Anaphylaxis Conundrum: A Trojan Horse Phenomenon

Wilderness Medical Society Clinical Practice Guidelines on Anaphylaxis

The Wilderness Medical Society convened a panel to review the literature and develop evidence-based clinical practice guidelines on the treatment of anaphylaxis, with an emphasis on a field-based perspective. The review also included literature regarding the definition, epidemiology, clinical manifestations, and prevention of anaphylaxis. The increasing prevalence of food allergies in the United States raises concern for a corresponding rise in the incidence of anaphylaxis. Intramuscular epinephrine is the primary treatment for anaphylaxis and should be administered before adjunctive treatments such as antihistamines, corticosteroids, and inhaled β agonists. For outdoor schools and organizations, selecting a method to administer epinephrine in the field is based on considerations of cost, safety, and first responder training, as well as federal guidelines and state-specific laws.

The Role of Food Challenges in Clinical Practice

Food challenges are the criterion standard for establishing the presence or absence of food allergy. However, they remain underused because of their resource-intensive nature, inadequate reimbursement, and concern for the risk of anaphylaxis. Here, we review indications for performing food challenges, including scenarios of uncertain diagnosis, quality-of-life effects following food challenges, and the impact on office practice including coding and reimbursement issues. Demand for food challenges is likely to increase and allergists should be capable of providing this service to their patients when indicated.

Food-Induced Anaphylaxis: Role of Hidden Allergens and Cofactors

Food anaphylaxis is on the increase, with those who have an allergy to peanuts, tree nuts, milk, and seafood at the highest risk of developing such a reaction. However, the diet in many societies is increasingly varied, much of the food consumed is prepared outside the home, and meals are often composed of many different ingredients. Anaphylaxis may occur to a composite food, and it may be unclear whether the reaction is due to contamination or to a culprit allergen present in an added ingredient. Composite foods can contain many allergic proteins present in small amounts, which do not always have to be labeled, unless they feature in European or US labeling regulations. These "hidden" allergens include mustard, celery, spices, lupine, pea, natural food colourings, and preservatives, but can occasionally include allergenic material from contaminants such as cereal mites. Hidden allergens can provoke severe reactions to seemingly unconnected foods which might then lead to a diagnosis of idiopathic anaphylaxis. The same problem can arise with two well-known types of food allergy; wheat-dependant exercise induced anaphylaxis and allergy to non-specific Lipid Transfer Protein allergens, both of which might only manifest when linked to a cofactor such as exercise. Many of these risk factors for food anaphylaxis have a common link; the public's engagement with popular concepts of health and fitness. This includes the development of a food and exercise culture involving the promotion and marketing of foods for their health-giving properties i.e., meat substitutes, wheat substitutes, supplements and alternative, or "natural" remedies for common ailments. Some of these foods have been reported as the cause of severe allergic reactions, but because they are often viewed as benign unlikely causes of severe allergic reactions, could be considered to be hidden allergens. The best resource to elicit the likelihood of a hidden allergen provoking an allergic reaction is to take a detailed history of the allergic reaction, presence of co-factors, foods suspected, type of food and where it was consumed. A good knowledge of commonly used ingredients, and list of potential hidden allergen suspects are essential tools for the food allergy detective.

Epinephrine Auto-Injectors for Anaphylaxis Treatment in the School Setting: A Discussion Paper

Introduction:Anaphylaxis is a serious, life-threatening systemic allergic reaction that may occur in individuals not previously diagnosed with an allergy. Emergency first-line treatment of choice for acute anaphylaxis is intramuscular administration of epinephrine via an auto-injector. In the school setting, students with known allergies typically keep or carry an epinephrine auto-injector (EAI). For students who do not have a known allergy or for those whose personal EAIs are unavailable, an anaphylactic event could have serious adverse outcomes if an EAI is not available via an undesignated stock supply in the school.

Methods:We searched the published literature from 2000 through 2018 in CINAHL, MEDLINE, and PubMed using the following search terms: anaphylaxis, school setting, epinephrine auto-injector, and food allergies. Throughout this article, undesignated stock EAIs, stock EAIs, EAI stock, and open-order EAIs are used interchangeably.

Conclusion:Anaphylaxis is increasing worldwide as the incidence of food allergies increases. Although stock EAIs for students in schools can have important benefits, the availability of EAIs in the school setting is limited. Barriers to undesignated stock EAIs include the lengthy administrative process for developing school policies and protocols; gaps in nurses' self-perceived knowledge versus objective knowledge on the topic of anaphylaxis; limited resources in many school districts; and complex role demands, lack of confidence in trained staff, or insufficient school nurse staffing. It is important that epinephrine be readily available in schools. Barriers to facilitating stock EAIs include those that can be addressed directly by nurses and those that may require policy changes. Nurses, particularly those working in school settings or pediatrics, could take the lead in discussions about the benefits of stock EAIs in schools, advocating for policy changes as warranted. Fully informed nurses can be better prepared to serve as advocates in ensuring that EAIs are available in school settings.

The Journal of Allergy and Clinical Immunology: In Practice 2017 Year in Review

An impressive number of clinically impactful studies and reviews were published in The Journal of Allergy and Clinical Immunology: In Practice in 2017. As a service to our readers, the editors provide this Year in Review article to highlight and contextualize the advances published over the past year. We include information from articles on asthma, allergic rhinitis, rhinosinusitis, immunotherapy, atopic dermatitis, contact dermatitis, food allergy, anaphylaxis, drug hypersensitivity, urticarial/angioedema, eosinophilic disorders, and immunodeficiency. Within each topic, epidemiologic findings are presented, relevant aspects of prevention are described, and diagnostic and therapeutic advances are enumerated. Treatments discussed include behavioral therapy, allergen avoidance therapy, positive and negative effects of pharmacologic therapy, and various forms of immunologic and desensitization management. We hope this review will help readers consolidate and use this extensive and practical knowledge for the benefit of patients.

Hidden Causes of Anaphylaxis

PURPOSE OF REVIEW

This study aimed to review important hidden causes of anaphylaxis in ingestants, non-ingestants, and uncommon settings.

RECENT FINDINGS

Multiple new and elusive causes of anaphylaxis have been described over the past 35 years. Further research is required to identify the epidemiology, pathophysiology, and clinical impact of these hidden causes. Although these culprits should be considered in the appropriate clinical scenarios, many remain exceedingly rare.