Anaphylaxis: Recognition and Management


Am Fam Physician. 2020 Sep 15;102(6):355-362.

  Patient information: A handout on this topic is available at

Author disclosure: No relevant financial affiliations.

Anaphylaxis is a life-threatening systemic reaction, normally occurring within one to two hours of exposure to an allergen. The incidence of anaphylaxis in the United States is 2.1 per 1,000 person-years. Most anaphylactic reactions occur outside the hospital setting. Urticaria, difficulty breathing, and mucosal swelling are the most common symptoms of anaphylaxis. The most common triggers are medications, stinging insect venoms, and foods; however, unidentified triggers occur in up to one-fifth of cases. Coexisting asthma, mast cell disorders, older age, underlying cardiovascular disease, peanut and tree nut allergy, and drug-induced reactions are associated with severe or fatal anaphylactic reactions. Clinicians can obtain serum tryptase levels, reflecting mast cell degranulation, when the clinical diagnosis of anaphylaxis is not clear. Acute management of anaphylaxis involves removal of the trigger; early administration of intramuscular epinephrine; supportive care for the patient's airway, breathing, and circulation; and a period of observation for potential biphasic reactions. Only after epinephrine administration should adjunct medications be considered; these include histamine H1 and H2 antagonists, corticosteroids, beta2 agonists, and glucagon. Patients should be monitored for a biphasic reaction (i.e., recurrence of anaphylaxis without reexposure to the allergen) for four to 12 hours, depending on risk factors for severe anaphylaxis. Following an anaphylactic reaction, management should focus on developing an emergency action plan, referral to an allergist, and patient education on avoidance of triggers and appropriate use of an epinephrine auto-injector.

Anaphylaxis is a severe allergic reaction that occurs quickly and can be fatal. The incidence of anaphylaxis in the United States between 2004 and 2016 was 2.1 per 1,000 person-years, with one-fourth of anaphylactic reactions affecting children younger than 17 years.1  Most anaphylactic reactions occur outside the hospital setting (Table 1),2,3 and most individuals go to the hospital or emergency department for treatment.2,4 In the United States, the incidence of anaphylaxis peaks in children two to 12 years of age and in adults between 50 and 69 years of age.1 One out of 20 of all anaphylaxis cases may require hospitalization1,2; in the United States, hospitalizations for anaphylaxis have steadily increased over the past 10 years.5 The annual number of confirmed anaphylaxis-related deaths in the United States ranges from 186 to 225.5 The average fatality rate is 0.3% for most hospitalizations or emergency department presentations for anaphylaxis.5 Risk factors for severe or fatal anaphylaxis include coexisting asthma, mast cell disorders, age older than 50 years, underlying cardiovascular disease, peanut and tree nut allergy, and drug-induced reactions.610


One out of 20 of all anaphylaxis cases requires hospitalization; in the United States, hospitalizations for anaphylaxis have steadily increased over the past 10 years.

Gastrointestinal and respiratory symptoms of anaphylaxis are more likely to be overlooked in children. Only 55% of health care professionals recognize anaphylaxis without cutaneous involvement.

One-half of patients presenting to the emergency department who meet the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network diagnostic criteria for anaphylaxis receive treatment with epinephrine.

The Authors

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MATTHEW C. PFLIPSEN, MD, is a candidate in the Masters of Health Professions Education program and an assistant professor in the Department of Family Medicine at the Uniformed Services University of the Health Sciences, Bethesda, Md....

KARLA M. VEGA COLON, MD, FAAFP, is the officer in charge and medical director of the Madigan Army Medical Center Family Medicine Residency Program, Tacoma, Wash.; an assistant professor in the Department of Family Medicine at the Uniformed Services University of the Health Sciences; and a clinical instructor in the Department of Family Medicine at the University of Washington, Seattle.

Address correspondence to Matthew C. Pflipsen, MD, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814 (email: Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.


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1. Chaaban MR, Warren Z, Baillargeon JG, et al. Epidemiology and trends of anaphylaxis in the United States, 2004–2016. Int Forum Allergy Rhinol. 2019;9(6):607–614....

2. Wood RA, Camargo CA Jr, Lieberman P, et al. Anaphylaxis in America: the prevalence and characteristics of anaphylaxis in the United States. J Allergy Clin Immunol. 2014;133(2):461–467.

3. Rudders SA, Banerji A, Clark S, et al. Age-related differences in the clinical presentation of food-induced anaphylaxis. J Pediatr. 2011;158(2):326–328.

4. Lee S, Hess EP, Lohse C, et al. Trends, characteristics, and incidence of anaphylaxis in 2001–2010: a population-based study. J Allergy Clin Immunol. 2017;139(1):182–188.e2.

5. Ma L, Danoff TM, Borish L. Case fatality and population mortality associated with anaphylaxis in the United States. J Allergy Clin Immunol. 2014;133(4):1075–1083.

6. Jerschow E, Lin RY, Scaperotti MM, et al. Fatal anaphylaxis in the United States, 1999–2010: temporal patterns and demographic associations. J Allergy Clin Immunol. 2014;134(6):1318–1328.e7.

7. Kim SY, Kim MH, Cho YJ. Different clinical features of anaphylaxis according to cause and risk factors for severe reactions. Allergol Int. 2018;67(1):96–102.

8. Lieberman P, Nicklas RA, Randolph C, et al. Anaphylaxis—a practice parameter update 2015. Ann Allergy Asthma Immunol. 2015;115(5):341–384.

9. Motosue MS, Bellolio MF, Van Houten HK, et al. Risk factors for severe anaphylaxis in the United States. Ann Allergy Asthma Immunol. 2017;119(4):356–361.e2.

10. Muraro A, Roberts G, Worm M, et al.; EAACI Food Allergy and Anaphylaxis Guidelines Group. Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology. Allergy. 2014;69(8):1026–1045.

11. Simons FE, Ardusso LR, Bilò MB, et al.; World Allergy Organization. World Allergy Organization guidelines for the assessment and management of anaphylaxis. World Allergy Organ J. 2011;4(2):13–37.

12. Tang AW. A practical guide to anaphylaxis [published correction appears in Am Fam Physician. 2004;69(5):1049]. Am Fam Physician. 2003;68(7):1325–1332. Accessed August 28, 2019.

13. Australasian Society of Clinical Immunology and Allergy. Acute management of anaphylaxis. Accessed October 4, 2019.

14. Sampson HA, Muñoz-Furlong A, Campbell RL, et al. Second symposium on the definition and management of anaphylaxis: summary report—Second National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network symposium. J Allergy Clin Immunol. 2006;117(2):391–397.

15. Goetz VL, Kim K, Stang AS. Pediatric anaphylaxis in the emergency department: clinical presentation, quality of care, and reliability of consensus criteria. Pediatr Emerg Care. 2019;35(1):28–31.

16. Alvarez-Perea A, Tomás-Pérez M, Martínez-Lezcano P, et al. Anaphylaxis in adolescent/adult patients treated in the emergency department: differences between initial impressions and the definitive diagnosis. J Investig Allergol Clin Immunol. 2015;25(4):288–294.

17. Thomson H, Seith R, Craig S. Downstream consequences of diagnostic error in pediatric anaphylaxis. BMC Pediatr. 2018;18(1):40.

18. Goh SH, Soh JY, Loh W, et al. Cause and clinical presentation of anaphylaxis in Singapore: from infancy to old age. Int Arch Allergy Immunol. 2018;175(1–2):91–98.

19. Cohen N, Capua T, Pivko D, et al. Trends in the diagnosis and management of anaphylaxis in a tertiary care pediatric emergency department. Ann Allergy Asthma Immunol. 2018;121(3):348–352.

20. Rueter K, Ta B, Bear N, et al. Increased use of adrenaline in the management of childhood anaphylaxis over the last decade. J Allergy Clin Immunol Pract. 2018;6(5):1545–1552.

21. Campbell RL, Hagan JB, Li JT, et al. Anaphylaxis in emergency department patients 50 or 65 years or older. Ann Allergy Asthma Immunol. 2011;106(5):401–406.

22. Russell S, Monroe K, Losek JD. Anaphylaxis management in the pediatric emergency department: opportunities for improvement. Pediatr Emerg Care. 2010;26(2):71–76.

23. Jung WS, Kim SH, Lee H. Missed diagnosis of anaphylaxis in patients with pediatric urticaria in emergency department [published online October 2, 2018]. Pediatr Emerg Care. Accessed October 2, 2019.

24. Wang J, Young MC, Nowak-Węgrzyn A. International survey of knowledge of food-induced anaphylaxis. Pediatr Allergy Immunol. 2014;25(7):644–650.

25. Campbell RL, Li JT, Nicklas RA, et al.; Members of the Joint Task Force; Practice Parameter Workgroup. Emergency department diagnosis and treatment of anaphylaxis: a practice parameter. Ann Allergy Asthma Immunol. 2014;113(6):599–608.

26. Simons FE, Ebisawa M, Sanchez-Borges M, et al. 2015 update of the evidence base: World Allergy Organization anaphylaxis guidelines. World Allergy Organ J. 2015;8(1):32.

27. Jeong K, Lee SY, Ahn K, et al. A multicenter study on anaphylaxis caused by peanut, tree nuts, and seeds in children and adolescents. Allergy. 2017;72(3):507–510.

28. Turner PJ, Jerschow E, Umasunthar T, et al. Fatal anaphylaxis: mortality rate and risk factors. J Allergy Clin Immunol Pract. 2017;5(5):1169–1178.

29. Siracusa A, Folletti I, Gerth van Wijk R, et al. Occupational anaphylaxis—an EAACI task force consensus statement. Allergy. 2015;70(2):141–152.

30. Tang ML, Osborne N, Allen K. Epidemiology of anaphylaxis. Curr Opin Allergy Clin Immunol. 2009;9(4):351–356.

31. Umasunthar T, Leonardi-Bee J, Turner PJ, et al. Incidence of food anaphylaxis in people with food allergy: a systematic review and meta-analysis. Clin Exp Allergy. 2015;45(11):1621–1636.

32. Castilano A, Sternard B, Cummings ED, et al. Pitfalls in anaphylaxis diagnosis and management at a university emergency department. Allergy Asthma Proc. 2018;39(4):316–321.

33. Sicherer SH, Simons FER; Section on Allergy and Immunology. Epinephrine for first-aid management of anaphylaxis. Pediatrics. 2017;139(3):e20164006.

34. Xu YS, Kastner M, Harada L, et al. Anaphylaxis-related deaths in Ontario: a retrospective review of cases from 1986 to 2011. Allergy Asthma Clin Immunol. 2014;10(1):38.

35. Smith N, Lopez RA, Silberman M. Distributive shock. Updated November 15, 2019. Accessed April 29, 2020.

36. Arnold JJ, Williams PM. Anaphylaxis: recognition and management. Am Fam Physician. 2011;84(10):1111–1118. Accessed August 28, 2019.

37. Robinson M, Greenhawt M, Stukus DR. Factors associated with epinephrine administration for anaphylaxis in children before arrival to the emergency department. Ann Allergy Asthma Immunol. 2017;119(2):164–169.

38. Carrillo E, Hern HG, Barger J. Prehospital administration of epinephrine in pediatric anaphylaxis. Prehosp Emerg Care. 2016;20(2):239–244.

39. Fleming JT, Clark S, Camargo CA Jr, et al. Early treatment of food-induced anaphylaxis with epinephrine is associated with a lower risk of hospitalization. J Allergy Clin Immunol Pract. 2015;3(1):57–62.

40. Thomson H, Seith R, Craig S. Inaccurate diagnosis of paediatric anaphylaxis in three Australian emergency departments. J Paediatr Child Health. 2017;53(7):698–704.

41. Russell WS, Farrar JR, Nowak R, et al. Evaluating the management of anaphylaxis in US emergency departments: guidelines vs. practice. World J Emerg Med. 2013;4(2):98–106.

42. Alvarez-Perea A, Tanno LK, Baeza ML. How to manage anaphylaxis in primary care. Clin Transl Allergy. 2017;7:45.

43. Liyanage CK, Galappatthy P, Seneviratne SL. Corticosteroids in management of anaphylaxis; a systematic review of evidence. Eur Ann Allergy Clin Immunol. 2017;49(5):196–207.

44. Lee S, Bellolio MF, Hess EP, et al. Time of onset and predictors of biphasic anaphylactic reactions: a systematic review and meta-analysis. J Allergy Clin Immunol Pract. 2015;3(3):408–416.e1, e2.

45. Kim TH, Yoon SH, Hong H, et al. Duration of observation for detecting a biphasic reaction in anaphylaxis: a meta-analysis. Int Arch Allergy Immunol. 2019;179(1):31–36.

46. Shaker MS, Wallace DV, Golden DBK, et al.; Joint Task Force on Practice Parameters Reviewers. Anaphylaxis–a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis. J Allergy Clin Immunol. 2020;145(4):1082–1123.

47. Vale S, Smith J, Said M, et al. ASCIA guidelines for prevention of anaphylaxis in schools, pre-schools and childcare: 2015 update. J Paediatr Child Health. 2015;51(10):949–954.

48. Owusu-Ansah S, Badaki O, Perin J, et al. Under prescription of epinephrine to Medicaid patients in the pediatric emergency department. Glob Pediatr Health. 2019;6:2333794X19854960.

49. Clausen SS, Stahlman SL. Food-allergy anaphylaxis and epinephrine autoinjector prescription fills, active component service members, U.S. Armed Forces, 2007–2016. MSMR. 2018;25(7):23–29.

50. Portnoy J, Wade RL, Kessler C. Patient carrying time, confidence, and training with epinephrine autoinjectors: the RACE survey. J Allergy Clin Immunol Pract. 2019;7(7):2252–2261.

51. Warren CM, Zaslavsky JM, Kan K, et al. Epinephrine auto-injector carriage and use practices among US children, adolescents, and adults. Ann Allergy Asthma Immunol. 2018;121(4):479–491.



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