eMedicine Specialties > Emergency Medicine > Pediatric

Pediatrics, Anaphylaxis

Author: Jeffrey F Linzer Sr, MD, MICP, FAAP, FACEP, Associate Professor of Pediatrics and Emergency Medicine, Emory University School of Medicine; Associate Medical Director for Business Affairs and Compliance and EMS/Pre-Hospital Care Coordinator, Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine; Emergency Pediatric Group, Children's Healthcare of Atlanta at Egleston; Co-Medical Director and Consulting Staff, Children's Sedation Service, Children's Healthcare of Atlanta at Egleston
Contributor Information and Disclosures

Updated: Jan 10, 2008

Introduction

Background

Anaphylaxis is an acute, potentially life-threatening syndrome, with multisystemic manifestations resulting from the rapid release of inflammatory mediators.

The term anaphylaxis, derived from Greek for "contrary to protection," was coined by Charles R. Richet and Paul Portier in 1902 after their experiments showed a small, nonlethal dose of toxin caused rapid death in sensitized dogs. While the clinical presentation and management are the same, some authors use the term anaphylaxis for immunoglobulin E (IgE)–mediated reactions and anaphylactoid for non–IgE-mediated reactions. The term anaphylaxis syndrome is best used to describe the clinical event.

In children, foods can be a very significant trigger for IgE-mediated anaphylaxis. Milk, eggs, wheat, and soy (MEWS) as a group are the most common food allergens; however, peanuts and fish are among the most potent. Children can develop anaphylaxis from the fumes of cooking fish or residual peanut in a candy bar.

Other common triggers include preservatives (in food and drugs), medications (antibiotics), insect venom (bee sting), and bioactive substances (eg, blood, blood products). Environmental allergens such as pollens, molds, and dust mites are a less common and infrequent cause of anaphylaxis.

Non-IgE triggers include infection, opiates, radiocontrast dye, and exercise.

Pathophysiology

Both IgE and non-IgE activation of mast cells and basophils ignites a cascade that results in the release and production of several inflammatory and vasoactive substances. These bioactive materials include histamine, tryptase, heparin, prostaglandins (PGD2, PGF2), leukotrienes (LTC4, LTD4, and LTE4), cytokines (TNF‑α), and platelet-activating factor (PAF). In anaphylaxis, these substances most commonly involve the skin, respiratory, cardiovascular, and gastrointestinal systems. As a result, urticaria, angioedema, bronchospasm, bronchorrhea, laryngospasm, increased vascular permeability and decreased vascular tone, and bloody diarrhea can develop.
 
The most common cause of mediator release is due to an IgE-mediated reaction. A previously sensitized B lymphocyte produces IgE against a specific antigen. The IgE resides on the mast cells and basophils. When the specific antigen, or one similar to it, binds to the high affinity FcεRI-α receptor of the immunoglobulin, mast cell and basophil degranulation occurs.
 
Non-IgE mediator release can be triggered by several different mechanisms including stimulation of the complement cascade to produce C3a, C4a, and C5a anaphylatoxin, neuropeptide and cytokine activity, and direct contact (kallikrein-kinin system) stimulation by certain agents (eg, opiates, radiocontrast media).
 
Many of the clinical presentations seen in anaphylaxis are due to activation of multiple histamine receptors1 For example, acute bronchospasm (wheezing, dyspnea) is a result of the interaction between H1 and H2 receptor activity; bronchial smooth muscle constriction and increased mucus viscosity from H1 receptor activity and H2 activity causes increased mucus production. The combination of H1 and H2 receptor stimulation results in increased vascular permeability, flushing, hypotension, tachycardia, and headache. H1 and H3 activity results in cutaneous itch and nasal congestion.
 
However, histamine is not the only agent that causes the symptoms in anaphylaxis2 Prostaglandin, leukotrienes, and PAF all contribute to the bronchoconstriction, vascular changes, and changes in vascular capacitance (increased vascular permeability and vasodilatation).

Frequency

United States

Frequency estimates are difficult to determine. Part of the reason may be due to the methodology used by researchers (differing criteria and populations), part likely is due to underreporting, and part is likely due to lack of consistent diagnoses. In a review of the literature by Neugut et al, the overall occurrence of anaphylaxis in the US ranges from 1.24-16.8%.3 However, a working group on anaphylaxis from the AmericanCollege of Allergy, Asthma, and Immunology estimated the lifetime prevalence at 0.5-2%.4

International

Prevalence is similar to that in the United States.4

Mortality/Morbidity

Risk of death due to respiratory and cardiovascular complications is significant. Mortality rate estimates vary from 100 to more than 500 cases per year in the United States. The estimated death rate is 0.002%.3

Race

While asthma is more prevalent and has a higher mortality rate in African American children, race does not appear to affect the frequency of having anaphylaxis5

Sex

One retrospective study showed that males younger than 15 years were approximately twice as likely to have anaphylaxis compared with girls (odds ratio 1.917; 95% confidence interval, 1.294 –3.003; P>0.001)6 This balance appears to reverse in older patients.4

Age

Bohlke and colleagues estimated the rate of anaphylaxis in children at the rate of 10.5 per 100,000 person-years7

Clinical

History

Anaphylaxis is a range of signs and symptoms from hives and wheezing to cardiovascular collapse and death. At least 2 organ systems (most commonly skin, respiratory, cardiovascular, gastrointestinal systems) need to be involved to make the diagnosis8,9

  • Usually, cutaneous symptoms present first.
  • Often, a history of exposure to a known trigger is given, (eg, bee sting, peanut ingestion, antibiotic administration). At times, the inciting agent may be unknown or unclear.
  • Symptoms may develop slowly and insidiously over several hours or may rapidly progress over several minutes. Parenteral agents generally have a faster onset of symptoms than ingested ones.
  • Children may not be able to express the initial symptoms of anaphylaxis. They may initially have apparent discomfort or a generalized irritability. Additionally, the child may not be able to identify the triggering agent (eg, food) even when known to the parent or caretaker.
  • Between 5% and 20% of patients may experience a recurrence of anaphylaxis 8-12 hours after the initial presentation10

Physical

Initial symptoms may include an awareness that "something isn't right"; a tingling sensation in the mouth; itchy, watery nose and eyes; and/or the feeling of being warm and flushed.

  • Cutaneous (skin)
    • Urticaria (hives, welts, "whelps")
    • Pruritus (itching)
    • Angioedema (swelling) of the face, extremities, or both
  • Ear, nose, mouth
    • Nasal congestion
    • Sneezing
    • Rhinorrhea (runny nose)
    • Metallic taste
    • Laryngeal edema (throat tightness)
  • Respiratory
    • Cough
    • Wheezing
    • Hoarseness
    • Chest pain (respiratory symptom in children)
    • Shortness of breath
    • Stridor ("crowing" inspiratory sound)
  • Gastrointestinal
    • Nausea/vomiting
    • Abdominal cramps
    • Diarrhea (at times bloody)
  • Cardiovascular
    • Tachycardia (rapid heart rate)
    • Arrhythmias (irregular heart beat)
    • Decreased peripheral perfusion
    • Hypotension (low blood pressure - usually a late finding in children)
  • Central nervous system
    • Dizziness
    • Syncope (fainting)
    • Altered mental status
    • Coma

Causes

The following is only meant to be illustrative of the more common triggers but should not be considered an exhaustive listing. These triggering agents may cause an IgE- or non–IgE-mediated anaphylaxis.

  • Foods (most common cause in children) - Milk, eggs, wheat, soy, fish, shell fish, legumes (peanuts), nuts
  • Medicinals - Antibiotics (penicillins, cephalosporins), local anesthetics (lidocaine), analgesics (aspirin, nonsteroidal anti-inflammatory drugs [ibuprofen], opiates [codeine, morphine]), dextran, radiocontrast media
  • Biologicals - Venoms (bee sting, ant or snake bite), blood and blood products, vaccines, allergen extracts
  • Preservatives and additives - Metabisulfite, monosodium glutamate
  • Other -Latex, unknown/idiopathic

More on Pediatrics, Anaphylaxis

Overview: Pediatrics, Anaphylaxis
Differential Diagnoses & Workup: Pediatrics, Anaphylaxis
Treatment & Medication: Pediatrics, Anaphylaxis
Follow-up: Pediatrics, Anaphylaxis
References
Further Reading

References

  1. Simons EFR. Advances in H1-antihistamines. N Engl J Med. Nov 2004;351 (21):2203-17. [Medline].

  2. Ogawa Y, Grant JA. Mediators of anaphylaxis. Immunol Allergy Clin North Am. May 2007;27(2):249-60, vii. [Medline].

  3. Neugut AI, Ghatak AT, Miller RL. Anaphylaxis in the United States: an investigation into its epidemiology. Arch Intern Med. Jan 8 2001;161(1):15-21. [Medline][Full Text].

  4. Lieberman P, Camargo CA Jr, Bohlke K, et al. Epidemiology of anaphylaxis: findings of the American College of Allergy, Asthma and Immunology Epidemiology of Anaphylaxis Working Group. Ann Allergy Asthma Immunol. Nov 2006;97(5):596-602. [Medline].

  5. Sheikh A, Alves B. Age, sex, geographical and socio-economic variations in admissions for anaphylaxis: analysis of four years of English hospital data. Clin Exp Allergy. Oct 2001;31(10):1571-6. [Medline].

  6. Jirapongsananuruk O, Bunsawansong W, Piyaphanee N, Visitsunthorn N, Thongngarm T, Vichyanond P. Features of patients with anaphylaxis admitted to a university hospital. Ann Allergy Asthma Immunol. Feb 2007;98(2):157-62. [Medline].

  7. Bohlke K, Davis RL, DeStefano F, Marcy SM, Braun MM, Thompson RS. Epidemiology of anaphylaxis among children and adolescents enrolled in a health maintenance organization. J Allergy Clin Immunol. Mar 2004;113(3):536-42. [Medline].

  8. 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 Disease/Food Allergy and Anaphylaxis Network symposium. J Allergy Clin Immunol. Feb 2006;117(2):391-7. [Medline].

  9. Joint Task Force on Practice Parameters, American Academy of Allergy, Asthma and Immunology; American College of Allergy,Asthma and Immunology and Joint Council of Allergy, Asthma and Immunology. The diagnosis and management of anaphylaxis: an updated practice parameter. J Allergy Clin Immunol. Mar 2005;115(3 Suppl 2):S483-523. [Medline].

  10. Kobrynski LJ. Anaphylaxis. Clin Ped Emerg Med. 2007;8:110-16. [Full Text].

  11. Schwartz LB, Irani AM. Serum tryptase and the laboratory diagnosis of systemic mastocytosis. Hematol Oncol Clin North Am. Jun 2000;14(3):641-57. [Medline].

  12. Simons FE, Roberts JR, Gu X, Simons KJ. Epinephrine absorption in children with a history of anaphylaxis. J Allergy Clin Immunol. Jan 1998;101(1 Pt 1):33-7. [Medline].

  13. Simons FE, Gu X, Simons KJ. Epinephrine absorption in adults: intramuscular versus subcutaneous injection. J Allergy Clin Immunol. Nov 2001;108(5):871-3. [Medline].

  14. American Heart Association. Part 12: Pediatric Advanced Life Support. Circulation. 2005;112(Suppl 1):IV-167-87. [Full Text].

  15. Lin RY, Curry A, Pesola GR, Knight RJ, Lee HS, Bakalchuk L. Improved outcomes in patients with acute allergic syndromes who are treated with combined H1 and H2 antagonists. Ann Emerg Med. Nov 2000;36(5):462-8. [Medline].

  16. Lieberman P. Biphasic anaphylactic reactions. Ann Allergy Asthma Immunol. Sep 2005;95(3):217-26. [Medline].

  17. Lieberman P. Anaphylaxis and anaphylactoid reactions. In: Adkinson NF, Yunginger JW, Busse MW, et al, eds. Middleton's Allergy Principles and Practice. Vol 2. 6th ed. Philadelphia, PA: Mosby; 2003:1497-522.

Further Reading

AAAAI Board of Directors. Position Statement: Anaphylaxis in schools and other child-care settings. American Academy of Allergy Asthma & Immunology. Available at http://www.aaaai.org/media/resources/academy_statements/position_statements/ps34.asp. Accessed August 19, 2007.

Keywords

anaphylaxis, allergic reaction, anaphylactic shock, anaphylactoid reaction, anaphylaxis syndrome, bee sting, drug allergy, food allergens, food allergy, immediate hypersensitivity reaction, latex allergy, medication allergy, peanut allergy, nut allergy, penicillin allergy, severe allergic reaction, venomous sting/bite

Contributor Information and Disclosures

Author

Jeffrey F Linzer Sr, MD, MICP, FAAP, FACEP, Associate Professor of Pediatrics and Emergency Medicine, Emory University School of Medicine; Associate Medical Director for Business Affairs and Compliance and EMS/Pre-Hospital Care Coordinator, Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine; Emergency Pediatric Group, Children's Healthcare of Atlanta at Egleston; Co-Medical Director and Consulting Staff, Children's Sedation Service, Children's Healthcare of Atlanta at Egleston
Jeffrey F Linzer Sr, MD, MICP, FAAP, FACEP is a member of the following medical societies: American Academy of Pediatrics, American College of Allergy, Asthma and Immunology, American College of Emergency Physicians, and Medical Association of Georgia
Disclosure: Nothing to disclose.

Medical Editor

Kirsten A Bechtel, MD, Assistant Professor of Pediatrics, Department of Pediatrics, Yale University School of Medicine; Consulting Staff, Department of Pediatric Emergency Medicine, Yale-New Haven Children's Hospital
Kirsten A Bechtel, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

Wayne Wolfram, MD, MPH, Clinical Associate Professor, Departments of Pediatrics, Children's Hospital and University of Cincinnati
Wayne Wolfram, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American Academy of Pediatrics, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Richard G Bachur, MD, Assistant Professor of Pediatrics, Harvard Medical School; Associate Chief and Fellowship Director, Attending Physician, Division of Emergency Medicine, Children's Hospital of Boston
Richard G Bachur, MD is a member of the following medical societies: American Academy of Pediatrics, Society for Academic Emergency Medicine, and Society for Pediatric Research
Disclosure: Nothing to disclose.

 
 
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