Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated immune response appears to be an important pathogenetic factor. Cardinal events during allergic inflammation can be classified as activation, organ-selective homing, survival and reactivation, and effector functions of immune system cells. T cells are activated by aeroallergens, food antigens, autoantigens, and bacterial exotoxins superantigens in allergic inflammation. They are under the influence of the skin, lung, or nose-related chemokine network and show organ-selective homing. (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.

Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunctivitis, asthma, and venom allergy hypersensitivity. It is the only treatment that leads to lifelong tolerance against previously disease-causing allergens due to restoration of the normal immunity. (more…)

The immune system consists of proteins, cells and organs that are concerned with defense of the individual, primarily against the threat of disease caused by infectious organisms. An infectious organism that causes disease is called a pathogen and the individual (person or animal) that is infected by a pathogen is called the host. Not all infectious organisms cause disease and some are actually beneficial, for example bacteria living in the gut help to digest certain foods. Infectious organisms that help the host are called commensalism organisms. (more…)

Treating allergic rhinitis may have a downstream effect on concomitant asthma and this may be due to attenuation of the underlying inflammatory process.

Fexofenadine and montelukast exhibited additive effects to moderately high doses of inhaled corticosteroids when used as add-on therapy in the treatment of patients with persistent atopic asthma. (more…)

Allergic rhinitis is a very common problem associated with poor quality of life, reductions in social and work activities and poor interpersonal relationships. The main goal of the management of allergic rhinitis is to improve the quality of life. Immunotherapy is a specific therapy for allergic rhinitis and several reports have documented the safety and efficacy of this treatment . Safety has been a key issue in immunotherapy and various modalities are being investigated to make allergy immunotherapy more tolerable and safe to administer. (more…)

Asthma and allergic diseases are common in both children and adults. Their development depends on an interaction between asthma genetic and asthma environmental risk factors. Genetic manipulation in multi factorial diseases such as asthma is not feasible in the foreseeable future. However, theoretically, environmental exposures can be controlled in an attempt to stem the rising prevalence of these diseases (primary prevention). Environmental exposures may also influence the frequency of symptoms and the requirement for medication in those with established disease. (more…)

To prevent the development of allergy, allergen avoidance has to be instituted before sensitization has occurred. The specific type of aero allergens may vary depending on the climatic and economic situation. For example, House Dust Mite is the most important allergen in humid climates and pet allergens assume importance in cold countries, while cockroach allergen is the major sensitizing agent in crowded, inner city areas. Several large prospective studies have instituted House Dust Mites avoidance measures during pregnancy, at birth and later in childhood, and assessed children for asthma and allergic manifestations. (more…)

There is much controversy as to the role of allergen exposure for the development of atopic sensitization towards this allergen. While in some studies, a clear, almost linear dose-response relation between allergen exposure and sensitization has been found, others described a bell-shaped association with higher levels of exposures relating to lower rates of atopic sensitization. Part of the discrepancy may relate to the type of allergen, since mostly cat but not house dust mite allergy allergen exposure has been shown, in some studies, to exert protective effects at higher levels of exposure. (more…)

By definition, allergy is a condition where a person has hypersensitivity to an environmental, drug, or food antigen (allergen) caused by an altered or unusual immune system reaction to the antigen.

Allergenic foods can impact the lungs when an allergic reaction individual inhales food particles that may have been released when the food was cooked or that were dispersed in aerosol form. Allergy to the allergens in cooked food has been reported by highly allergic patients who were exposed to their allergenic foods (say, fish, shellfish, or eggs) in an enclosed area (for example, a restaurant dining room) or during meal preparation. Most cases of asthma triggered by aerosolized food allergens involve adults engaged in specific occupations that regularly expose them to the allergens. In contrast, most cases of asthma in children are triggered when the allergen is eaten, not inhaled.

Many experts believe that if a baby can be protected from becoming sensitized to the most highly allergenic foods when their healthy immune system and the digestive tract are in the most vulnerable stage for allergy to develop, the incidence of lifelong food allergy and potentially life-threatening anaphylactic reactions to foods will be reduced and hopefully entirely prevented. When a baby has been identified to be at risk for developing allergy, measures to reduce allergic sensitization might be implemented at birth and the problems associated with future food allergy may be significantly reduced. However, as we shall see in later discussions, experts disagree on the best way to avoid this early allergic sensitization.

The reaction of asthmatics to these chemical compounds is not an allergy, but is more correctly described as allergy intolerance because the initial response is not a triggering of the immune system. The process involves an increase in the level of the inflammatory mediators that are responsible for the bronchospasm of asthma. These mediators include histamine and leukotrienes. They are released during the reaction to an allergen, and cause the muscular contractions that result in the difficulty in breathing and wheezing that are typical of asthma. By inhibiting (or turning off) other types of mediators, the chemicals in the food additives cause an increase in the level of antihistamine and leukotrienes. This results in increased bronchospasm, and a definite worsening of the asthma symptoms.

Oral allergy syndrome is an allergic reaction to food that is confined to the oral cavity (i.e., to the lips, and around the lips, roof of the mouth, tongue, hard and soft palate, and uvula) and adjacent structures. It differs from other food allergy in that its symptoms do not appear in any other location in the body, and always accompany respiratory allergy to inhaled allergens of plants, particularly plant pollens. Of course, symptoms in the mouth, throat, and upper respiratory tract can be part of a generalized reaction to foods, but in this case they are more accurately described as oral allergy symptoms. The term oral allergy syndrome applies specifically to pollen allergy (pollinosis) accompanied by reactions to certain raw foods when they are in direct contact with oral tissues. Individuals with Oral allergy syndrome typically have hay fever symptoms caused by allergies to trees, grasses, and weeds. They experience irritation in the mouth (lips, tongue, roof of the mouth) and sometimes the throat after eating specific types of raw fruits, vegetables, and sometimes nuts.