Anaphylaxis

Publication Date: December 17, 2023
Last Updated: January 12, 2024

Diagnosis

We recommend obtaining a bST in patients presenting with a history of recurrent, idiopathic, or severe anaphylaxis, particularly those presenting with hypotension. (S, M )
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We suggest drawing an acute-phase tryptase level as early as possible during a suspected anaphylactic event (ideally within 2 hours after onset of symptoms). We suggest drawing a second tryptase measurement at a later time as a baseline for comparison to determine whether there was a significant acute elevation. (C, M )
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We suggest clinicians consider evaluation for HαT in patients with elevated bST level (8 ng/mL or greater). (C, L )
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We suggest clinicians consider evaluation for mastocytosis, including a bone marrow biopsy, for adult patients with severe insect sting anaphylaxis or recurrent IA, particularly those with a predictive REMA score. (C, M )
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We suggest that clinicians consider alpha-gal allergy as a possible cause of recurrent IA in a patient with history of possible tick bite; when appropriate, check an alpha-gal IgE and advise a trial elimination of mammalian meat if alpha-gal IgE sensitization is detected. (C, M )
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We suggest that meeting diagnostic criteria for anaphylaxis is not required before the use of epinephrine. (C, VL )
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We suggest that neither the clinical decision to administer epinephrine nor the clinical response to epinephrine be used as a surrogate marker to establish a diagnosis of anaphylaxis. (C, VL )
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Anaphylaxis in Infants and Toddlers

We suggest clinicians use current NIAID/FAAN or WAO anaphylaxis criteria to assist in the diagnosis of anaphylaxis in infants/toddlers, because there are no criteria specific to this age group. (C, L )
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We suggest clinicians be aware that, in infants and toddlers, patient age does not correlate with reaction severity. (C, VL )
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We suggest clinicians be aware that anaphylaxis is unlikely to be the initial reaction to a food or medication on first exposure in infants. (C, L )
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We suggest clinicians be aware that parents of infants and toddlers may report age-specific symptoms that are less often reported by older children and adults. (C, VL )
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We suggest clinicians prescribe either the 0.1 mg or the 0.15 mg EAI dose for infants/toddlers weighing less than 15 kg. (C, L )
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Anaphylaxis in Community Settings

We recommend clinicians counsel patients at high risk of anaphylaxis to always carry self-injectable epinephrine and teach patients proper indications and use. (S, VL )
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We recommend clinicians educate patients on avoidance of potential exposure to their allergen(s). (S, VL )
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We recommend clinicians educate patients that the main route of food-induced anaphylaxis is by ingestion and not contact or inhalation. (S, M )
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We suggest childcare centers and schools implement staff training for allergy and anaphylaxis management. (C, VL )
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We suggest that childcare centers and schools not implement site-wide food-specific prohibition because current research does not support consistent benefits. Special circumstances: It might be appropriate to implement allergen-restricted zones (eg, milk-free table) when there are children who lack the capacity to self-manage. (C, VL )
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We suggest that childcare centers and schools stock undesignated EAIs that can be used to treat any individual on school grounds who experiences anaphylaxis. (C, VL )
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We suggest clinicians counsel patients that although US regulations require disclosure of major allergens on labels of prepackaged foods, they do not require restaurants to declare ingredients or provide allergy warnings for non-prepackaged foods. (C, VL )
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We suggest clinicians counsel patients on safe practices for dining outside of the home. (C, VL )
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We suggest that advising individuals at risk of anaphylaxis to wear or carry medical identification (eg, jewelry or wallet card) be considered optional. If it is worn or carried, the wording on medical alert jewelry or wallet cards should be verified for accuracy by a health care professional. (C, VL )
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We suggest that keeping stock EAI in community settings be encouraged, if feasible. (C, VL )
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Epinephrine Autoinjectors

We suggest clinicians routinely prescribe EAIs to patients at higher risk of anaphylaxis. When deciding whether to prescribe EAIs to lower risk patients, we suggest that clinicians engage in a shared decision-making process that considers the patients’ risk factors, values, and preferences. (C, VL )
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We suggest that in jurisdictions where single-packs of EAIs are available, clinicians consider a patient's risk factors for severe anaphylaxis, their values and preferences, and contextual factors when deciding whether to prescribe only 1 vs multiple EAIs. We suggest they routinely prescribe more than one EAI when patients have previously required multiple doses of epinephrine to treat an episode of anaphylaxis and/or have a history of biphasic reactions. (C, VL )
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We suggest that clinicians counsel patients and caregivers to give epinephrine at the first sign of suspected anaphylaxis. We suggest that, in general, clinicians counsel patients or caregivers not to give epinephrine preemptively to an asymptomatic patient. (C, VL )
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We suggest that clinicians counsel patients that immediate activation of EMS may not be required if the patient experiences prompt, complete, and durable response to treatment with epinephrine, provided that additional epinephrine and medical care are readily available, if needed. We suggest that clinicians counsel patients to always activate EMS after epinephrine use if anaphylaxis is severe, fails to resolve promptly, fails to resolve completely or nearly completely, or returns or worsens after a first dose of epinephrine. (C, VL )
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Serious adverse reactions to intramuscular epinephrine are very rare and should not pose a barrier to the prescription or early administration of EAIs when indicated. To manage the risk of adverse events, we recommend that clinicians counsel patients and caregivers on the proper use of EAIs, the common adverse effects, and the need for immediate evaluation and treatment when signs or symptoms of serious adverse events develop. (S, L )
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We suggest that clinicians discuss the potential financial and psychosocial burdens of EAIs with patients while engaging in shared decision-making. (C, VL )
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When deciding which EAI to prescribe, we suggest that clinicians consider dosage, needle length, affordability, access, and patient treatment preferences. (C, VL )
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During visits with patients who have been prescribed EAIs, we recommend that clinicians routinely review the essentials of EAI carriage, storage, and use; encourage patients to regularly practice EAI administration with a trainer device; and discuss strategies to manage barriers to adherence that patients may have experienced. (S, L )
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Beta-Blocker and Angiotensin-Converting Enzyme Inhibitor Medications

We suggest that patients with a history of insect sting anaphylaxis who are not receiving VIT may continue BB or ACEI medications when the medical necessity of the daily medication outweighs the chance of increased severity of anaphylaxis to a sting. (C, L )
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We suggest that VIT may be prescribed for patients with a history of insect sting anaphylaxis who are treated with BB or ACEI medication, with shared decision-making regarding the benefits and potential harms of concurrent VIT treatment and medication, compared with withholding either the treatment or the medication. (C, L )
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We suggest that, in most cases, treatment with BB or ACEI medication need not be changed or discontinued in patients receiving maintenance VIT. (C, M )
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We suggest use of initial AIT may be considered in patients who are treated with BB or ACEI medication, with shared decision-making. It would be preferable to replace the BB or ACEI, if there is a safe and effective alternative. (C, L )
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We suggest that patients receiving maintenance dose AIT have a minimal increased risk of a severe anaphylactic reaction when on BB/ACEI medication and may consider continuing AIT and medications based on shared decision-making. (C, L )
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For planned procedures (eg, RCM, challenge/desensitization, and infusion), if the BB/ACEI medication cannot be safely interrupted, we suggest shared decision-making discussion of the medical necessity (benefit) of the procedure, the relative risk of anaphylaxis, the possibility of more severe reaction if the medication is continued, and the risk of stopping the medication. (C, VL )
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We suggest that all patients at significant risk for recurrent and unexpected anaphylaxis (eg, those with severe food allergy, mastocytosis or MCAS, or recurrent IA) be counseled about the risk of more severe anaphylaxis and consider avoiding, where possible, the use of nonselective BBs or ACEIs. (C, M )
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Mastocytosis and Anaphylaxis

We recommend clinicians order a bone marrow biopsy with staining for tryptase, CD25 immunohistochemistry and flow cytometry, and the KIT D816V mutation when there is strong suspicion for systemic mastocytosis. (S, M )
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We recommend clinicians not rely on serum tryptase levels alone for diagnostic assessment of the likelihood that a patient does or does not have a clonal mast cell disorder. (S, M )
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We recommend measurement of bST in: patients with severe insect sting anaphylaxis, particularly those who had hypotension and/or absence of urticaria; in all cases of recurrent unexplained anaphylaxis; and in patients with suspected mastocytosis. (S, M )
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We suggest clinicians consider evaluation for mastocytosis, including a bone marrow biopsy, for adult patients with severe insect sting anaphylaxis or recurrent IA, particularly those with a predictive REMA score. (C, M )
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We suggest VIT be continued indefinitely in patients with mastocytosis and insect sting anaphylaxis due to the increased risk of severe or fatal sting anaphylaxis if VIT is discontinued. (C, L )
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Perioperative Anaphylaxis

We suggest that immediate hypersensitivity skin testing (percutaneous and intradermal) and/or in vitro-specific IgE testing be performed, when available, to all potential pharmacologic and nonpharmacologic culprits used during the perioperative period. If testing is not possible, we suggest referral to another center or, if necessary, use of the most efficacious agents structurally dissimilar from the most likely culprit. (C, VL )
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We suggest that immediate hypersensitivity testing to suspected culprit (and alternative) agents be delayed after POA, unless repeat surgery cannot be postponed. If surgery with general anesthesia is needed sooner, then testing may be performed when needed. (C, VL )
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We suggest that challenges be performed, when feasible, to all potential culprit agents to which skin and/or in vitro testing is negative, before or in conjunction with use of these agents for a future surgical procedure. (C, VL )
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We suggest that repeat anesthesia may proceed in the context of shared decision-making and as directed by history and results of diagnostic evaluation. (C, L )
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We suggest that avoidance of culprit pharmacologic and nonpharmacologic agents associated with POA may be considered, regardless of test results if challenge is not feasible and if equally efficacious, structurally unrelated alternatives are available. (C, L )
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We offer no recommendation for or against the use of pretreatment before return to the operating room in patients with negative cutaneous (percutaneous and intradermal) and/or in vitro-specific IgE testing (and challenge when possible) result to all suspected POA culprit agents. (U, VL )
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Recommendation Grading

Abbreviations

  • ACEI: Angiotensin-converting Enzyme Inhibitor
  • AIT: Allergen Immunotherapy
  • BB:

    beta-blocker

  • EAI:

    epinephrine Autoinjector

  • EMS: Emergency Medical Services
  • HαT:

    hereditary α-tryptasemia

  • IA:

    idiopathic Anaphylaxis

  • MCAS: Mast Cell Activating Syndrome
  • NIAID: National Institute Of Allergy And Infectious Diseases
  • POA:

    perioperative Anaphylaxis

  • RCM: Radiocontrast Media
  • REMA:

    Red Espanola Mastocitosis

  • VIT:

    venom Immunotherapy

  • WAO:

    World Allergy Organization

  • bST: Baseline Serum Tryptase

Overview

Title

Anaphylaxis

Authoring Organizations

Publication Month/Year

December 17, 2023

Last Updated Month/Year

February 16, 2024

Supplemental Implementation Tools

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Document Objectives

Abstract: 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.

Inclusion Criteria

Male, Female, Adolescent, Adult, Child, Older adult

Health Care Settings

Ambulatory, Childcare center, Correctional facility, Emergency care, Home health, Hospital, Long term care, Medical transportation, Outpatient, School, Operating and recovery room

Intended Users

Athletics coaching, law enforcement, nurse, nurse practitioner, community pharmacist, physician, physician assistant

Scope

Treatment, Management, Prevention

Diseases/Conditions (MeSH)

D000707 - Anaphylaxis

Keywords

anaphylaxis, epinephrine

Source Citation

David B.K. Golden, Julie Wang, Susan Waserman, Cem Akin, Ronna L. Campbell, Anne K. Ellis, Matthew Greenhawt, David M. Lang, Dennis K. Ledford, Jay Lieberman, John Oppenheimer, Marcus S. Shaker, Dana V. Wallace, Elissa M. Abrams, Jonathan A. Bernstein, Derek K. Chu, Caroline C. Horner, Matthew A. Rank, David R. Stukus, Alyssa G. Burrows, Heather Cruickshank, David B.K. Golden, Julie Wang, Cem Akin, Ronna L. Campbell, Anne K. Ellis, Matthew Greenhawt, David M. Lang, Dennis K. Ledford, Jay Lieberman, John Oppenheimer, Marcus S. Shaker, Dana V. Wallace, Susan Waserman, Elissa M. Abrams, Jonathan A. Bernstein, Derek K. Chu, Anne K. Ellis, David B.K. Golden, Matthew Greenhawt, Caroline C. Horner, Dennis K. Ledford, Jay Lieberman, Matthew A. Rank, Marcus S. Shaker, David R. Stukus, Julie Wang, Anaphylaxis: A 2023 practice parameter update, Annals of Allergy, Asthma & Immunology, 2023, ISSN 1081-1206, https://doi.org/10.1016/j.anai.2023.09.015.

Supplemental Methodology Resources

Systematic Review Document, Data Supplement