Exposure and allergic sensitization to cockroach was associated with a significantly greater risk of asthma hospitalization and greater healthcare utilization among 476 children aged 4 to 9 years who participated in the National Cooperative Inner-City Asthma Study. Allergic sensitization to the mold Alternaria has been identified as a significant allergen in terms of increasing airway hyperresponsiveness and was associated with a nearly 200-fold increased risk of respiratory arrest due to asthma, emphasizing the importance of determining underlying allergic sensitivities in patients with asthma and providing patients with accurate and practical advice on allergen avoidance techniques. (more…)

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A general pattern of factors influencing development of asthma seems to be emerging, including family allergy history/ asthma genetics, smoking, diet, obesity, and inactivity, all of which seem to influence the development of asthma and disease outcomes (Table bellow).

Many clinical or area studies have reported substantially higher rates of asthma prevalence, hospitalization, and mortality among racial and ethnic minorities. However, asthma is also most common among low socioeconomic groups, regardless of race. While black children have higher rates of asthma than white children, most studies have found that black race is not a significant correlate of asthma after controlling for location of residence and socioeconomic status (SES). The basis for the effects of poverty and urban residence on asthma prevalence is not known. One potential asthma factor is allergen exposure and allergen sensitization are common in urban environments. Black children in inner city Atlanta are exposed to high levels of dust mites and cockroach allergen, and a high proportion of the children with asthma were sensitized to these allergens. Litonjua and colleagues also concluded that a large proportion of racial/ethnic differences in asthma prevalence can be explained by factors related to income, area of residence, and level of education.

Asthma Factors that Influence Disease Development and Severity

Income is a determinant of access to health care, and frequently, the quantity and quality of health care available. Persons who have low income, regardless of race or ethnicity, are more likely to be uninsured, to encounter delays or be denied care, to rely on hospital clinics in emergency departments for health services, and to receive substandard care. The usual socioeconomic indicators, education and personal or household income, serve only as surrogates for more complicated correlates of individuals within populations and multiple asthma factors that can impact both on prevalence of asthma and adverse outcomes from the disease.

Studies from Germany comparing the populations of East and West Germany have shown the prevalence of hay fever and asthma as significantly higher in West German children, suggesting that asthma environmental factors explain the difference in prevalence in these ethnically similar populations. Early exposure to infections (as with being in a day-care environment early in life) or exposure to endotoxin (as with growing up on a farm with close exposure to the farm animals) are associated with a decreased prevalence of asthma. In contrast, growing up in an urban environment or generally with an increased standard of living are associated with an increased prevalence of asthma. Such correlates are also present for atopic disorders other than asthma. In fact, Strachan, who noted that prevalence of hay fever was inversely related to family size, was the first to recognize the importance of early exposures on atopic disease. In the USA, asthma is more prevalent in African-Americans and Puerto Ricans. These findings are not explained by the observations on the role of social class in European studies. Given the ethnic differences between African-Americans and whites, these studies may represent gene-by-environment interaction producing varied phenotypic outcomes.

The intracellular forkhead winged transcription factor Foxp3 (forkhead box P3) appears to be specifically expressed by naturally occurring Treg cells, particularly in mice, although in humans there is evidence of upregulation of Foxp3 in all T cells on activation. Foxp3 is required for the development and function of naturally occurring regulatory t cells (treg) and expression is sufficient to convert non-regulatory CD4+CD25T cells into cells with regulatory activity. Conversion of peripheral CD4+CD25 naive T cells to Foxp3+CD4+CD25 foxp3+ Treg cells can be induced by TGF-ß. In a murine asthma model, these TGF-ß-induced Treg prevented house-dust mite-induced allergic pathogenesis or infection pathogenesis in lungs. A single independent report has suggested that IL-4 and IL-13 also induce Foxp3+CD25+ Treg from CD4+CD25precursors. (more…)

This study examined the genetic basis of sensitization to house dust mite allergy allergens. A genome scan was conducted using 603 microsatellite markers in 82 nuclear families (366 individuals) of German, British and Portuguese origin with at least two affected siblings. Sensitization to Dermatophagoides pteronyssinus was assessed by determining specific IgE antibody levels detected by immunochemiluminometric assay and immunosorbent assay and categorized as positive or negative relative to a predetermined cut-off point. (more…)

This population-based cross-sectional study, funded by a UK government agency, aimed to establish the rate of sensitization to food allergens, reported food hypersensitivity, food avoidance and objectively assessed food hypersensitivity in 11- and 15-year-olds living on the Isle of Wight, UK. The researchers approached the teenagers via their schools, and a questionnaire completed by the parents and children formed the basis of capturing data to determine the prevalence of current reported food hypersensitivity and rates of food avoidance. This information was available on 775 individuals aged 11 years and 757 aged 15 years. (more…)

Natural history studies with the following design features provide a firm epidemiologic foundation for risk factor assessments and etiologic hypotheses:
(1) long-term cohort studies of a prospective design minimize biases resulting from poor parental recall;
(2) multiple evaluations over time provide important checkpoints during the dynamic period of childhood growth and development; and
(3) the inclusion of objective disease measurements strengthens these studies by validating subjective disease assessments (i.e. questionnaire data). (more…)

Atopic Dermatitis is considered to be one of the first manifestations in the atopic march. The aim of this study was to investigate prospectively the natural course of Atopic Dermatitis to determine factors influencing its prognosis and to analyse the relationship of Atopic Dermatitis with childhood asthma. The Multicenter Allergy Study, a German birth cohort, followed 1314 children from birth to age 7 years. Physical examinations, parental interviews on atopic symptoms and diagnoses, and determination of specific immunoglobulin (Ig)E levels were performed regularly. (more…)

The increasing prevalence of allergic disease in the Western world has led to the concept of the ‘allergic march’ to describe the evolving spectrum of disease that often begins in childhood. The use of allergen immunotherapy in children has the potential of altering the natural course of allergic disease. However, concerns regarding the safety of using this treatment in children are an obstacle to attenuating the allergic march. The study of Di Rienzo and colleagues reviews the safety of Sublingual Immunotherapy in children between the ages of 3 and 5 years. (more…)

In the Tucson CRS study, about 50% of young children experienced a period of recurrent wheezing and/or coughing in the first 6 years of life. These early-childhood wheezers were further subdivided into (1) ’transient early wheezers,’ with wheezing only <3 years; (2) ‘persistent wheezers,’ with manifestations through the first 6 years; and (3) ‘late-onset wheezers,’ with manifestations only after 3 years. Transient wheezers comprised the largest proportion of the group at 20%; persistent and late-onset wheezers made up slightly smaller proportions (14% and 15%, respectively). (more…)

Seasonal allergic rhinitis is stimulated by an allergic reaction of human body to pollen and spores. This is much depending on the season and region as they are carried by the wind. Your doctor may recommend you to undergo allergies medication that depends on your type of allergy rhinitis. (more…)