Anaphylaxis in the young adult population

Food allergies on a college campus

There are limited data on food allergies among college students. In this article, we review the most current available studies. These self-reported surveys and qualitative interviews reported overall poor avoidance of known allergens and low rates of carrying self-injectable epinephrine among students with food allergy. College students may exhibit risk-taking food behaviors due to a number of factors, including age-appropriate risk-taking predilection, strong social influences, and lack of experience in self-advocacy. Having to disclose an otherwise invisible condition repeatedly in a new environment may also lead to "disclosure fatigue," creating an additional barrier to self-advocacy. Common themes in the narrative include hypervigilance, stigma management, and concern about others' misunderstanding of food allergy. Although there is a paucity of data in this area, it is likely that having greater support at the institution level, along with support from peers and faculty, may help improve awareness, self-injectable epinephrine carriage, and allergen avoidance. This review also discusses strategies for preparedness at school, including specific steps to maximize safety.

IgE and anaphylaxis specific to the carbohydrate alpha-gal depend on IL-4

BACKGROUND

Alpha-gal (Galα1-3Galβ1-4GlcNAc) is a carbohydrate with the potential to elicit fatal allergic reactions to mammalian meat and drugs of mammalian origin. This type of allergy is induced by tick bites, and therapeutic options for this skin-driven food allergy are limited to the avoidance of the allergen and treatment of symptoms. Thus, a better understanding of the immune mechanisms resulting in sensitization through the skin is crucial, especially in the case of a carbohydrate allergen for which underlying immune responses are poorly understood.

OBJECTIVE

We aimed to establish a mouse model of alpha-gal allergy for in-depth immunologic analyses.

METHODS

Alpha-galactosyltransferase 1-deficient mice devoid of alpha-gal glycosylations were sensitized with the alpha-gal-carrying self-protein mouse serum albumin by repetitive intracutaneous injections in combination with the adjuvant aluminum hydroxide. The role of basophils and IL-4 in sensitization was investigated by antibody-mediated depletion.

RESULTS

Alpha-gal-sensitized mice displayed increased levels of alpha-gal-specific IgE and IgG1 and developed systemic anaphylaxis on challenge with both alpha-gal-containing glycoproteins and glycolipids. In accordance with alpha-gal-allergic patients, we detected elevated numbers of basophils at the site of sensitization as well as increased numbers of alpha-gal-specific B cells, germinal center B cells, and B cells of IgE and IgG1 isotypes in skin-draining lymph nodes. By depleting IL-4 during sensitization, we demonstrated for the first time that sensitization and elicitation of allergy to alpha-gal and correspondingly to a carbohydrate allergen is dependent on IL-4.

CONCLUSION

These findings establish IL-4 as a potential target to interfere with alpha-gal allergy elicited by tick bites.

Eruption of Permanent Teeth As Risk Factor for Allergic Reactions During Oral Immunotherapy

Background: Oral immunotherapy (OIT) increases the threshold of reaction in children older than 4 years with food allergy. The risk for severe allergic reactions (ARs) during OIT has been reported in several studies, often in the presence of concomitant cofactors such as physical exercise, empty stomach, medications, poorly controlled asthma, menses, and alcohol consumption. Cases Presentation: We describe a case series of 5 scholar age patients undergoing OIT who showed ARs to a known, previously tolerated dose of allergen during permanent tooth eruption, in which other known cofactors were excluded. Conclusions: Patients may be exposed to cofactors due to behavioral habits not only in the second and third decades of life, but also in the first decade of life, due to the timing of mixed dentition. More studies are needed to estimate the frequency and entity of tooth eruption as cofactor, as well as to know the correct management of children undergoing dentition during OIT.

Food Allergy Management for Adolescents Using Behavioral Incentives: A Randomized Trial

OBJECTIVE

We sought to evaluate the use of behavioral economics approaches to promote the carrying of epinephrine auto-injectors (EAIs) among adolescents with food allergies. We hypothesized that adolescents who receive frequent text message nudges (Intervention 1) or frequent text message nudges plus modest financial incentives (Intervention 2) would be more likely to carry their epinephrine than members of the usual care control group.

METHODS

We recruited 131 adolescents ages 15 to 19 with a food allergy and a current prescription for epinephrine to participate in a cohort multiple randomized controlled trial. Participants were randomly assigned to participate in Intervention 1, Intervention 2, or to receive usual care. The primary outcome was consistency of epinephrine-carrying, measured as the proportion of checkpoints at which a participant could successfully demonstrate they were carrying their EAI, with photo-documentation of the device.

RESULTS

During Intervention 1, participants who received the intervention carried their EAI 28% of the time versus 38% for control group participants (P = .06). During Intervention 2, participations who received the intervention carried their EAI 45% of the time versus 23% for control group participants (P = .002).

CONCLUSIONS

Text message nudges alone were unsuccessful at promoting EAI-carrying but text message nudges combined with modest financial incentives almost doubled EAI-carriage rates among those who received the intervention compared with the control group. However, even with the intervention, adolescents with food allergies carried their EAI <50% of the time. Alternative strategies for making EAIs accessible to adolescents at all times should be implemented.

Appearance of food-dependent exercise-induced anaphylaxis as an inflammatory disease: a pediatric case report and differential diagnosis

Anaphylaxis is the most serious of all allergic reactions. Despite advances in the knowledge of anaphylaxis, its clinical manifestations continue to be under-recognized. Indeed, proper diagnosis of anaphylaxis is often missed, and the treatment is delayed. The underlying causes are still under investigation globally. Inflammation represents the cornerstone of pathophysiology of anaphylaxis. Food-dependent exercise-induced anaphylaxis (FDEIA) is a rare clinical manifestation characterized by a chronological sequence in which food ingestion followed by physical exercise leads to anaphylaxis. Its mechanisms are yet to be fully explained. We report the case of a 14-year-old Chinese male who lost consciousness while undergoing physical activity at school. Several differential diagnoses were considered such as hypovolemic shock, septic shock, anaphylactic shock or neurological adverse event. Finally, the diagnosis of FDEIA was made. This case highlights the difficulties in diagnosing FDEIA and its management, especially when the clinical history is not complete and detailed.

An International First: Stakeholder Consensus Statement for Food Allergen Management in Packaged Foods and Food Service for Australia and New Zealand

Food-allergic consumers encounter inadequate, confusing, and ambiguous allergen information for packaged and unpackaged foods. Key Australian and New Zealand allergy organizations convened multiple forums to facilitate discussions among consumers, food manufacturers, food retailers, regulatory bodies, researchers, and health professionals to develop a unified approach to improving food allergen management. The following stakeholder consensus statement provides a foundation for advocacy for improved food allergen management and safety. It is the responsibility of consumers to: 1. declare their food allergies and read food labels (including ingredient lists and allergen declaration statements), and 2. ultimately make their own judgment about the foods they choose to consume. We consider that to enable consumers to make informed decisions about their safety, It is the responsibility of packaged food manufacturers to: 1. follow robust allergen management practices including quantitative risk assessment, and 2. use clear, consistent labeling to inform consumers about that food's allergen content, including the possible presence of unintended allergens. It is the responsibility of food service establishments and providers to: 1. follow robust allergen management practices, and 2. ensure that staff understand and can inform consumers about the allergen content of the food they provide, including the possible presence of unintended allergens.

A multicenter anaphylaxis registry in Korea: Clinical characteristics and acute treatment details from infants to older adults

Background

Although the prevalence of anaphylaxis is increasing worldwide, the large-scale studies in Asia evaluating anaphylaxis in all age groups are limited. We aimed to collect more precise and standardized data on anaphylaxis in Korea using the first multicenter web-based registry.

Methods

Twenty-two departments from 16 hospitals participated from November 2016 to December 2018. A web-based case report form, designed by allergy specialists, was used to collect anaphylaxis data.

Results

Within the 2-year period, 558 anaphylaxis cases were registered. The age of registered patients ranged from 2 months to 84 years, and 60% were aged <18 years. In children and adolescents, foods (84.8%) were the most common cause of anaphylaxis, followed by drugs (7.2%); in adults, drugs (58.3%) were the most common cause, followed by foods (28.3%) and insect venom (8.1%). The onset time was ≤10 min in 37.6% of patients. Among the 351 cases registered via the emergency department (ED) of participating hospitals, epinephrine was administered to 63.8% of patients. Among those receiving epinephrine in the ED, 13.8% required 2 or more epinephrine shots. Severe anaphylaxis accounted for 23.5% cases (38.1% in adults; 13.7% in children); patients with drug and insect venom-induced anaphylaxis had higher rates of severe anaphylaxis.

Conclusion

This multicenter registry provides data on anaphylaxis for all age groups for the first time in Asia. The major causes and severity of anaphylaxis were remarkably different according to age group, and the acute treatment features of anaphylaxis in the EDs were examined in detail.

Food Allergy Management at School

BACKGROUND

Approximately 8% of schoolchildren in the United States experience potentially life-threatening food allergies. They must diligently avoid allergenic foods and have prompt access to epinephrine to treat anaphylaxis. These prevention strategies must be sustained without interruption, posing a range of challenges at school.

METHODS

We conducted semi-structured interviews with 178 participants about their experiences managing food allergies outside the home. Interviews were transcribed and analyzed using an iterative approach in NVivo 10.

RESULTS

Participants reported highly varied school experiences across the ecological model. They described the need to be proactive and self-sufficient to manage food allergies. Whereas food allergy-related social exclusion was common, participants also described positive peer interactions, including intensive peer engagement and support. They perceived that formal school policies were limited in scope and inconsistently implemented. Prevention-oriented policies were more common in lower grades than in higher grades.

CONCLUSIONS

Poorly defined and implemented policies disrupted students' social and educational experiences at school, families' relationships with school staff, and, ultimately, the safety and wellbeing of students with allergies. Given the high prevalence of food allergies among children, these findings demonstrate the need for multiple layers of support to facilitate safe, socially inclusive food allergy management at schools.

Idiopathic anaphylaxis: What you do not know may hurt you

Idiopathic anaphylaxis (IA), like immunologic and nonimmunologic anaphylaxis, is a life-threatening, sometimes fatal allergic disease. Although the priority is immediate recognition and initiation of treatment, long-term care planning is important to help reduce anxiety and promote healthy growth and development. Learning to recognize, manage, and stabilize the child is an essential part of improving the family dynamics. Despite advancements in the management of anaphylaxis, research has shown a need for continued patient education and training to improve timely recognition and treatment. This article focuses on elucidating the clinical presentation, theories of pathogenesis, and diagnosis, treatment, and management of IA.

Emergency Call Characteristics and EMS Dispatcher Protocol Adherence for Possible Anaphylaxis

Objective: Anaphylaxis is a medical emergency requiring prompt recognition and treatment with intramuscular epinephrine to optimize outcomes. To date, there is a paucity of data regarding the demographic characteristics of the subset of patients calling 9-1-1 for allergic reactions and the emergency medical services (EMS) dispatcher's adherence to national protocols for their response to a suspected allergic reaction. Methods: We conducted a retrospective review of dispatch calls to a local municipality that were dispatched with an impression of an "allergic reaction" or "difficulty breathing related to a suspected allergic reaction" from January 2016 to June 2016. Using a modified Delphi approach, the voice recordings of the calls were reviewed for EMS dispatcher adherence to the Medical Priority Dispatch System v12.2 (2012) triage questions and pre-arrival instructions for the Allergies/Envenomations and Breathing Problems protocols. The calls were further reviewed for demographic characteristics, symptomatology, history of allergy, suspected trigger of the current reaction, and use and availability of medications. Calls were also classified as to whether the patient met criteria for anaphylaxis. We calculated frequencies for categorical measures and medians with ranges for continuous measures. Results: A total of 146 calls met inclusion criteria. The median age of patients was 29 years (interquartile range 13, 52). 12.3% (n = 18) of the calls reviewed were consistent with national standards for anaphylaxis. Food was the most commonly reported historical allergy, whereas medication accounted for the most commonly suspected trigger for the current symptoms. The EMS dispatcher asked about alertness, difficulty breathing, difficulty speaking, and color change in 39.7, 80.1, 12.3, and 2.7% of calls, respectively. While 56.2% of dispatchers inquired about a history of severe allergy, only 16.4% inquired about prescribed special injections. Conclusions: The majority of calls were not consistent with anaphylaxis, and EMS dispatchers rarely strictly followed the Medical Priority Dispatch System guidelines aimed at identifying anaphylaxis. Future studies would be beneficial to determine if our findings hold true in other EMS service areas.

The Epidemiology of Anaphylaxis

Anaphylaxis is a dramatic expression of systemic allergy. The lifetime prevalence of anaphylaxis is currently estimated at 0.05-2 % in the USA and ~3 % in Europe. Several population-specific studies have noted a rise in the incidence, particularly in the hospitalizations and ER visits due to anaphylaxis. The variable signs and symptoms that constitute the diagnostic criteria for anaphylaxis, the differences in diagnostic algorithms, and the limitations in the current coding systems have made summarizing epidemiologic data and comparing study results challenging. Nevertheless, across all studies, the most common triggers continue to be medications, food, and venom. Various risk factors for more severe reactions generally include older age, history of asthma, and having more comorbid diseases. Interesting seasonal, geographic, and latitude differences have been observed in anaphylaxis prevalence and incidence rates, suggesting a possible role of vitamin D and sun exposure in modifying anaphylaxis risk. While the incidence and prevalence of anaphylaxis appear to be increasing in certain populations, the overall fatality rate remains relatively low.

Student and Parent Perspectives on Severe Food Allergies at College

INTRODUCTION

Constant vigilance to manage severe food allergies (FAs) can lead to high stress. Additional stress may develop during life-course transitions, such as the transition to college. However, few studies have evaluated everyday and FA-related stress in college students with FA and their parents. This analysis examined experiences of 26 college students with FA and their parents.

METHODS

Students and parents completed online surveys in a mixed-methods exploratory study of everyday and FA-related stressors, potential contributing factors, and FA management.

RESULTS

FA affected nearly all areas of students' lives. Management required constant vigilance because of issues of trust in others. However, nearly 40% of students did not consistently carry emergency medication to counteract reactions. Parents worried from a distance while learning to trust their child's FA management capabilities.

DISCUSSION

Additional preparation and support for college students with severe FA and their parents may help improve stress and FA management.

Anaphylaxis to foods in a population of adolescents: incidence, characteristics and associated risks

BACKGROUND

Information about severe reactions to foods in adolescence is limited.

OBJECTIVE

To describe reactions to foods, including anaphylaxis, with regard to incidence, characteristics and associated risks, among 16-year-olds (adolescents) in a large, population-based birth cohort.

METHODS

Parent-reported questionnaire data from ages 2-3 months, and 1, 2 and 16 years were used (N = 3153). Anaphylaxis at age 16 years was defined per NIAID/FAAN criteria. Immunoglobulin E (IgE) antibodies to 14 common food and inhalant allergens were analysed at ages 4 (n = 2283) and 16 years (n = 2510). Among adolescents with food-related symptoms (FRS) and for whom blood was available (n = 221), 25 additional food allergen extracts or allergen components were analysed. Associations between reactions to foods, and sensitization and allergic multimorbidity were investigated.

RESULTS

In the 12 months prior to the 16-year assessment, 8.5% of adolescents had FRS. This included 0.8% (n = 24) adolescents who were classified as having anaphylaxis, yielding an incidence rate of 761/100 000 person-years. One-third of adolescents accessed health care during anaphylaxis. Allergic multimorbidity in infancy, as well as sensitization to foods and airborne allergens at age 4 years, was associated with an increased risk for FRS in adolescence. Peanuts and tree nuts were the most common culprit foods for anaphylaxis, and fruits and vegetables for non-anaphylactic reactions. Adolescents with anaphylaxis were significantly more likely to be sensitized to storage proteins (Ara h 2, Cor a 9, Cor a 14) and to be polysensitized to foods (P < 0.001 vs. non-anaphylactic reactions).

CONCLUSIONS AND CLINICAL RELEVANCE

The incidence of food-induced anaphylaxis during adolescence in our population-based birth cohort is higher than previously reported. Adolescents with anaphylaxis differ from adolescents with non-anaphylactic FRS with regard to culprit foods and sensitization. Adolescents with previous anaphylaxis are likely to be polysensitized to foods, particularly tree nut and peanut storage proteins, and which warrants consideration at follow-up.

Children Covered by Medicaid/State Children's Health Insurance Program More Likely to Use Emergency Departments for Food Allergies

BACKGROUND

Food allergies (FAs) occur in 4% to 8% of children in the United States, and emergency department (ED) visits account for up to 20% of their costs. In 2010, the National Institute of Allergy and Infectious Diseases established diagnostic criteria and management practices for FAs, and recognition and treatment of FAs for pediatric ED practitioners has been described.

OBJECTIVE

This study identified trends and factors related to ED visits for pediatric FAs in the United States from 2001 to 2010. It was hypothesized that FAs increased and that differences existed in ED utilization based on age, insurance status, and geography. Low concordance with treatment guidelines for FAs was expected.

METHODS

Multivariate logistic regression, using National Hospital Ambulatory Medical Care Survey data, estimated factors associated with ED visits and treatment of FAs and nonspecific allergic reactions. Trends and treatment patters used weighted frequencies to account for the complex 4-stage probability survey design.

RESULTS

An estimated 239,303 (95% confidence interval [CI], 180,322-298,284) children visited the ED for FAs, demonstrating a significant rate increase during the period (53.08, P < 0.001). Logistic regression showed that the odds of ED visits for FAs were significantly associated with Medicaid/State Children's Health Insurance Program insurance (OR, 1.65 [95% CI, 1.01-2.69], P = 0.04), adolescents (OR, 1.92 [95% CI, 1.10-3.35], P = 0.02), and boys (OR, 1.55 [95% CI, 1.03-2.35], P = 0.04). Treatment with epinephrine for anaphylaxis diagnoses occurred in 57.4% of visits (95% CI, 42.3%-66.8%).

CONCLUSIONS

Medicaid/State Children's Health Insurance Program-insured pediatric patients had higher odds of visiting ED for recognized FAs and nonspecific allergic reactions and higher odds of receiving epinephrine than privately insured children.

Transitioning the Allergy/Immunology Patient from Childhood to Adulthood

Allergic disorders and immunodeficiencies are generally chronic and even lifelong conditions, often changing over time, making the cautious transition of care from childhood to adulthood particularly important. Many, but not all, patients can continue to receive their care from the same physician as they transition through adolescence and emerging adulthood, made possible because allergy/immunology training programs require cross-training in the care of both pediatric and adult patients. Although keeping the same physician makes the transition easier for many allergy/immunology patients, even these patients face psychosocial issues unique to adolescents and emerging adults, including increased autonomy, risk-taking behavior, and medical self-management. Successful transition for patients with chronic allergic and immunologic conditions involves an understanding of the natural history of these conditions by patients and physicians alike, a gradual increase in self-management depending on individual readiness, and careful communication between pediatric and adult specialists as care is transitioned. [Pediatr Ann. 2017;46(6):e229-e234.].

Adverse Medication Reactions

Cutaneous adverse drug reactions (ADRs) are among the most frequent adverse reactions in patients receiving drug therapy. They have a broad spectrum of clinical manifestations, are caused by various drugs, and result from different pathophysiological mechanisms. Hence, their diagnosis and management is challenging.

Severe cutaneous ADRs comprise a group of diseases with major morbidity and mortality, reaching 30 % mortality rate in cases of Toxic Epidermal Necrolysis.

This chapter covers the terminology, epidemiology, pathogenesis and classification of cutaneous ADR, describes the severe cutaneous ADRs and the clinical and laboratory approach to the patient with cutaneous ADR and presents the translation of laboratory-based discoveries on the genetic predisposition and pathogenesis of cutaneous ADRs to clinical management guidelines.

Socioeconomic Disparities in the Economic Impact of Childhood Food Allergy

OBJECTIVES

We compared direct medical costs borne by the health care system and out-of-pocket costs borne by families for children with food allergy by socioeconomic characteristics.

METHODS

We analyzed cross-sectional survey data collected between November 2011 and January 2012 from 1643 US caregivers with a food-allergic child. We used a 2-part regression model to estimate mean costs and identified differences by levels of household income and race or ethnicity.

RESULTS

Children in the lowest income stratum incurred 2.5 times the amount of emergency department and hospitalization costs as a result of their food allergy than higher-income children ($1021, SE ±$209, vs $416, SE ±$94; P < .05). Costs incurred for specialist visits were lower in the lowest income group ($228, SE ±$21) compared with the highest income group ($311, SE ±$18; P < .01) as was spending on out-of-pocket medication costs ($117, SE ± $26, lowest income; $366, SE ±$44, highest income; P < .001). African American caregivers incurred the lowest amount of direct medical costs and spent the least on out-of-pocket costs, with average adjusted costs of $493 (SE ±$109) and $395 (SE ±$452), respectively.

CONCLUSIONS

Disparities exist in the economic impact of food allergy based on socioeconomic status. Affordable access to specialty care, medications, and allergen-free foods are critical to keep all food-allergic children safe, regardless of income and race.

Allocation of food allergy responsibilities and its correlates for children and adolescents

This study examined the degree to which children and adolescents with food allergy accept responsibility for their own care, and the extent to which greater self-management is associated with past history of a life-threatening allergic reaction or anxiety. For children (n = 190), caregiver and patient report of self-management was consistent, but agreement was poor for adolescent dyads (n = 59). History of a life-threatening allergic reaction was associated with greater self-management for children only, while among adolescents, it was associated with greater anxiety. Given that shifting to self-management may be challenging, discussion and preparation about this process is warranted.

Epidemiology of anaphylaxis

Knowledge about the epidemiology of anaphylaxis is based on data from various sources: clinical practice, large secondary clinical and administrative databases of primary care or hospitalized patients, and recent surveys with representative samples of the general population. As several similar results are often reported in several publications and populations, such findings are highly like to be robust. One such finding is that the incidence and prevalence of anaphylaxis are higher than previously thought. Publications from the last 5 years reveal an incidence of between 50 and 112 episodes per 100 000 person-years; estimated prevalence is 0.3-5.1% depending on the rigour of the definitions used. Figures are higher in children, especially those aged 0-4 years. Publications from various geographical areas based on clinical and administrative data on hospitalized patients suggest that the frequency of admissions due to anaphylaxis has increased (5-7-fold in the last 10-15 years). Other publications point to a geographic gradient in the incidence of anaphylaxis, with higher frequencies recorded in areas with few hours of sunlight. However, these trends could be the result of factors other than a real change in the incidence of anaphylaxis, such as changes in disease coding and in the care provided. Based on data from the records of voluntary declarations of death by physicians and from large national databases, death from anaphylaxis remains very infrequent and stands at 0.35-1.06 deaths per million people per year, with no increases observed in the last 10-15 years. Although anaphylaxis can be fatal, recurrence of anaphylaxis--especially that associated with atopic diseases and hymenoptera stings--affects 26.5-54% of patients.

A behavioral economics intervention to encourage epinephrine-carrying among food-allergic adults: a randomized controlled trial

BACKGROUND

Adolescents and young adults with food allergies are at increased risk of adverse events, including death from anaphylaxis. Epinephrine is the cornerstone of emergency response, yet few individuals with serious food allergies consistently carry their emergency medication. Behavioral economics offers promising, previously untapped opportunities for behavior change in this arena.

OBJECTIVE

To test the effectiveness of modest financial incentives in promoting the carrying of epinephrine and to evaluate the acceptability of text messaging for delivering reminders and key health messages to young adults with food allergies.

METHODS

A mixed-methods randomized controlled trial in young adults with food allergies investigated the carrying of epinephrine auto-injectors using financial incentives plus text message reminders vs text message reminders alone. Epinephrine carriage was assessed 10 times during the 49-day intervention using rapid-reply cell phone photographs plus daily code words.

RESULTS

The intervention (financial incentive) group had their epinephrine auto-injectors at 54% of check-ins vs 27% of check-ins in the control (text-only) group (P = .023). Participants in the 2 groups consistently reported favorable impressions of text messaging as a desirable, unobtrusive way to receive information and support for food allergy management.

CONCLUSION

Although the intervention and control groups reported favorable impressions of text message-based reminder systems, the intervention group performed significantly better than the control group on a photograph-based measurement of epinephrine carriage. There remained ample room for improvement in the 2 groups given the goal of consistent, uninterrupted epinephrine carriage by people with potentially life-threatening food allergies.

TRIAL REGISTRATION

https://clinicaltrials.gov; NCT02354729.

Recognition and first-line treatment of anaphylaxis

The International Classification of Diseases (ICD)-9 included a code only for anaphylactic shock. The improved ICD-10 coding defines the different symptoms and types of anaphylaxis and includes coding for anaphylaxis without shock. This new coding is consistent with the efforts of the National Institute of Allergy and Infectious Diseases (NIAID) and the Food Allergy and Anaphylaxis Network (FAAN), who convened a panel to formulate a definition of and the diagnostic criteria for anaphylaxis. Anaphylaxis is a serious reaction that has a rapid onset and may cause death. It is a systemic immunoglobulin E-mediated reaction resulting from the sudden release of multiple mediators from mast cells and basophils. Foods are the most common triggers for anaphylactic reactions, followed by drugs, insect stings, and idiopathic anaphylaxis (anaphylaxis of unknown cause). If the NIAID/FAAN criteria are met and anaphylaxis is diagnosed, epinephrine administration is mandatory. Delays in epinephrine administration have been associated with fatalities. Patients should have ready access to >1 epinephrine autoinjector in the outpatient setting. An individualized emergency action plan should be developed for each patient at risk for anaphylaxis.

Anaphylaxis: underdiagnosed, underreported, and undertreated

Diagnostic criteria and administrative codes for anaphylaxis have evolved in recent years, partly reflecting the challenges in recognizing anaphylaxis and understanding its symptoms. Before the diagnostic criteria were disseminated by the National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network, several studies showed that a substantial proportion of anaphylaxis cases presenting to the emergency department (ED) were not recognized as such. Furthermore, epinephrine, the first-line treatment, was used in fewer than half of cases, especially if anaphylaxis was not diagnosed at the time. Although management practices may have improved since that time, anaphylaxis continues to be underrecognized and undertreated in the US. Of particular concern are findings that the majority of patients who visited the ED for an acute allergic reaction or anaphylaxis were not given a prescription for an epinephrine autoinjector, educated about avoiding the offending allergen, or advised to consult with an allergist. Improvements in the recognition and management of anaphylaxis have the potential to reduce the substantial burden that it currently places on the health care system. The articles in this supplement cover a wide range of issues surrounding anaphylaxis and seek to disseminate information helpful to health care professionals in general and primary care providers in particular.