The diagnosis and management of anaphylaxis practice parameter: 2010 update.

These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "The Diagnosis and Management of Anaphylaxis Practice Parameter: 2010 Update." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, or the Joint Council of Allergy, Asthma and Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Food allergy: opportunities and challenges in the clinical practice of allergy and immunology.

Food allergy offers numerous opportunities and challenges for the allergy and clinical immunology specialist. Physicians with board certification in allergy and clinical immunology should be the main source of reliable clinical information to educate patients with food-related disorders. There has been a wealth of reliable information published related to food allergy that can be utilized by health care providers in clinical practice. This includes information about the cross-reactivity of food allergens, the evaluation of potential new therapies, and the practical application of new diagnostic methods and management strategies. This article addresses some of the new developments in food allergy, with an emphasis on cross-reactvity of food allergens, recombinant food allergens, and potential future therapies for food allergy.

Diagnosis and therapy of food allergy.

According to the recently revised nomenclature for allergy the term "Food Hypersensitivity" is proposed to define a reaction on food exposure causing objectively reproducible symptoms or signs at a dose tolerated by normal subjects. Those reactions to food in which immunologic mechanisms are demonstrated comprise the term "Food Allergy". Immunologic reactions to food in which an immunoglobulin E (IgE)-mediated mechanism is established are defined as IgE-mediated food allergy. This review focuses on IgE-mediated allergic reactions to foods.

Allergic reactions to foods by inhalation.

Although allergic reactions to foods occur most commonly after ingestion, inhalation of foods can also be an underlying cause of these reactions. For example, published reports have highlighted the inhalation of allergens from fish, shellfish, seeds, soybeans, cereal grains, hen's egg, cow's milk, and many other foods in allergic reactions. Symptoms have typically included respiratory manifestations such as rhinoconjunctivitis, coughing, wheezing, dyspnea, and asthma. In some cases, anaphylaxis has been observed. In addition, there have been many investigations of occupational asthma following the inhalation of relevant food allergens. This report reviews the current literature focusing on allergic reactions to foods by inhalation.

Food allergy: nuts and tree nuts.

Nuts are a well-defined cause of food allergy, which affect approximately 1 % of the general population in the UK and the USA. There do appear to be differences in the frequency of nut allergy between different countries because of different dietary habits and cooking procedures. For example, in the USA and France, peanuts are one of the most frequent causes of food allergy, but in other countries, it seems to be less common. Genetic factors, in particular, appear to play a role in the development of peanut allergy. While the majority of nut allergens are seed storage proteins, other nut allergens are profilins and pathogenesis-related protein homologues, considered as panallergens because of their widespread distribution in plants. The presence of specific IgE antibodies to several nuts is a common clinical finding, but the clinical relevance of this cross-reactivity is usually limited. Allergic reactions to nuts appear to be particularly severe, sometimes even life-threatening, and fatal reactions following their ingestion have been documented. Food allergy is diagnosed by identifying an underlying immunological mechanism (i.e. allergic testing), and establishing a causal relationship between food ingestion and symptoms (i.e. oral challenges). In natural history investigations carried out in peanut-allergic children, approximately 20 % of the cases outgrew their allergy or developed oral tolerance. The treatment of nut allergies should include patient and family education about avoiding all presentations of the food and the potential for a severe reaction caused by accidental ingestion. Patients and families should be instructed how to recognise early symptoms of an allergic reaction and how to treat severe anaphylaxis promptly.

Unproven diagnostic and therapeutic techniques.

Over the years, there have been many procedures that either have no diagnostic value for any allergic disease or are inappropriate for the diagnosis and treatment of allergy. These procedures fall into the category of unproven diagnostic and therapeutic techniques for allergy. Unfortunately, there are a very limited number of well-controlled investigations examining these various methods. While these tests may provide a superficial appearance of valid test, they have not been shown by controlled clinical trials to be reliable in the diagnosis and treatment of any allergic diseases. After reviewing the data, it is very clear that there is a need for more well-controlled scientific investigations examining all of these techniques. Until that data becomes available for scientific review and critique, these unproven diagnostic and therapeutic techniques should not be used in the evaluation of patients with suspected allergic disease.

Respiratory manifestations of food allergy.

Food allergy may present with a variety of respiratory tract symptoms that generally involve immunoglobulin E antibody-mediated responses. Exposure is typically through ingestion, but in some cases, inhalation of airborne food particles may trigger these reactions. Upper and lower respiratory tract reactions are often a significant component of multisystem, anaphylactic reactions. However, chronic or isolated asthma or rhinitis induced by food is unusual. It is important to recognize that food allergy in early childhood is a marker indicating an increased risk to develop respiratory allergy. The role of food allergy in otitis media is controversial and probably is extremely rare. Likewise, asthmatic responses to food additives can occur but are uncommon. Studies using blinded oral food challenges have demonstrated that foods can elicit airway hyperreactivity and asthmatic responses. Therefore, an evaluation for food allergy should be considered in patients who are at risk, including those with recalcitrant or otherwise unexplained acute, severe asthma exacerbations, asthma triggered after ingestion of particular foods, and asthma that is accompanied by other manifestations of food allergy (e.g., anaphylaxis, moderate to severe atopic dermatitis).

Common respiratory manifestations of food allergy: a critical focus on otitis media.

Previous investigations have established the pathogenic role of food allergy in respiratory tract symptoms, which rarely occur in isolation. Specific foods have been implicated in these reactions. The role of food allergy in otitis media is controversial, probably uncommon, and further studies are needed. Food-induced asthma is more common in young pediatric patients, especially those with atopic dermatitis. Asthma induced by food allergy is considered a risk factor for fatal and near-fatal anaphylactic reactions. Moreover, food allergy can elicit airway hyperreactivity and asthmatic responses. Therefore, evaluation for food allergy should be considered among patients with recalcitrant or otherwise unexplained acute severe asthma exacerbations; asthma triggered by ingestion of particular foods; and asthma and other manifestations of food allergy (eg, anaphylaxis, moderate to severe atopic dermatitis).