Histamine is a low-molecular-weight monoamine that binds to four different G-protein-coupled receptors, and has recently been demonstrated to regulate several essential events in the immune response. The histamine receptor type 2 (HR2) is coupled to adenylate cyclase and studies in different species and several human cells have demonstrated that inhibition of characteristic features of the cells by primarily cAMP formation dominates in HR2-dependent effects of histamine. (more…)

The immunologic mechanisms of sublingual immunotherapy are less established. In Cochrane analysis, the authors concluded that there was an increase in IgG4 but no stable effect on IgE levels in adults. In addition, the induction of allergen-specific IgA has been reported. There are conflicting data concerning lympho-proliferative responses. So far the evidence on changes in Th1/Th2/Treg activity induced by sublingual immunotherapy need to be confirmed. The effects on T-cell reactivity and cytokine secretion show strong variation in a number of studies. (more…)

Airway hyper-responsiveness in asthma may involve smooth muscle growth, a manifestation of airway remodelling. The involvement of inflammatory cells in the induction of airway smooth muscle growth was studied in vivo and ex vivo in a brown Norway rat model of asthma. Transfer of CD4 + T lymphocytes from ovalbuminsensitized animals induced an increase in airway smooth muscle mass in naive animals upon repeated ovalbumin challenge. Ex vivo, coculture of antigen-stimulated CD4 + T cells and airway smooth muscle cells led to myocyte proliferation and prolonged T-cell survival. (more…)

Systemic allergic reactions are a relatively common clinical emergency. In their mildest form, they may just manifest as systemic cutaneous reactions with pruritis, allergy urticaria and angioedema. In more severe cases there are cardiorespiratory symptoms such as stridor, wheeze, difficulty in breathing or hypotension. Anaphylaxis has been defined as a ‘severe, life-threatening generalized or systemic hypersensitivity reaction’. The prevalence of systemic allergic reactions is unclear because of the lack of a clear, consistent definition and large prospective population studies. (more…)

Atopic dermatitis is a chronic inflammatory condition of the skin which usually starts in infancy. It is sometimes called ‘atopic eczema’ or even simply ‘eczema’. Recently, the term ‘atopic eczema dermatitis syndrome’ or eczema symptoms or infantile eczema has also been proposed to indicate the varied nature of this disease. The diagnosis is based on clinical features of a chronic itchy dermatitis with typical morphology and distribution and a relapsing and remitting course. (more…)

Antihistamines have been shown to be effective in seasonal allergic rhinitis and chronic idiopathic urticaria. They improve quality of life scores, acute inflammatory response markers in atopic dermatitis asthma and symptom scores. Newer histamine H1-receptor antagonists may also have an antiplatelet-activating factor effect and are equally effective in seasonal allergic rhinitis. The antileukotrienes were developed in the 1980s. The first compounds of this novel class of anti-asthma drugs were registered in the second half of the 1990s. The mechanism of action of the cysteinyl leukotriene receptor antagonists (LTRAs) is based on counteracting the effects of cysteinyl leukotrienes at their receptor site (CysLT1 receptor) within the airways. (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.

It is very common in asthmatic children where overprotective parents prevent a normal level of exercise to their kids. However, a controlled sport appropriate to the course of their disease is very healthy.

Asthma is an inflammatory disease of the airways characterized by variable bronchial obstruction and reversible, either spontaneously or with treatment, (more…)

Atopic Dermatitis is a chronic relapsing skin disease. Several investigations concerning the long-term prognosis of Atopic Dermatitis in children and teenagers have been performed but there are few data for adults. The aim of this study was to investigate the prognosis and prognostic factors in adult patients with Atopic Dermatitis using a long-term follow-up (25–38 years). A follow-up questionnaire was sent to 922 Atopic Dermatitis patients examined in an out-patient clinic between 1960 and 1973 among 1366 registered patients with Atopic Dermatitis. The patients were aged 20 years or older when they visited the clinic and 45 years or older when they answered the follow-up questionnaire. (more…)

If an exclusively breast-fed baby is exhibiting the type of allergic to milk symptoms previously discussed, the mother will inevitably question whether foods in her diet are responsible. Of course, the first thing she must do is consult her baby’s doctor to rule out any other cause for the symptoms. (more…)