Summary
Definition
History and exam
Key diagnostic factors
- acute onset
- urticaria
- angioedema
- flushing
- dyspnea
- wheezing
- rhinitis
Other diagnostic factors
- allergen ingestion
- insect stings or bites
- pruritus
- inspiratory stridor and hoarse voice
- bilateral conjunctivitis
- nausea and vomiting
- abdominal cramping or pain
- agitation/anxiety
- confusion/disorientation
- tachycardia
- dizziness
- syncope
- sense of impending doom (angor animi)
- recent exercise
- hot or cold exposure
- hypotension
- bradycardia
- cardiac arrest
- diarrhea
- visual disturbances
- tremor
- seizures
Risk factors
- adult age: food-, insect venom-, and medication-related
- <30 years old: food-associated, exercise-induced
- female sex
- atopy/asthma
- history of anaphylaxis
- exposure to a common sensitizer (e.g., latex)
Diagnostic tests
1st tests to order
- serum tryptase level
Tests to consider
- in vitro IgE testing
- skin test
- challenge test
Emerging tests
- basophil activation test
Treatment algorithm
all patients: acute onset
patients with identified allergen
Contributors
Expert advisers
Nathan A. Blaseg, MD
Resident Physician
Pediatrics
University of Utah
Salt Lake City
UT
Disclosures
NAB declares that he has no competing interests.
Doerthe A. Andreae, MD
Associate Professor
Allergy/Immunology
Department of Dermatology
University of Utah
Salt Lake City
UT
Disclosures
DAA is author of an UpToDate article on food allergy, for which she receives royalties. DAA is an author of a number of references cited in this topic.
Acknowledgements
Dr Nathan A. Blaseg and Dr Doerthe A. Andreae would like to gratefully acknowledge Dr Michael Henning Andreae and Dr Andrea Vereda, previous contributors to this topic.
Disclosures
AV declares that she is currently employed by Aimmune Therapeutics. AV wrote the main content of this topic before taking up this appointment. MHA is an author of a reference cited in this topic.
Peer reviewers
Frank J. Domino, MD
Associate Professor
Family Medicine and Community Health
University of Massachusetts Medical School
Worcester
MA
Disclosures
FJD declares that he has no competing interests.
Wayne Shreffler, MD, PhD
Assistant Professor of Pediatrics
Mount Sinai School of Medicine
New York
NY
Disclosures
WS declares that he has no competing interests.
Lawrence Youlten, FRCP (Edin), PhD
Visiting Consultant in Allergy
Addenbrooke’s Hospital NHS Trust
Cambridge
UK
Disclosures
LY declares that he has no competing interests.
Grant Hayman, MBChB, MRCP, DTM and H, MSc, FRCPath
Consultant Immunologist
Department of Immunology
Epsom & St Helier University Hospitals NHS Trust
Carshalton
Surrey
UK
Disclosures
GH declares that he has no competing interests.
References
Key articles
Shaker MS, Wallace DV, Golden DBK, et al. Anaphylaxis - a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis. J Allergy Clin Immunol. 2020 Apr;145(4):1082-123.Full text Abstract
Cardona V, Ansotegui IJ, Ebisawa M, et al. World Allergy Organization anaphylaxis guidance 2020. World Allergy Organ J. 2020 Oct 30;13(10):100472.Full text Abstract
Golden DBK, Wang J, Waserman S, et al. Anaphylaxis: a 2023 practice parameter update. Ann Allergy Asthma Immunol. 2024 Feb;132(2):124-76.Full text Abstract
Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: adult basic and advanced life support: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020 Oct 20;142(16 suppl 2):S366-468.Full text Abstract
Reference articles
A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
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