Subscribe for unlimited access to DynaMed content, CME/CE & MOC credit, and email alerts on content you follow.

Already subscribed? Sign in now

Learn more about CME

Anaphylaxis

MoreVert
AddCircleOutlineFollow
ShareShare
AddCircleOutlineFollow
Follow
ShareShare
Share

General Information

Description

  • acute life-threatening allergic reaction that is rapid in onset, may rapidly progress to cardiovascular and respiratory arrest, and generally treated with epinephrine immediately1
  • clinical presentation, severity, and mechanism of reaction varies1

Definitions

  • clinical definition of anaphylaxis considered any 1 of 3 clinical scenarios
    • acute onset of a reaction (minutes to hours) with involvement of skin, mucosal tissue, or both (such as generalized hives, pruritus, flushing, or swelling of lips, tongue, or uvula) and at least 1 of
      • respiratory compromise (such as dyspnea, stridor, wheezing, or hypoxemia)
      • reduced blood pressure
      • symptoms of end-organ dysfunction (such as hypotonia, syncope, or incontinence)
    • 2 or more of the following reactions occurring rapidly (minutes to hours) after exposure to likely allergen
      • involvement of skin or mucosal tissue
      • respiratory compromise
      • reduced blood pressure or symptoms of end-organ dysfunction
      • persistent gastrointestinal symptoms (such as vomiting, crampy abdominal pain)
    • reduced blood pressure after exposure to known allergen; low systolic blood pressure (defined by age) or > 30% decrease in systolic blood pressure minutes to several hours after exposure to known allergen
      • in adults - low systolic blood pressure if < 90 mm Hg
      • at age 11-17 years - low systolic blood pressure if < 90 mm Hg
      • at age 1-10 years - low systolic blood pressure if < (70 mm Hg + [2 × age in years])
      • at age 1 month to 1 year - low systolic blood pressure if < 70 mm Hg
      • term neonates (0-28 days) - low systolic blood pressure if < 60 mm Hg
    • Reference - 16461139J Allergy Clin Immunol 2006 Feb;117(2):391OpenInNew
  • some patients may not fall under clinical definition of anaphylaxis (such as those with single system manifestation after exposure to likely allergen)1
  • anaphylactoid reaction - older terminology used to describe clinical anaphylaxis due to non-immunoglobulin E (IgE)-mediated reactions1

References

General references used

  1. Lieberman P, Nicklas RA, Randolph C, et al. American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology (AAAAI/ACAAI) Joint Task Force: Anaphylaxis - a practice parameter update 2015. Ann Allergy Asthma Immunol. 2015 Nov;115(5):341-84OpenInNewPDFPictureAsPdf
  2. Simons FE. Anaphylaxis. J Allergy Clin Immunol. 2010 Feb;125(2 Suppl 2):S161-81OpenInNew, correction can be found in J Allergy Clin Immunol 2010 Oct;126(4):885
  3. National Institute of Health and Care Excellence. Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. NICE 2011 Dec:CG134OpenInNewPDFPictureAsPdf, executive summary can be found in BMJ 2011 Dec 14;343:d7595OpenInNew
  4. Campbell RL, Li JT, Nicklas RA, Sadosty AT, Members of the Joint Task Force, Practice Parameter Workgroup. Emergency department diagnosis and treatment of anaphylaxis: a practice parameter. Ann Allergy Asthma Immunol. 2014 Dec;113(6):599-608OpenInNewPDFPictureAsPdf

Recommendation grading systems used

  • American Academy of Allergy, Asthma & Immunology/American College of Allergy, Asthma & Immunology/Joint Council of Allergy, Asthma & Immunology (AAAAI/ACAAI/JCAAI) grades of recommendation
    • recommendation rating scale
      • Strong recommendation - should be followed unless a clear and compelling rationale for an alternative approach is present
      • Moderate recommendation - should generally be followed, but remain alert to new information and sensitive to patient preferences
      • Weak recommendation - be flexible in decision-making process and set bounds on alternatives; patient preference should have substantial role
      • No recommendation - little restraint is called for in decision making, however remain alert to newly published evidence that clarifies benefit vs. harm; patient preference should have substantial role
    • strength of recommendation
      • Grade A - based on Category I evidence
      • Grade B - based on Category II evidence or extrapolated from Category I evidence
      • Grade C - based on Category III evidence or extrapolated from Category I-II evidence
      • Grade D - based on Category IV evidence or extrapolated from Category I-III evidence
      • Grade LB - laboratory based
      • Grade NR - not rated
    • categories of evidence
      • Category Ia - evidence from meta-analysis of randomized controlled trials
      • Category Ib - evidence from ≥ 1 randomized controlled trial
      • Category IIa - evidence from ≥ 1 controlled study without randomization
      • Category IIb - evidence from ≥ 1 other type of quasi-experimental study
      • Category III - evidence from nonexperimental descriptive studies (for example, comparative studies)
      • Category IV - evidence from expert committee reports, clinical experience or opinions of respected authorities, or both
    • Reference - AAAAI/ACAAI/JCAAI 2014 updated practice parameter on food allergy (25174862J Allergy Clin Immunol 2014 Nov;134(5):1016OpenInNew)
  • American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology (AAAAI/ACAAI) Joint Task Force on Practice Parameters 2015 grading of recommendations
    • strength of recommendation
      • Strong recommendation - benefits of recommended approach clearly exceed harms (or vice versa in case of strong negative recommendation) and quality of supporting evidence is excellent (grade A or B) or in some circumstances lesser evidence when high-quality evidence is impossible to obtain
      • Recommendation - benefits of recommended approach exceed harms (or harms clearly exceed benefits in case of negative recommendation) but quality of supporting evidence is not as strong (grade B or C) or in some circumstances lesser evidence when high-quality evidence is impossible to obtain
      • Weak recommendation - quality of evidence that exists is suspect (grade D) or well-done studies (grade A, B, or C) show little clear advantage to one approach vs. another
      • No recommendation - lack of pertinent evidence (grade D) and unclear balance between benefits and harms
    • strength of evidence
      • Grade A - directly based on category I evidence that is well-designed
      • Grade B - directly based on category II evidence or on category I evidence that is not well-designed
      • Grade C - directly based on category III evidence or category II evidence that is not well-designed
      • Grade D - directly based on category IV evidence or category III evidence that is not well-designed
      • Grade LB - laboratory-based
      • Grade NR - not rated
    • categories of evidence
      • Ia - evidence from meta-analysis of randomized controlled trials
      • Ib - evidence from ≥ 1 well-designed randomized controlled trial
      • Ic - evidence from ≥ 1 randomized controlled trial that was not very well-designed
      • IIa - evidence from ≥ 1 controlled study without randomization
      • IIb - evidence from ≥ 1 other type of quasi-experimental study
      • IIc - evidence from 1 of the above that was not very well-designed
      • IIIa - evidence from well-designed nonexperimental descriptive studies (such as comparative studies)
      • IIIb - evidence from nonexperimental descriptive studies (such as comparative studies) that were not very well-designed
      • IVa - evidence from expert committee reports and/or opinions or clinical experience of respected authorities
    • Reference - AAAAI/ACAAI 2015 updated practice parameter on anaphylaxis ( 26505932Ann Allergy Asthma Immunol 2015 Nov;115(5):341OpenInNewPDFPictureAsPdf)
  • American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology (AAAAI/ACAAI) Joint Task Force on Practice Parameters 2014 grading of recommendations
    • strength of recommendation
      • Strong recommendation - benefits of recommended approach clearly exceed harms (or vice versa in case of strong negative recommendation) and quality of supporting evidence is excellent (grade A or B) or in some circumstances lesser evidence when high-quality evidence is impossible to obtain
      • Moderate recommendation - benefits of recommended approach exceed harms (or harms clearly exceed benefits in case of negative recommendation) but quality of supporting evidence is not as strong (grade B or C) or in some circumstances lesser evidence when high-quality evidence is impossible to obtain
      • Weak recommendation - quality of evidence that exists is suspect (grade D) or well-done studies (grade A, B, or C) show little clear advantage to one approach vs. another
      • No recommendation - lack of pertinent evidence (grade D) and unclear balance between benefits and harms
    • strength of evidence
      • Grade A - directly based on category I evidence
      • Grade B - directly based on category II evidence or extrapolated from category I evidence
      • Grade C - directly based on category III evidence or extrapolated from category I or II evidence
      • Grade D - directly based on category IV evidence or extrapolated from I, II, or III evidence
      • Grade LB - laboratory-based
      • Grade NR - not rated
    • categories of evidence
      • Ia - evidence from meta-analysis of randomized controlled trials
      • Ib - evidence from ≥ 1 randomized controlled trial
      • IIa - evidence from ≥ 1 controlled study without randomization
      • IIb - evidence from ≥ 1 other type of quasi-experimental study
      • III - evidence from nonexperimental descriptive studies (such as comparative studies)
      • IV - evidence from expert committee reports and/or opinions or clinical experience of respected authorities
    • Reference - AAAAI/ACAAI practice parameter on emergency department diagnosis and treatment of anaphylaxis (25466802Ann Allergy Asthma Immunol 2014 Dec;113(6):599OpenInNewPDFPictureAsPdf)
  • American Academy of Allergy, Asthma, and Immunology/American College of Allergy, Asthma, and Immunology (AAAAI/ACAAI) Joint Task Force on Practice Parameters 2010 grading of recommendations
    • strength of recommendation
      • Grade A - directly based on category I evidence
      • Grade B - directly based on category II evidence or extrapolated from category I evidence
      • Grade C - directly based on category III evidence or extrapolated from category I or II evidence
      • Grade D - directly based on category IV evidence or extrapolated from I, II, or III evidence
      • Grade LB - laboratory-based
    • categories of evidence
      • Ia - evidence from meta-analysis of randomized controlled trials
      • Ib - evidence from ≥ 1 randomized controlled trial
      • IIa - evidence from ≥ 1 controlled study without randomization
      • IIb - evidence from ≥ 1 other type of quasi-experimental study
      • III - evidence from nonexperimental descriptive studies (such as comparative studies)
      • IV - evidence from expert committee reports and/or opinions or clinical experience of respected authorities
    • Reference - AAAAI/ACAAI 2010 practice parameter on diagnosis and management of anaphylaxis (20692689J Allergy Clin Immunol 2010 Sep;126(3):477OpenInNew)
  • American College of Cardiology Foundation/American Heart Association (ACCF/AHA) grading system for recommendations
    • classifications of recommendations
      • Class I - procedure or treatment should be performed or administered
      • Class IIa - reasonable to perform procedure or administer treatment, but additional studies with focused objectives needed
      • Class IIb - procedure or treatment may be considered; additional studies with broad objectives needed, additional registry data would be useful
      • Class III - procedure or treatment should not be performed or administered because it is not helpful or may be harmful
        • Class III ratings may be subclassified as Class III No Benefit or Class III Harm
    • levels of evidence
      • Level A - data derived from multiple randomized clinical trials or meta-analyses
      • Level B - data derived from single randomized trial or nonrandomized studies
      • Level C - only expert opinion, case studies, or standard of care

Synthesized Recommendation Grading System for DynaMed

  • DynaMed systematically monitors clinical evidence to continuously provide a synthesis of the most valid relevant evidence to support clinical decision-making (see 7-Step Evidence-Based MethodologyOpenInNew).
  • Guideline recommendations summarized in the body of a DynaMed topic are provided with the recommendation grading system used in the original guideline(s), and allow DynaMed users to quickly see where guidelines agree and where guidelines differ from each other and from the current evidence.
  • In DynaMed (DM), we synthesize the current evidence, current guidelines from leading authorities, and clinical expertise to provide recommendations to support clinical decision-making in the Overview & Recommendations section.
  • We use the Grading of Recommendations Assessment, Development and Evaluation (GRADE)OpenInNew to classify synthesized recommendations as Strong or Weak.
    • Strong recommendations are used when, based on the available evidence, clinicians (without conflicts of interest) consistently have a high degree of confidence that the desirable consequences (health benefits, decreased costs and burdens) outweigh the undesirable consequences (harms, costs, burdens).
    • Weak recommendations are used when, based on the available evidence, clinicians believe that desirable and undesirable consequences are finely balanced, or appreciable uncertainty exists about the magnitude of expected consequences (benefits and harms). Weak recommendations are used when clinicians disagree in judgments of relative benefit and harm, or have limited confidence in their judgments. Weak recommendations are also used when the range of patient values and preferences suggests that informed patients are likely to make different choices.
  • DynaMed (DM) synthesized recommendations (in the Overview & Recommendations section) are determined with a systematic methodology:
    • Recommendations are initially drafted by clinical editors (including ≥ 1 with methodological expertise and ≥ 1 with content domain expertise) aware of the best current evidence for benefits and harms, and the recommendations from guidelines.
    • Recommendations are phrased to match the strength of recommendation. Strong recommendations use "should do" phrasing, or phrasing implying an expectation to perform the recommended action for most patients. Weak recommendations use "consider" or "suggested" phrasing.
    • Recommendations are explicitly labeled as Strong recommendations or Weak recommendations when a qualified group has explicitly deliberated on making such a recommendation. Group deliberation may occur during guideline development. When group deliberation occurs through DynaMed-initiated groups:
      • Clinical questions will be formulated using the PICO (Population, Intervention, Comparison, Outcome) framework for all outcomes of interest specific to the recommendation to be developed.
      • Systematic searches will be conducted for any clinical questions where systematic searches were not already completed through DynaMed content development.
      • Evidence will be summarized for recommendation panel review including for each outcome, the relative importance of the outcome, the estimated effects comparing intervention and comparison, the sample size, and the overall quality rating for the body of evidence.
      • Recommendation panel members will be selected to include at least 3 members that together have sufficient clinical expertise for the subject(s) pertinent to the recommendation, methodological expertise for the evidence being considered, and experience with guideline development.
      • All recommendation panel members must disclose any potential conflicts of interest (professional, intellectual, and financial), and will not be included for the specific panel if a significant conflict exists for the recommendation in question.
      • Panel members will make Strong recommendations if and only if there is consistent agreement in a high confidence in the likelihood that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. Panel members will make Weak recommendations if there is limited confidence (or inconsistent assessment or dissenting opinions) that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. No recommendation will be made if there is insufficient confidence to make a recommendation.
      • All steps in this process (including evidence summaries which were shared with the panel, and identification of panel members) will be transparent and accessible in support of the recommendation.
    • Recommendations are verified by ≥ 1 editor with methodological expertise, not involved in recommendation drafting or development, with explicit confirmation that Strong recommendations are adequately supported.
    • Recommendations are published only after consensus is established with agreement in phrasing and strength of recommendation by all editors.
    • If consensus cannot be reached then the recommendation can be published with a notation of "dissenting commentary" and the dissenting commentary is included in the topic details.
    • If recommendations are questioned during peer review or post publication by a qualified individual, or reevaluation is warranted based on new information detected through systematic literature surveillance, the recommendation is subject to additional internal review.

DynaMed Editorial Process

Special acknowledgements

  • DynaMed topics are written and edited through the collaborative efforts of the above individuals. Deputy Editors, Section Editors, and Topic Editors are active in clinical or academic medical practice. Recommendations Editors are actively involved in development and/or evaluation of guidelines.
  • Editorial Team role definitions
    Topic Editors define the scope and focus of each topic by formulating a set of clinical questions and suggesting important guidelines, clinical trials, and other data to be addressed within each topic. Topic Editors also serve as consultants for the internal DynaMed Editorial Team during the writing and editing process, and review the final topic drafts prior to publication.
    Section Editors have similar responsibilities to Topic Editors but have a broader role that includes the review of multiple topics, oversight of Topic Editors, and systematic surveillance of the medical literature.
    Recommendations Editors provide explicit review of DynaMed Overview and Recommendations sections to ensure that all recommendations are sound, supported, and evidence-based. This process is described in "Synthesized Recommendation Grading."
    Deputy Editors are employees of DynaMed and oversee DynaMed internal publishing groups. Each is responsible for all content published within that group, including supervising topic development at all stages of the writing and editing process, final review of all topics prior to publication, and direction of an internal team.

How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T113858, Anaphylaxis; [updated 2018 Nov 30, cited place cited date here]. Available from https://www.dynamed.com/topics/dmp~AN~T113858. Registration and login required.

top

CheckCircle
Subscribe for unlimited access to DynaMed content.
Already subscribed? Sign in