Anaphylaxis: Difference between revisions
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*Uniphasic response, followed by asymptomatic period of hour or more, then return of symptoms
*Uniphasic response, followed by asymptomatic period of hour or more, then return of symptoms
*The second phase does not necessarily resemble the first!
*The second phase does not necessarily resemble the first!
*More likely with a severe initial presentation, hypotension, and recurrent epinephrine dosing requirements in the emergency department<ref>Ellis AK, Day JH: Incidence and characteristics of biphasic anaphylaxis: A prospective evaluation of 103 patients. Ann Allergy Asthma Immunology. 2007; 98:64-69</ref>
*More likely with a severe initial presentation or repeated epinephrine doses. Additionally hypotension, widened pulse pressure, unknown trigger, and drug trigger in children<ref>Ellis AK, Day JH: Incidence and characteristics of biphasic anaphylaxis: A prospective evaluation of 103 patients. Ann Allergy Asthma Immunology. 2007; 98:64-69</ref> <ref name="aaaai">
*Little evidence to support the use of discharge steroids to prevent a biphasic reaction
*Little evidence to support the use of discharge steroids to prevent a biphasic reaction
*0.4% of patients with anaphylaxis had a rebound event while in the ED<ref name="biphasic"/>
*0.4% of patients with anaphylaxis had a rebound event while in the ED<ref name="biphasic"/>

Revision as of 12:46, 23 August 2022

Background

  • Type I hypersensitivity reaction that is either severe in nature or having two or more organ systems involved.
  • Clinically Anaphylaxis and its treatment is virtually identical whether it is the traditional IgE dependent anaphylaxis reaction (vast majority), or the IgE independent anaphylactoid reaction
  • Precipitants
    • Food (most common)
    • Medications
    • Insect stings
    • Latex
    • Aerobic exercise
    • Idiopathic (rare)

Clinical Features

Raised urticaria
Angioedema of tongue
Angioedema of face.
  • Cutaneous symptoms (90%)
  • Respiratory symptoms (70%)
  • Gastrointestinal symptoms (40%)
    • Abdominal pain
    • Nausea, vomiting
    • Diarrhea
  • Cardiovascular symptoms (35%)
  • Central Nervous System
    • Uneasiness
    • Altered mental status
    • Headache, dizziness, confusion
    • Syncope

Expected Course

Uniphasic (80-90%)

  • Symptoms peak within 30 minutes to 1 hour after onset, resolve within 30 minutes to 1 hour of receiving treatment[1]

Biphasic (10-20%)

Biphasic reactions are rare and can occur anywhere from 10 minutes up to six days after an initial reaction.[2]

  • Uniphasic response, followed by asymptomatic period of hour or more, then return of symptoms
  • The second phase does not necessarily resemble the first!
  • More likely with a severe initial presentation or repeated epinephrine doses. Additionally hypotension, widened pulse pressure, unknown trigger, and drug trigger in children[3] Cite error: Closing </ref> missing for <ref> tag[4]

Criterion 1 (90% of patients)

  • Acute onset of an illness involving the skin, mucosal tissue, or both AND at least one of the following:
    • Respiratory Compromise
    • Reduced blood pressure or associated symptoms (Syncope, Dizziness)

Criterion 2 (10-20% of patients)

  • TWO OR MORE of the following that occur rapidly after exposure to a LIKELY allergen for that patient
    • Involvement of the skin-mucosal tissue (hives, swollen lips-tongue-uvula)
    • Respiratory compromise
    • Hypotension or associated symptoms
    • Persistent gastrointestinal symptoms: (vomiting, diarrhea, crampy abdominal pain)

Criterion 3

  • Hypotension after exposure to a KNOWN allergy for that patient (minutes to hours):
    • Adults: systolic blood pressure (SBP) <90 mmHg or >30% reduction from baseline
    • Pediatrics
      • 1 month - 1 year: SBP <70 mmHg
      • 1 year - 10 years: SBP <(70 mmHg + [2 x age])
      • 11 years - 17 years: SBP <90 mmHg

Management

  • Epinephrine
    • 1:1000 IM 0.3 - 0.5mg (0.3 - 0.5mL) every 5 - 15 minutes[5][6]
    • Give as soon as possible
    • Always IM initially [7]
    • If response to IM is inadequate: give epinephrine infusion 1:10,000 2 - 10 µg/min
    • How to make a quick epinephrine drip: Take your code-cart epinephrine (it does not matter if it is 1:1,000 or 1:10,000) and inject 1mg into a liter bag of NS. Final concentration is 1mcg/ml. Run at 1cc/min and titrate to effect.
  • Pediatric: Epinephrine 1:1000 0.01mg/kg (max 0.5mg) IM every 5 to 15 minutes
    • IV infusion: 0.05 - 1 mcg/kg/min
  • Supplemental oxygen
  • Normal saline bolus
    • If unresponsive to epinephrine assume distributive shock and give 1 - 2 liters of normal saline
  • Also consider
    • Albuterol for bronchospasm resistant to IM epinephrine
    • Antihistamines (for symptom control AFTER hemodynamically stable)
      • Diphenhydramine: 25 to 50mg IV (1mg/kg in children)
      • Ranitidine: 50mg IV (0.5mg/kg in children) (has been found to improve urticaria but not angioedema at 2 hours[8])
      • AVOID promethazine as this can worsen hypotension
    • Glucocorticoid
      • MAY blunt biphasic reaction although little evidence to support usage[9]
      • Methylprednisolone: 125mg IV (2mg/kg in children)
      • Dexamethasone: 10mg IV or PO (0.6mg/kg in children)
    • Glucagon
      • 1 - 5mg IV over 5 minutes followed by infusion of 5 - 15 µg/min[10]
      • If taking beta-blocker AND unresponsive to epinephrine
    • Consider adding additional pressor support if persistent hypotension present

Disposition

Admit

  • Severe and moderate presentations especially if symptoms did not respond promptly to epinephrine or required repeat dosing
  • Labs that may be requested by allergist/admitting team if uncertain diagnosis
    • Histamine level - serum elevation 30-60 min following anaphylaxis, window easily missed
    • Tryptase - peaks at 2-4 hrs, remains elevated 6-12 hrs

Discharge

  • Consider discharge after 1 hour observation per AAAAI recommendations if no severe symptoms and no repeat epinephrine doses [13]
    • NPV of 1-hour observation was 95%, with NPV for biphasic anaphylaxis after >6 hours of observation of 97.3% [14]
  • Classical teaching Symptom-free for at least 4 hours and mild initial presentation
  • Send home with an epinephrine autoinjector! (Epi-Pen)
  • Up to 6% of the people with anaphylaxis have a repeat ED visit for anaphylaxis within 7 days[15]

See Also

References

  1. ↑ Ewan PW. ABC of allergies – Anaphylaxis, BMJ 1998; 316: 1442-1445
  2. ↑ Milne K. Biphasic Allergic Reactions: Observation, Treatment Guidelines http://www.acepnow.com/article/biphasic-allergic-reactions-observation-treatment-guidelines/
  3. ↑ Ellis AK, Day JH: Incidence and characteristics of biphasic anaphylaxis: A prospective evaluation of 103 patients. Ann Allergy Asthma Immunology. 2007; 98:64-69
  4. ↑ Lieberman P et al. The diagnosis and management of anaphyalxis: An updated practice parameter, J Allergy Clin Immunol 2005;115;3:S483-S523
  5. ↑ Dhami S. et al. Management of anaphylaxis: a systematic review. Allergy. 69 (2014) 168–175. http://onlinelibrary.wiley.com/store/10.1111/all.12318/asset/all12318.pdf?v=1&t=hrspdbpk&s=8067bfd5903c7ffebf4a274f062a71633ebe0507
  6. ↑ Sheikh A, Shehata YA, Brown SGA, Simons FER. Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock. Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD006312. DOI:10.1002/14651858.CD006312.pub2
  7. ↑ Simons FER, Gu X, Simons KJ. Epinephrineabsorption in adults: Intramuscular versus subcutaneous injection, J Allergy Clin Immunol 2001;108:871-3
  8. ↑ Lin, RY et al. Improved Outcomes in Patients With Acute Allergic Syndromes Who Are Treated With Combined H1 and H2 Antagonists. Annals of Emergency Medicine. 36:5 NOVEMBER 2000.
  9. ↑ Choo KJ, Simons E, Sheikh A: Glucocorticoids for the treatment of anaphylaxis: Cochrane systematic review. Allergy 2010; 65:1205-1211.
  10. ↑ Campbell RL, et al. Emergency department diagnosis and treatment of anaphylaxis: a practice parameter. Ann Allergy Asthma Immunol. 2014; 113:599e608.
  11. ↑ Schummer et al. The Pivotal Role of Vasopressin in Refractory Anaphylactic Shock. Anesthesia & Analgesia: August 2008 - Volume 107 - Issue 2 - pp 620-624.
  12. ↑ Dünser et al. Treatment of Anaphylactic Shock: Where Is the Evidence? Anesthesia & Analgesia: August 2008 - Volume 107 - Issue 2 - pp 359-361
  13. ↑ 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; 145:1082. https://www.aaaai.org/Aaaai/media/Media-Library-PDFs/Professional%20Education/Podcasts/Anaphylaxis-2020-grade-document.pdf
  14. ↑ Shaker M, Wallace D, Golden DBK, Oppenheimer J, Greenhawt M. Simulation of health and economic benefits of extended observation of resolved anaphylaxis. JAMA Netw Open 2019;2:e1913951.
  15. ↑ Grunau BE et al. Incidence of Clinically Important Biphasic Reactions in Emergency Department Patients With Allergic Reactions or Anaphylaxis. Ann Emerg Med. 2013 Nov 13
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