

A systemic nature of allergic diseases has been hypothesized. As part of this discussion, we studied if adolescent allergic wheeze and increasing combinations of allergic organ involvements (lung, nose and skin) would also increase the reporting of other health problems (headache, muscle pain and abdominal pain). In addition, we studied if parental asthma was associated with adolescent clustering of allergic expressions and if parental asthma with additional health problems (headache or muscle pain) was associated with adolescent reporting allergy in combination with headache, muscle pain and abdominal pain. Adolescents 13–19 yr (n = 8817, 89%) participated in the Young–HUNT study, Norway, 1995–97. Parental data on asthma were eligible in n = 5620. Health and lifestyle were measured by questionnaires and interviews. Associations with additional health problems were significantly strengthened with combinations of wheeze and other allergic expressions. Odds Ratio for associations ‘wheeze only’, ‘wheeze and rhinitis’ and ‘wheeze, rhinitis and eczema’ were for headache 2.1, 3.4 and 3.7; for muscle pain 2.8, 3.2 and 4.9; for abdominal pain 3.6, 4.0 and 4.9. All p for trend were <0.010. Similar results were obtained when studying allergic wheeze; p for trend <0.001. Parental asthma was associated with clustering of adolescent allergic expressions, and parental asthma with headache or muscle pain was significantly associated with reported allergy combined with similar health problems in their offspring. The results indicate that allergy may be expressed beyond organs commonly viewed as part of an allergic disease, and hence may support a hypothesis of a systemic nature of allergic diseases.     

Different sensitization profile for asthma, rhinitis, and eczema among 7-8-year-old children: Report from the Obstructive Lung Disease in Northern Sweden studies

Sensitization to different airborne allergens in relation to asthma, rhinitis, and eczema has been studied. A cross-sectional study was performed among 7–8-year-old children living in northern Sweden. The ISAAC-questionnaire with additional questions were sent to the parents, and 3431 (97%) participated. Two-thirds of the children were invited to undergo a skin test with 10 common airborne allergens, and 2148 (88%) participated. The prevalence rates of all three diseases were significantly higher among the children who were sensitized to any of the tested allergens. Among asthmatics, 40% were sensitized to cat, 34% to dog, 28% to horse, 23% to birch and 16% to timothy. The corresponding figures for rhinitis were: cat 49%, dog 33%, horse 37%, birch 46%, timothy 32%; and for eczema: cat 29%, dog 21%, horse 15%, birch 20%, and timothy 11%. Only a few children were sensitized to mites or moulds. The main risk factors for all three diseases were type-1 allergy and a family history of the disease. Independently from other risk factors, sensitization to dog (OR 2.4) and horse (OR 2.2) were significant risk factors for asthma. Sensitization to birch (OR 6.0), horse (OR 4.1), and timothy (OR 2.8) were significant risk factors for rhinitis, while birch (OR 2.4), dog (OR 2.0) and cat (OR 1.6) were significant risk factors for eczema. Despite a large over-lapping of the diseases the pattern of sensitization was different for asthma, rhinitis and eczema. Sensitization to cat was most common among all children, but sensitization to dog and horse was associated with the highest risk for asthma, and sensitization to birch showed the highest risk for rhinitis and eczema. The different risk factor pattern for the often coexisting diseases; asthma, rhinitis, and eczema, may indicate differences in the etiology.     

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.     

Changes in the prevalence of asthma and allergic diseases among Brazilian schoolchildren (13-14 years old): comparison between ISAAC Phases One and Three

The present study is aimed to describe the changes in the prevalence of symptoms of asthma, rhinitis and eczema among Brazilian adolescents (AD, 13-14 years old) between Phases 1 and 3 of the International Study of Asthma and Allergies in Childhood (ISAAC). The prevalence of self-reported symptoms of asthma, rhinitis and eczema in AD from five Brazilian cities (Curitiba, Porto Alegre, Recife, Salvador and S?o Paulo), obtained during ISAAC Phase 1 (n = 15 419) and Phase 3 (n = 15 684), was compared to determine the trend of prevalence in a 7-year interval. There was a trend to reduction in the current prevalence of wheezing and increasing of nocturnal cough when averaging figures from the five cities. The prevalence of wheezing in the last 12 months was 27.7 vs. 19.9% (p < 0.01); asthma ever 14.9 vs. 14.7% (p > 0.05); severe episode of wheezing 5.2 vs. 5.2%; nocturnal cough 32.6 vs. 34.9% (p < 0.01); exercise wheezing 23.6 vs. 23.0% (p > 0.05) and awake with wheezing 11.8 vs. 11.2% (p > 0.05). Similar things were observed with the prevalence of current symptoms of rhinitis and eczema. In Brazil, there was a small but significant mean decrease in the prevalence of two asthma-related symptoms, wheezing and nocturnal cough, though this trend was not consistent in the surveyed cities. The prevalence of asthma symptoms in Brazil, despite its mean trend to a decrease, is still one of the highest in Latin America.     

Allergic status of schoolchildren with food allergy to eggs, milk or wheat in infancy

Although children allergic to eggs, milk or wheat in infancy tend to become tolerant by school age, the allergic status of these children at school age has not been well evaluated. To investigate the allergic status of schoolchildren who avoided eggs, milk or wheat because of an immediate-type allergic reaction at <1-yr-old (food avoiders in infancy), we conducted a large-scale questionnaire-based survey of schoolchildren. A questionnaire on allergic diseases was distributed to the parents of 14,669 schoolchildren aged 7 to 15 yr in 30 schools in Kyoto, Japan. Of these, 13,215 responded (response rate, 90.1%). The rate of 7-yr-old children who were food avoiders in infancy was 5.4%. This rate decreased as the current age of the children increased, down to 3% in 15-yr-old children, indicating that food allergy in infancy tended to become more prevalent over the past 8 yr. Although more than 80% became tolerant to these foods by school age, the prevalence of bronchial asthma, atopic dermatitis, allergic rhinitis and allergic conjunctivitis were significantly higher in this group. Moreover, avoidance of other foods (buckwheat, shellfish, fruits and others) at school age was seen at much higher frequencies than in non-food avoiders in infancy (adjusted odds ratio, 7.7; confidence interval, 5.9–10.2). This risk did not differ significantly between those who did and did not develop tolerance to eggs, milk and wheat by 3 yr old. In conclusion, food avoiders in infancy appear to have a higher risk of not only other allergic diseases ('atopic march') but also allergy to other foods ('food allergen march') at school age, indicating the need for continuous attention to food allergy.     

Prevalence of asthma and allergic diseases in primary school children in Ankara, Turkey: Two cross‐sectional studies, five years apart

The prevalence of allergic diseases is reported to have increased worldwide. Two questionnaire surveys, five years apart, were conducted to evaluate the trend of prevalence rates and possible risk factors among primary school children in Ankara, Turkey. A previous survey in 1992 revealed the lifetime prevalences of asthma, wheezing, allergic rhinitis and atopic dermatitis were 17.4%, 23.3%, 28% and 6.1%, and the prevalences for the preceding 12 months were 8.3%, 11.9%, 15.4% and 4%, respectively. The survey was repeated with the same questionnaire in the same age group (6–13 years) of the same school in May 1997. The parents of 358 boys and 380 girls completed the questionnaire. The lifetime and last 12 months' prevalences of asthma, wheezing, rhinitis and atopic dermatitis were 16.8%, 22.5%, 18.7%, 6.5%, and 9.8%, 13.3%, 14.1%, 4.3%, respectively. There was a significant change only for the lifetime prevalence of rhinitis (p < 0.001). The rate of indoor smoking had declined from 73.9% to 64%, and pet ownership had risen from 7.9% to 22.9% (p < 0.001 for both). Atopic family history was the most prominent risk factor for all types of allergic disorders. Male gender was a significant risk factor for current asthma and wheezing [odds ratio (OR) = 1.80 and 1.59; 95% confidence intervals (CI) = 1.09–2.98 and 1.01–2.48, respectively], and passive smoking affected the occurrence of allergic rhinitis (OR = 1.84; CI = 1.13–3.00). The prevalence rates of allergic diseases among primary school children in Ankara stabilized during a 5‐year period for all diseases other than allergic rhinitis. However, there are changing behavior patterns, i.e. indoor smoking and keeping pet animals, which that may have affected these rates.