Anaphylaxis: clinical concepts and research priorities

A Clinical Practice Guideline for the Emergency Management of Anaphylaxis (2020)

Background: For anaphylaxis, a life-threatening allergic reaction, the incidence rate was presented to have increased from the beginning of the 21st century. Underdiagnosis and undertreatment of anaphylaxis are public health concerns. Objective: This guideline aimed to provide high-quality and evidence-based recommendations for the emergency management of anaphylaxis. Method: The panel of health professionals from fifteen medical areas selected twenty-five clinical questions and formulated the recommendations with the supervision of four methodologists. We collected evidence by conducting systematic literature retrieval and using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: This guideline made twenty-five recommendations that covered the diagnosis, preparation, emergency treatment, and post-emergency management of anaphylaxis. We recommended the use of a set of adapted diagnostic criteria from the American National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network (NIAID/FAAN), and developed a severity grading system that classified anaphylaxis into four grades. We recommended epinephrine as the first-line treatment, with specific doses and routes of administration for different severity of anaphylaxis or different conditions. Proper dosage is critical in the administration of epinephrine, and the monitor is important in the IV administration. Though there was only very low or low-quality evidence supported the use of glucocorticoids and H1 antagonists, we still weakly recommended them as second-line medications. We could not make a well-directed recommendation regarding premedication for preventing anaphylaxis since it is difficult to weigh the concerns and potential effects. Conclusion: For the emergency management of anaphylaxis we conclude that: • NIAID/FAAN diagnostic criteria and the four-tier grading system should be used for the diagnosis • Prompt and proper administration of epinephrine is critical.

Is the clinical manifestation of anaphylaxis in children influenced by the trigger of reaction?

INTRODUCTION

The number of anaphylaxis diagnoses in children is rising, being still based on the clinical picture.

AIM

To determine whether triggers of anaphylaxis influence its clinical characteristics in children and adolescents.

MATERIAL AND METHODS

The study group included 114 children (5 months-17 years, mean age: 8.0 ±4.8 years), (66%: boys) with the episode of anaphylaxis up to 1 year back. Medical data were entered to the NORA Registry by means of a validated structured on-line questionnaire.

RESULTS

Three most frequent triggers of anaphylaxis were: insect venom (47.4%), food (35.1%), drugs (5.3%), with a predominance of food (egg white, cow's milk, nuts and peanuts) in the 0-6 years age group, while insect venom (bee predominance) in the 7-17 years age group (p = 0.016). Clinical manifestations differed between food vs. venom allergic reactions and presented as gastro-intestinal (GI) (61.4%) (p = 0.004), respiratory (RS) (93.9%) (p = 0.036), and cardiovascular (CVS) (74.6%) (p = 0.022) symptoms. Among objective symptoms, vomiting was the most common symptom in the 0-2 years age group (47.1%) (p = 0.006), while hypotension in those aged 7-12 years (40%) (p = 0.010). Severity of symptoms evaluated as Mueller's grade (IV - 74.5%) and as Ring and Messmer's grade (III - 65.8%), depended on the trigger (p = 0.028, p = 0.029, respectively). Life-threatening symptoms occurred in 26 children (fall of the blood pressure - 22%, loss of consciousness - 4.4%).

CONCLUSIONS

The clinical manifestation of anaphylaxis in children is both trigger and age dependent, irrespective of the gender. A typical patient with food anaphylaxis was younger, presenting predominantly GI symptoms, while a typical patient with venom anaphylaxis was older, with mostly cardiovascular symptoms.

World allergy organization anaphylaxis guidance 2020

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions. The occurrence of anaphylaxis has increased in recent years, and subsequently, there is a need to continue disseminating knowledge on the diagnosis and management, so every healthcare professional is prepared to deal with such emergencies. The rationale of this updated position document is the need to keep guidance aligned with the current state of the art of knowledge in anaphylaxis management. The World Allergy Organization (WAO) anaphylaxis guidelines were published in 2011, and the current guidance adopts their major indications, incorporating some novel changes. Intramuscular epinephrine (adrenaline) continues to be the first-line treatment for anaphylaxis. Nevertheless, its use remains suboptimal. After an anaphylaxis occurrence, patients should be referred to a specialist to assess the potential cause and to be educated on prevention of recurrences and self-management. The limited availability of epinephrine auto-injectors remains a major problem in many countries, as well as their affordability for some patients.

Fatal Anaphylaxis: Mortality Rate and Risk Factors

Up to 5% of the US population has suffered anaphylaxis. Fatal outcome is rare, such that even for people with known venom or food allergy, fatal anaphylaxis constitutes less than 1% of total mortality risk. The incidence of fatal anaphylaxis has not increased in line with hospital admissions for anaphylaxis. Fatal drug anaphylaxis may be increasing, but rates of fatal anaphylaxis to venom and food are stable. Risk factors for fatal anaphylaxis vary according to cause. For fatal drug anaphylaxis, previous cardiovascular morbidity and older age are risk factors, with beta-lactam antibiotics, general anesthetic agents, and radiocontrast injections the commonest triggers. Fatal food anaphylaxis most commonly occurs during the second and third decades. Delayed epinephrine administration is a risk factor; common triggers are nuts, seafood, and in children, milk. For fatal venom anaphylaxis, risk factors include middle age, male sex, white race, cardiovascular disease, and possibly mastocytosis; insect triggers vary by region. Upright posture is a feature of fatal anaphylaxis to both food and venom. The rarity of fatal anaphylaxis and the significant quality of life impact of allergic conditions suggest that quality of life impairment should be a key consideration when making treatment decisions in patients at risk for anaphylaxis.

Self-medication of anaphylactic reactions due to Hymenoptera stings-an EAACI Task Force Consensus Statement

An anaphylactic reaction due to a Hymenoptera sting is a clinical emergency, and patients, their caregivers as well as all healthcare professionals should be familiar with its recognition and acute management. This consensus report has been prepared by a European expert panel of the EAACI Interest Group of Insect Venom Hypersensitivity. It is targeted at allergists, clinical immunologists, internal medicine specialists, pediatricians, general practitioners, emergency department doctors, and any other healthcare professional involved. The aim was to report the scientific evidence on self-medication of anaphylactic reactions due to Hymenoptera stings, to inform healthcare staff about appropriate patient self-management of sting reactions, to propose indications for the prescription of an adrenaline auto-injector (AAI), and to discuss other forms of medication. First-line treatment for Hymenoptera sting anaphylaxis is intramuscular adrenaline. Prescription of AAIs is mandatory in the case of venom-allergic patients who suffer from mast cell diseases or with an elevated baseline serum tryptase level and in untreated patients with a history of a systemic reaction involving at least two different organ systems. AAI prescription should also be considered in other specific situations before, during, and after stopping venom immunotherapy.

Anaphylaxis audit in a busy metropolitan Emergency Department: a review of real life management compared to best practice

Background

Deficiencies in anaphylaxis management in Emergency Departments is well recognised despite established guidelines for its treatment.

Objective

To identify deficiencies in the management of anaphylaxis in a busy metropolitan Emergency Department and determine if an education intervention could correct these.

Methods

Paediatric and adult admissions to the Emergency Department of a busy hospital were tracked over a 10-month period with a targeted educational program being instituted at 5 months. The electronic records were retrospectively reviewed looking for cases of anaphylaxis and milder forms of immediate type allergic reactions presenting with a combination of urticaria and nonairway threatening angioedema. Anaphylaxis presentation was graded using the Brown grading system. Use of all medication during resuscitation was documented. Observation period before discharge and referral to specialist unit for follow-up was noted.

Results

In the first 5 months, 38 patients fulfilled our criteria. Three had severe anaphylaxis, 13 had moderately severe anaphylaxis and 12 had urticaria and angioedema without anaphylaxis. Anaphylaxis was not always recognised or graded leading to inappropriate management with adrenaline often being withheld. Promethazine, usually given in parenteral form, was frequently administered. Observation time was often inadequate. Referral to an immunologist was not universally followed through. Following the educational intervention 58 patients fulfilled our criteria over the next 5 months. The appropriate use of adrenaline increased by 21% and the use of sedating antihistamines decreased by 16%, while the number of referrals to an immunologist increased by 24%. There was an 11% reduction in the number of patients who were observed for at least 4 hours.

Conclusion

A number of deficiencies in the management of anaphylaxis presentations have been identified. Targeted educational activities aimed at the Emergency Department hospital staff may improve outcomes.

The Sound of a Buk (Korean Traditional Drum) Attenuates Anaphylactic Reactions by the Activation of Estrogen Receptor-β

BACKGROUND

Anaphylaxis is associated with systemic vasodilation that causes low blood pressure and induces hypoxic brain damage. The sound of a Buk (Korean traditional drum) is similar to the human heart beat and affects blood pressure, heart rate, and the nervous system by increasing physiological excitation and sympathetic nervous system activity. So, this study focused on the effect of Buk music as a means of treating anaphylaxis.

METHODS

Mice were given an intraperitoneal injection of compound 48/80 (6.5 mg/kg, a mast cell degranulator). After compound 48/80 injection, mice were exposed to Buk music and white noise for 5 min in a sound isolation booth. The mortality rate was checked over the next 40 min. Levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in the serum and brain tissues were analyzed by Western blotting, quantitative real-time PCR, and ELISA methods.

RESULTS

Exposure to Buk music significantly reduced compound 48/80-induced mortality and histamine release, as well as HIF-1α and VEGF levels compared with the compound 48/80 group or compound 48/80 and white noise group. Buk music also reduced levels of tumor necrosis factor-α, and significantly increased estrogen receptor-β mRNA levels.

CONCLUSION

These results indicate that Buk music has potential for the treatment of anaphylaxis.

Common causes of anaphylaxis in children: the first report of anaphylaxis registry in iran

BACKGROUND

: Anaphylaxis is an acute, systemic, and potentially fatal allergic reaction. Many things can cause anaphylaxis potentially but some agents are more common like some foods (milk, egg, soy, wheat, peanut, tree nut, shellfish, and fish), insect stings, medications, latex, and food-dependent exercise-induced anaphylaxis. The goal of this study is to show the common causes of anaphylaxis among the children with anaphylaxis history who were referred to the Immunology, Asthma and Allergy Research Institute (IAARI) during a 4-year period (2005-2009).

METHODS AND MATERIALS

: During those 4 years, we registered all children (<14 years old) with a history of anaphylactic reaction. To prove the cause of anaphylaxis, we performed skin prick tests with suspected agents according to their history and measured specific IgE against them by the ImmunoCAP test. Recognition of common allergens was based on having a positive history for 1 allergen and positive skin prick test or specific IgE for that at the same time, or having positive results from both tests when the allergen was unclear. Idiopathic anaphylaxis was a reaction when any known allergen and positive tests were not obtained.

RESULTS

: One hundred ninety-three nonfatal anaphylactic attacks among 63 children were recognized. In total, the most current cause of anaphylaxis in children was food (89.7%). Milk (49.3%) and wheat (26.1%) were the most common. Other foods were egg (8.7%), nuts (2.8%), and spices (2.8%). Six children (8.7%) were sensitive to multiple food allergens like milk, egg, and wheat. Five (7.1%) of 63 patients had anaphylactic attack because of stinging. Wasp was the trigger in 3 (4.3%) of them and honeybee was the cause in 1 (1.4%). The last one was because of unknown hymenoptera. There were 2 idiopathic cases of all 63 patients.

CONCLUSIONS

: Food allergens, especially milk and wheat, are the most common cause of anaphylaxis in children. Because anaphylaxis can be fatal, it is advisable to recognize its causes in different communities to prevent recurrent attacks.

Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock

BACKGROUND

Anaphylaxis is a serious hypersensitivity reaction that is rapid in onset and may cause death. Adrenaline is recommended as the initial treatment of choice for anaphylaxis.

OBJECTIVES

To assess the benefits and harms of adrenaline (epinephrine) in the treatment of anaphylaxis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to March 2007), EMBASE (1966 to March 2007), CINAHL (1982 to March 2007), BIOSIS (to March 2007), ISI Web of Knowledge (to March 2007) and LILACS (to March 2007). We also searched websites listing ongoing trials: http://clinicaltrials.gov/, http://www.controlledtrials.com and http://www.actr.org.au/; and contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing adrenaline with no intervention, placebo or other adrenergic agonists were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed articles for inclusion.

MAIN RESULTS

We found no studies that satisfied the inclusion criteria.

AUTHORS' CONCLUSIONS

Based on this review, we are unable to make any new recommendations on the use of adrenaline for the treatment of anaphylaxis. Although there is a need for randomized, double-blind, placebo-controlled clinical trials of high methodological quality in order to define the true extent of benefits from the administration of adrenaline in anaphylaxis, such trials are unlikely to be performed in individuals with anaphylaxis. Indeed, they might be unethical because prompt treatment with adrenaline is deemed to be critically important for survival in anaphylaxis. Also, such studies would be difficult to conduct because anaphylactic episodes usually occur without warning, often in a non-medical setting, and differ in severity both among individuals and from one episode to another in the same individual. Consequently, obtaining baseline measurements and frequent timed measurements might be difficult, or impossible, to obtain. In the absence of appropriate trials, we recommend, albeit on the basis of less than optimal evidence, that adrenaline administration by intramuscular (i.m.) injection should still be regarded as first-line treatment for the management of anaphylaxis.

Concurrent inhibition of kit- and FcepsilonRI-mediated signaling: coordinated suppression of mast cell activation

Although primarily required for the growth, differentiation, and survival of mast cells, Kit ligand (stem cell factor) is also required for optimal antigen-mediated mast cell activation. Therefore, concurrent inhibition of Kit- and FcepsilonRI-mediated signaling would be an attractive approach for targeting mast cell-driven allergic reactions. To explore this concept, we examined the effects of hypothemycin, a molecule that we identified as having such properties, in human and mouse mast cells. Hypothemycin blocked Kit activation and Kit-mediated mast cell adhesion in a similar manner to the well characterized Kit inhibitor imatinib mesylate (imatinib). In contrast to imatinib, however, hypothemycin also effectively inhibited FcepsilonRI-mediated degranulation and cytokine production in addition to the potentiation of these responses via Kit. The effect of hypothemycin on Kit-mediated responses could be explained by its inhibition of Kit kinase activity, whereas the inhibitory effects on FcepsilonRI-dependent signaling were at the level of Btk activation. Because hypothemycin also significantly reduced the mouse passive cutaneous anaphylaxis response in vivo, these data provide proof of principle for a coordinated approach for the suppression of mast cell activation and provide a rationale for the development of compounds with a similar therapeutic profile.

The psychosocial impact of anaphylaxis on young people and their parents

BACKGROUND

Anaphylaxis is a potentially life-threatening disorder that can affect people of all ages. Young people are at a disproportionately increased risk of anaphylaxis deaths for reasons that include a failure to institute appropriate long-term management regimens. A pre-requisite for effective supported self-management of young people with anaphylaxis is a better understanding of the factors that contribute to risk-taking behaviour.

OBJECTIVE

To explore the psychosocial impact of living with anaphylaxis on adolescents and their parents; their management of the condition; and perceptions of health care provision.

METHODS

In-depth interviews were conducted with 15 participants, these comprising of seven adolescents aged between 13 and 16 years with a history of clinician-diagnosed anaphylaxis and eight of their parents, in this Scottish community-based exploratory qualitative study.

RESULTS

Adolescents in this study typically perceived anaphylaxis as 'no big deal', describing a relatively low impact on their day-to-day life when compared with their parents. This could largely be explained by the fact that most adolescents could not remember an anaphylactic reaction. Key obstacles to effective long-term self-management included inadequate knowledge to support detailed situation-specific risk assessment, this being compounded by a lack of confidence to make further enquiries about the ingredients of meals when with peers. Parents reported anxiety about 'handing over' the main responsibility for avoidance and emergency management to their children. Medical support for these families was very limited, with primary care teams in some cases actively hindering effective self-management.

CONCLUSION

Having a child with anaphylaxis can have a significant long-term psychological impact on parents and this anxiety may in some cases be transferred from parents onto their children. Parents and adolescents may benefit from tailored information to support the transition from parental- to self-management by adolescents. Access to appropriate national health service primary and specialist care was in some cases currently inadequate to support effective long-term management. Further, more in-depth research in a more heterogeneous group of adolescents is needed.

Food-dependent exercise-induced anaphylaxis in childhood

The clinical syndrome of food-dependent exercise-induced anaphylaxis (FDEIA) is typified by the onset of anaphylaxis during (or soon after) exercise which was preceded by the ingestion of the causal food allergen/s. In FDEIA, both the food allergen/s and exercise are independently tolerated. FDEIA is an uncommon allergic condition in childhood, but nonetheless is an important differential diagnosis to be considered when faced by a child who has experienced exercise-associated anaphylaxis. The diagnosis of FDEIA is heavily dependent on the clinical history. Allergy tests may need to be performed to a broad panel of food and food additives. Modified exercise challenges (performed with and without prior ingestion of food) are frequently required as allergy test results frequently return low-positive results. A diagnosis of FDEIA facilitates the safe independent return to exercise and reintroduction of foods for patients who otherwise may unnecessarily avoid exercise and/or restrict their diet. The natural history of FDEIA is unknown; however, a safe return is usually achieved when the ingestion of the causal food allergen/s and exercise are separated.

H1-antihistamines for the treatment of anaphylaxis: Cochrane systematic review

BACKGROUND

Anaphylaxis is an acute systemic allergic reaction, which can be life-threatening. H(1)-antihistamines are commonly used as an adjuvant therapy in the treatment of anaphylaxis. We sought to assess the benefits and harm of H(1)-antihistamines in the treatment of anaphylaxis.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library); MEDLINE (1966 to June 2006); EMBASE (1966 to June 2006); CINAHL (1982 to June 2006) and ISI Web of Science (1945 to July 2006). We also contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material. Randomized and quasi-randomized-controlled trials comparing H(1)-antihistamines with placebo or no intervention were eligible for inclusion. Two authors independently assessed articles for inclusion.

RESULTS

We found no studies that satisfied the inclusion criteria.

CONCLUSIONS

Based on this review, we are unable to make any recommendations for clinical practice. Randomized-controlled trials are needed, although these are likely to prove challenging to design and execute.

The Pathophysiology of Shock in Anaphylaxis

The balance of evidence from human observations and animal studies suggests that the main pathophysiologic features of anaphylactic shock are a profound reduction in venous tone and fluid extravasation causing reduced venous return (mixed hypovolemic-distributive shock) and depressed myocardial function. Aggressive fluid resuscitation is required to ameliorate hypovolemic-distributive shock, and an intravenous infusion of epinephrine will increase vascular tone, myocardial contractility, and cardiac output in most cases. Where these measures fail, pathophysiologic considerations and anecdotal evidence support the consideration of selective vasoconstrictors as the next step in treatment.

H1-antihistamines for the treatment of anaphylaxis with and without shock

BACKGROUND

Anaphylaxis is an acute systemic allergic reaction, which can be life-threatening. H1-antihistamines are commonly used as an adjuvant therapy in the treatment of anaphylaxis.

OBJECTIVES

To assess the benefits and harm of H1-antihistamines in the treatment of anaphylaxis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library), MEDLINE (1966 to June 2006);EMBASE (1966 to June 2006); CINAHL (1982 to June 2006) and ISI Web of Science (1945 to July 2006). We also contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing H1-antihistamines with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed articles for inclusion.

MAIN RESULTS

We found no studies that satisfied the inclusion criteria.

AUTHORS' CONCLUSIONS

Based on this review, we are unable to make any recommendations for clinical practice. Randomized controlled trials are needed, although these are likely to prove challenging to design and execute.