International Study of Risk-Mitigating Factors and In-Flight Allergic Reactions to Peanut and Tree Nut

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

How Common Are Allergic Reactions During Commercial Flights? A Systematic Review and Meta-Analysis

BACKGROUND

Global passenger demand for air travel has increased by over 7% annually since 2006, with a strong recovery following the coronavirus disease 2019 (COVID-19) pandemic. Prior to COVID-19, individuals with food allergies reported significant concern and anxiety over the risk of reactions when travelling by air. However, published data of in-flight medical events (IMEs) due to allergic reactions are limited.

OBJECTIVE

To undertake a systematic review with meta-analysis to estimate the incidence of IMEs due to allergic reactions on commercial flights.

METHODS

We searched MEDLINE, Embase, PsycINFO, and TRANSPORT databases and the Cochrane Register of Controlled Trials for relevant studies reporting IMEs of allergic etiology, published since 1980. Data were extracted in duplicate for meta-analysis, and risk of bias assessed.

STUDY REGISTRATION

PROSPERO CRD42022384341.

RESULTS

Seventeen studies met the inclusion criteria. At meta-analysis, a pooled estimate of 2.2% (95% confidence interval [95% CI] 1.6%-3.1%) of IMEs are coded as being due to allergic reactions. This may be higher in children (3.1%; 95% CI 1.5%-6.6%). The incidence of allergic IMEs at meta-analysis was 0.7 events per million passengers (95% CI 0.4-1.1). Reassuringly, the rate of allergic IMEs has been stable over the past 30 years, despite increasing passenger numbers and food allergy prevalence.

CONCLUSIONS

Allergic reactions coded as IMEs during commercial air travel are uncommon, occurring at an incidence approximately 10 to 100 times lower than that reported for accidental allergic reactions to food occurring in the community. Despite increasing passenger numbers and food allergy prevalence, the rate of allergic IMEs has not changed over the past 3 decades.

The frequency and characteristics of epinephrine use during in-flight allergic events

BACKGROUND

Allergic reactions account for 2% to 4% of medical events in-flight and 5.5% of all medical events in passengers 18 years and under.

OBJECTIVE

To evaluate the incidence of in-flight allergic events including availability, use of epinephrine, and final patient outcome.

METHODS

We conducted a retrospective study of the ground-based medical service (GBMS) database from January 2017 to December 2019 for all allergic events and epinephrine utilization.

RESULTS

A total of 140,579 in-flight medical events (IFMEs) were initially retrieved from the period between January, 2017 and December, 2019, of which 4230 (3.0%) unique cases were identified as allergic events. Epinephrine administration was recommended in 398 passengers by GBMS. Of those, 328 (82.4%) ultimately received at least 1 dose of epinephrine. In multivariate analysis, there was a significant difference in the involvement of volunteers (odds ratio [OR], 3.19; P value < .001; 95% confidence interval [CI], 2.43-4.16), availability of autoinjectors (OR, 2; P value < .001; 95% CI, 1.55-2.58), flight diversion (OR, 11.21; P value < .001; 95% CI, 3.60-34.89), and hospital transport (OR, 6.58; P value < .001; 95% CI, 4.62-9.38) between the 2 groups. Passengers older than 12 years of age were at a higher risk for epinephrine administration. In the secondary analysis of 51 airlines that consistently use GBMS for all IFMEs, the incidence of allergic events was found to be 0.91 cases per million passengers. The incidence of severe in-flight allergic emergencies requiring epinephrine administration was 0.08 cases per million passengers or 12.5 million passengers for 1 event.

CONCLUSION

IFME requiring epinephrine administration is rare with an incidence rate of 1 event in 12.5 million passengers. The risk for epinephrine administration is higher in passengers more than 12 years of age and is associated with significantly higher flight diversion, hospital transport, and involvement of medical volunteers.

The global burden of illness of peanut allergy: A comprehensive literature review

Peanut allergy (PA) currently affects approximately 2% of the general population of Western nations and may be increasing in prevalence. Patients with PA and their families/caregivers bear a considerable burden of self‐management to avoid accidental peanut exposure and to administer emergency medication (adrenaline) if needed. Compared with other food allergies, PA is associated with higher rates of accidental exposure, severe reactions and potentially fatal anaphylaxis. Approximately 7%–14% of patients with PA experience accidental peanut exposure annually, and one‐third to one‐half may experience anaphylaxis, although fatalities are rare. These risks impose considerably high healthcare utilization and economic costs for patients with PA and restrictions on daily activities. Measures to accommodate patients with PA are often inadequate, with inconsistent standards for food labelling and inadequate safety policies in public establishments such as restaurants and schools. Children with PA are often bullied, resulting in sadness, humiliation and anxiety. These factors cumulatively contribute to significantly reduced health‐related quality of life for patients with PA and families/caregivers. Such factors also provide essential context for risk/benefit assessments of new PA therapies. This narrative review comprehensively assessed the various factors comprising the burden of PA.

Management of Peanut Allergy

Peanut allergy is a growing public health concern in westernized countries. Peanut allergy is characterized as an often severe and lifelong allergy, which can have detrimental effects on quality of life and trigger anxiety. Although multiple therapeutic options are emerging, the focus of current management strategies is strict peanut avoidance and carriage of self-injectable epinephrine. The greatest risk of reacting to peanut comes from direct ingestion, whereas casual skin contact or airborne exposure is highly unlikely to provoke significant symptoms. Patients and families must be educated about how to best execute strict peanut avoidance through careful label reading as well as how to understand and address likely and unlikely risk with regard to peanut exposure in public, in particular when dining outside of the home and for children attending school or child care. This review discusses the risk of exposure in public such as at school or on an airplane and how such risk can be abated, situations and scenarios when dining out of the house that may pose more risks than others, the essentials of US and EU label reading laws with particular emphasis on precautionary labeling and the risk implied by such, quality of life and psychosocial issues that may affect the peanut allergic individual and family, and a discussion of how risk may differ and evolve based on the patient's age.

Environmental exposure to peanut and the risk of an allergic reaction

OBJECTIVE

To review the evidence of the risk of environmental exposure to peanut to a peanut allergic individual.

DATA SOURCES AND STUDY SELECTION

A narrative review was performed using a PubMed search of relevant articles involving peanut environmental distribution, environmental peanut abatement, and public policy regarding peanut restriction.

RESULTS

Data from 4 studies have shown that peanut butter vapors and smeared peanut butter on skin do not cause systemic reactions, that peanut can be abated from hands and surfaces using appropriate cleaning agents, and that shelled peanut dust does not become airborne. Studies have recently confirmed dose of 1.5 mg of peanut protein would be generally tolerated by approximately 95% of the peanut-allergic population based on objective symptoms in challenge-based studies, affirming earlier research. Restrictive policies that focus on bans (or restricted presence in certain areas) of peanuts or peanut-containing products in environments such as schools or on commercial aircraft are not backed by evidence that such measures work, which may raise an uncomfortable clash between accommodations that lack any medical evidence of necessity and a desire to provide measures that comfort our patients.

CONCLUSION

There is little risk posed from non-oral exposure to peanut in the environment, from casual contact, proximity, or inhalation. If 5% of the population may tolerate a threshold of approximately 1.5 mg of peanut protein, this may help liberate behavior and situational-decision making regarding the necessity of certain avoidances and restrictions. Continued work is needed to dispel myths about the mechanisms of how peanut may induce an allergic reaction.

In-flight allergic emergencies

Allergic and hypersensitivity reactions such as anaphylaxis and asthma exacerbations may occur during air travel. Although the exact incidence of in-flight asthma and allergic emergencies is not known, we have concerns that this subject has not received the attention it warrants. There is a need to provide passengers at risk and airlines with the necessary measures to prevent and manage these emergencies. A review of the epidemiology, management and approaches to prevention of allergic and asthma emergencies during air travel is presented with the goal of increasing awareness about these important, potentially preventable medical events.

Travel Medical Kit

"The traveler's medical kit is an essential tool for both the novice and expert traveler. It is designed to treat travel-related illness and injury and to ensure preexisting medical conditions are managed appropriately. Travelers are at increased risk for common gastrointestinal issues during travel. Respiratory illnesses make up approximately 8% of the ailments present in returned international travelers. Approximately 12% of travelers experience a travel-related skin condition. First aid treatment for minor injuries is essential to all travel medical kits. The complexity ranges from a small, simple case for the urban traveler to a larger, extensive case for wilderness travel."

Clinical management of food allergy

Food allergies are commonly seen by the practitioner, and managing these patients is often challenging. Recent epidemiologic studies report that as many as 1 in 13 children in the United States may have a food allergy, which makes this an important disease process to appropriately diagnose and manage for primary care physicians and specialists alike. Having a understanding of the basic immunologic processes that underlie varying presentations of food-induced allergic diseases will guide the clinician in the initial workup. This review will cover the basic approach to understanding the immune response of an individual with food allergy after ingestion and will guide the clinician in applying appropriate testing modalities when needed by conducting food challenges if indicated and by educating the patient and his or her guardian to minimize the risk of accidental ingestion.

Developing therapies for peanut allergy

Peanut allergy is an IgE-mediated, persisting immune disorder that is of major concern worldwide. Currently, no routine immunotherapy is available to treat this often severe and sometimes fatal food allergy. Traditional subcutaneous allergen immunotherapy with crude peanut extracts has proven not feasible due to the high risk of severe systemic side effects. The allergen-specific approaches under preclinical and clinical investigation comprise subcutaneous, oral, sublingual and epicutaneous immunotherapy with whole-peanut extracts as well as applications of hypoallergenic peanut allergens or T cell epitope peptides. Allergen-nonspecific approaches include monoclonal anti-IgE antibodies, TCM herbal formulations and Toll-like receptor 9-based immunotherapy. The potential of genetically engineered plants with reduced allergen levels is being explored as well as the beneficial influence of lactic acid bacteria and soybean isoflavones on peanut allergen-induced symptoms. Although the underlying mechanisms still need to be elucidated, several of these strategies hold great promise. It can be estimated that individual strategies or a combination thereof will result in a successful immunotherapy regime for peanut-allergic individuals within the next decade.

Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2013

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2013. Studies on food allergy suggest that (1) 7.6% of the US population is affected, (2) a "healthy" early diet might prevent food allergy, (3) the skin might be an important route of sensitization, (4) allergen component testing might aid diagnosis, (5) the prognosis of milk allergy might be predictable through early testing, (6) oral or sublingual immunotherapy show promise but also have caveats, and (7) preclinical studies show promising alternative modes of immunotherapy and desensitization. Studies on eosinophilic esophagitis show a relationship to connective tissue disorders and that dietary management is an effective treatment for adults. Markers of anaphylaxis severity have been determined and might inform potential diagnostics and therapeutic targets. Insights on serum tests for drug and insect sting allergy might result in improved diagnostics. Genetic and immune-mediated defects in skin epithelial differentiation contribute to the severity of atopic dermatitis. Novel management approaches to treatment of chronic urticaria, including use of omalizumab, are being identified.