Prevalence of asthma among young men in a military recruitment office of South Italy

Allergic diseases in infancy: I - Epidemiology and current interpretation

Objective

Among non-communicable diseases, the prevalence of allergic diseases has increased significantly in the new millennium. The increase of allergic diseases is linked to the changing environment of infants.

Methods

This narrative review summarizes the discussions and conclusions from the 8^th Human Milk Workshop. Information from the fields of pediatrics, epidemiology, biology, microbiology, and immunology are summarized to establish a framework describing potential avenues for the prevention of allergic diseases in the future.

Results

Several environmental circumstances are linked to the development of allergic diseases. While cesarean section is increasing the risk of allergies, early childhood exposure to a farm environment has a protective effect. From their analysis, nutritive and non-nutritive factors influencing the allergy risk in later life have been identified. The effect of breastfeeding on food allergy development is non-univocal. Human milk components including immunoglobulins, cytokines, and prebiotics have been indicated as important for allergy prevention.

Conclusion

Many factors linked to the western lifestyle have been associated with the development of allergic diseases. This suggests several theories that may serve as a basis for new protective interventions. While it is indubitable that mother's milk protects from infectious diseases, its role in the prevention of allergic diseases is to be elucidated.

GENETIC AND ENVIRONMENTAL FACTORS AS STRONG DETERMINANTS OF ATOPIC ALLERGIC DISEASE CLINICAL MANIFESTATIONS IN SURABAYA'S SCHOOL CHILDREN

This case-control study was conducted to assess the relative role of genetic and environmental factors in determining the clinical manifestations of atopy allergy disease in school children, which is part of a large study of the prevalence of allergic diseases in school children in Surabaya. Using a simple multi-stage random sampling, 348 children from 5 elementary schools, 4 junior high schools, and 4 senior high schools in Surabaya were involved in the study. The subjects of the study along with her parents were guided to fill out the modified ISAAC questionnaire and underwent physical examination and skin prick test using 27 common allergen types found in the environment. For the analysis, 110 school children were randomly selected from the parent sample and included in the case group of 55 people (positive skin prick test against > 1 type of allergen), and the control group of 55 people (negative skin prick test). All genetic and environmental factors data were collected and analyzed. Most of the subjects had clinical manifestations of allergic rhinitis (66.36%), asthma (21.82%), food allergies (10.9%), and atopic dermatitis (6.36%). Complete models for multiple logistic regression analysis can only be performed for overall atopic disease and allergic rhinitis disease. The first birth order and exposure to home dust mites were the most significant clinical manifestations of atopy disease (OR 4.548, 95% CI: 1.813-11.410, p=0.01). Atopy status of the father was the only significant determinant factor for the manifestation of allergic rhinitis in the study subjects (OR 3.929; 95% CI: 1.143-13.052, p=0.03). Both genetic and environmental factors interacted and determined clinical manifestations of atopy allergy disease in school pupils. The father's genetic factors were more dominant than maternal genetic factors in determining the clinical manifestations of allergic rhinitis in offspring.

Allergic rhinoconjunctivitis continued to increase in Swedish children up to 2007, but asthma and eczema levelled off from 1991

AIM

This study investigated whether allergies among schoolchildren increased in Sweden between 1979 and 2007 and whether the geographical differences observed in previous studies remained.

METHODS

We collected questionnaire data on asthma, allergic rhinoconjunctivitis (ARC) and eczema in children aged seven to eight years from Mölndal, Gothenburg, in south-western Sweden and Kiruna in northern Sweden in 1979 (n = 4682), 1991 (n = 2481) and 2007 (n = 1029). The same regions and questions were used in all three studies, and extra questions on food allergy or intolerance were added in 2007.

RESULTS

In 1979, 1991 and 2007, the total prevalence of asthma was 2.5%, 5.7% and 7.1%, ARC was 5.5%, 8.1% and 11.1% and eczema was 7.1%, 18.3% and 19.7%, respectively. Asthma prevalence remained higher in Kiruna, but no significant regional differences were seen for ARC and eczema. Almost 20% reported a history of food allergy or intolerance, with a higher prevalence in Kiruna. The allergy risk was reduced if both parents were born outside Sweden.

CONCLUSION

The prevalence of ARC continued to increase between 1991 and 2007, but increases in asthma and eczema started to level off in 1991. Some geographical differences remained, but total allergy rates were similar in Kiruna and Mölndal in 2007.

Dampness in buildings as a risk factor for health effects, EUROEXPO: a multidisciplinary review of the literature (1998-2000) on dampness and mite exposure in buildings and health effects

The scientific literature on health effects from dampness in buildings, including mite exposure over the period 1998-2000 has been reviewed by an European group (EUROEXPO) of eight scientists in experience from medicine, epidemiology, toxicology and engineering. Forty studies deemed relevant have been the foundation for the conclusions. Dampness in buildings is a risk factor for health effects among atopics and non-atopics both in domestic and in public environments. However, the literature is not conclusive in respect of causative agents, e.g. mites, microbiological agents and organic chemicals from degraded building materials. There is a strong need for more multidisciplinary studies including expertise from all relevant areas. A general conclusion from the work was that there is a strong need for multidisciplinary reviews in scientific journals of articles dealing with associations between indoor environmental factors and health effects.

PRACTICAL IMPLICATIONS

There is good evidence for a true association between dampness in buildings and health. As the causative factors behind this association are not known, the main focus in practical investigations should be on finding out and remediate the reasons for the humidity problem.

Farm residence and exposures and the risk of allergic diseases in New Zealand children

BACKGROUND

Studies in Europe have reported a reduced prevalence of allergy in farmers' children. We aimed to determine if there is a similar reduction in allergy among New Zealand farm children.

METHODS

Two hundred and ninety-three children participated (60%) aged 7-10 years, from selected schools in small towns and the surrounding rural area. Skin prick tests (SPT) to eight common allergens were performed. Parents completed questionnaires about allergic and infectious diseases, place of residence, exposure to animals, and diet, and they provided dust from the living-room floor. Endotoxin was measured using an Limulus amoebocyte lysate (LAL) assay and Der p 1 using enzyme-linked immunoassay (ELISA).

RESULTS

Current farm abode was found to increase the risk of having symptoms associated with allergy, but not SPT positivity. Independent inverse associations were found for early-life exposures: at least weekly consumption of yoghurt with hayfever (odds ratio (OR) = 0.3, 95% confidence intervals (CI) 0.1-0.7) and allergic rhinitis (OR = 0.3, 95% CI 0.2-0.7); any unpasteurized milk consumption with atopic eczema/dermatitis syndrome (AEDS) (OR = 0.2, 95% CI 0.1-0.8); cats inside or outside with hayfever (OR = 0.4, 95% CI 0.1-1.0) and AEDS (OR = 0.4, 95% CI 0.2-0.8); dogs inside or outside with asthma (OR = 0.4, 95% CI 0.2-0.8); and pigs with SPT positivity (OR = 0.2, 95% CI 0.1-0.9).

CONCLUSIONS

Despite finding a protective effect of early-life animal exposures, we found a greater prevalence of allergic disease on farms.

Does a higher number of siblings protect against the development of allergy and asthma? A review

STUDY OBJECTIVE

To review the "protective" effects of having a higher number of siblings for the risk of atopic eczema, asthma wheezing, hay fever, and allergic sensitisation.

METHOD

Review of the literature (Medline since 1965 and references).

MAIN RESULTS

53 different studies were identified. For eczema, 9 of 11 studies reported an inverse relation with number of siblings; for asthma and wheezing, 21 of 31 reported the inverse association; for hay fever, all 17 studies showed the effect; for allergic sensitisation or immunoglobulin E reactivity 14 of 16 studies supported the "protective" effect of a higher number of siblings. The studies emphasise a "theory" that is based exclusively on epidemiological associations.

CONCLUSIONS

Research has not yet answered the question of which causal factors explain the sibling effect. Causal factors must meet two criteria; they must vary with sibship size and they must protect against atopic manifestations. The prevailing "hygiene hypothesis" failed to explain the findings adequately. Alternative explanations include in utero programming or endocrine explanatory models. The epidemiology research into siblings and atopic disorders has entered an intellectually challenging phase. Possessing sufficient knowledge about the causal factors might prevent at least 30% of all cases of asthma, eczema, and hay fever.

Farming, rural lifestyle and atopy in adults from southern Germany--results from the MONICA/KORA study Augsburg

BACKGROUND AND OBJECTIVE

The increasing urbanization and the decrease in the numbers of farms in southern Germany might be associated with an increasing prevalence of allergic diseases. We compared the prevalence of allergic diseases in farmers, and rural, suburban and urban residents in the small geographical area of Augsburg in southern Germany.

METHODS

In a cross-sectional survey adults, aged 25-75 years selected from the community population register were investigated. Rural, suburban and urban residents were defined by community size and farmers by occupation. Allergic respiratory disorders were assessed by self-administered questionnaires and specific IgE antibodies to five common aeroallergens.

RESULTS

In comparison to rural residents the urban population had an increased risk of allergic rhinitis (OR = 1.5; 95% CI: 1.2-1.9), atopic sensitization (OR = 1.2; 95% CI: 1.0-1.4) and sensitization against pollen (OR = 1.5; 95% CI: 1.2-1.9). There was no difference in the risk of asthma (OR = 1.0; 95% CI: 0.6-1.6) and a decreased risk in the sensitization against house dust mite (OR = 0.8; 95% CI: 0.7-1.0). The suburban residents did not differ from urban residents. Farmers had lower risks in allergic rhinitis, atopic sensitization, sensitization against pollen and mites (OR = 0.63; 0.86; 0.51 and 0.80, respectively) than rural non-farming residents, however, these differences were statistically not significant. Reported allergic rhinitis with sensitization to pollen was 2.5 times (95% CI: 1.8-3.6) more prevalent in urban than in rural residents.

CONCLUSION

A farming environment and rural lifestyle might be associated with unknown protective factors impacting the prevalence of allergies.