EAACI guidelines: Anaphylaxis (2021 update)

Abstract

Antonella Muraro, Margitta Worm and Graham Roberts equally contributed as guideline chairs.This paper sets out the updated European Academy of Allergy and Clinical Immunology's (EAACI) guideline regarding the diagnosis, acute management, and prevention of anaphylaxis. Anaphylaxis is a clinical emergency and all healthcare professionals need to be familiar with its recognition and management. Anaphylaxis is a lifethreatening reaction characterized by acute onset of symptoms involving different organ systems and requiring immediate medical intervention. 1 Although the fatality rate due to anaphylaxis remains low, 2 the frequency of hospitalization from food and drug-induced anaphylaxis has been increasing in recent years. 3 The symptoms of anaphylaxis are highly variable. 4,5 Data from patients experiencing anaphylaxis revealed that skin and mucosal symptoms occur most frequently (>90% of cases) followed by symptoms involving the respiratory and cardiovascular systems (>50%). Food, drug, and Hymenoptera venom are the most common elicitors of anaphylactic reactions. 5,6 The prevalence of the various causes of anaphylaxis are age-dependent and vary in different geographical regions. In Europe, typical causes of food-induced anaphylaxis in children are peanut, hazelnut, milk, and egg and in adults, wheat, celery, and shellfish; fruits such as peach are also typical causes of food-induced anaphylaxis in adults in some European countries such as Spain and Italy. 7,8 Venom-induced anaphylaxis is typically caused by wasp and bee venom. 9 Drug-induced anaphylaxis is typically caused by antibiotics and non-steroidal anti-inflammatory drugs. 10,11 Among antibiotics, beta-lactam antibiotics are the leading eliciting allergens. 12 At times, there is an occupational cause. 13 Co-factors may be aggravating factors in anaphylaxis, examples are exercise, stress, infection, non-steroidal anti-inflammatory drugs, and alcohol. [14][15][16] In some cases, the cause is not obvious (idiopathic anaphylaxis) and investigations for rarer allergens or differential diagnoses should be considered. [17][18][19] This guideline, updated from 2014, 20 provides evidence-based guidance to help manage anaphylaxis. The primary audience is clinical allergists (specialists and subspecialists), primary care, paediatricians, emergency physicians, anaesthetists and intensivists, nurses, dieticians, and other healthcare professionals. The guideline was

CoronaVac COVID-19 Vaccine-Induced Anaphylaxis: Clinical Characteristics and Revaccination Outcomes

“…We diagnosed anaphylaxis based on clinical criteria and measured paired serum tryptase to confirm the diagnosis after a reaction while the demonstration of positive skin tests confirmed the trigger and is considered proof of IgE sensitization. 10 Many mechanisms of immediate vaccine hypersensitivity have been proposed, including IgEmediated mast cell activation, non-IgE-mediated mast cell activation, complement activation, and direct mast cell activation (eg, MRGPRX2). [11][12][13] All patients in our study had negative tryptase results.…”

Should steroids be used for anaphylaxis after the COVID-19 vaccine?

“…Although steroids are often used for treating anaphylaxis, there is no consensus among published guidelines regarding the use of glucocorticoids for the treatment of acute anaphylaxis. [17][18][19][20][21] Recent retrospective multicenter studies conducted at emergency departments have reported that glucocorticoids are more commonly administered for treating anaphylaxis than adrenaline, which is the traditional treatment for anaphylaxis. 22 One reason for this is that anaphylaxis is a biphasic reaction, which means that symptoms may recur after the initial anaphylaxis response resolves despite there being no further exposure to the antigen.…”

Pharmacokinetics of adrenaline autoinjectors

“…In community settings, adrenaline can be provided for emergency use as an adrenaline autoinjector (AAI) device, 7,8 although these are not available in many countries 13 . Carrying an AAI enables IM adrenaline to be rapidly administered by the patient or a lay person.…”

“…[3][4][5][6] The mainstay of longer-term management is avoidance of the trigger. 7,8 This can be challenging, particularly for food allergy, with the issues around allergen labelling 9 which impact adversely on quality of life. 10 The evidence base for the acute management of anaphylaxis is weak, but there is a global consensus that intramuscular (IM) adrenaline is the treatment of choice.…”

“…10 The evidence base for the acute management of anaphylaxis is weak, but there is a global consensus that intramuscular (IM) adrenaline is the treatment of choice. 7,8,11,12 In community settings, adrenaline can be provided for emergency use as an adrenaline autoinjector (AAI) device, 7,8 although these are not available in many countries. 13 Carrying an AAI enables IM adrenaline to be rapidly administered by the patient or a lay person.…”