Acute Allergic Reaction and Anaphylaxis (> 6 months)

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Acute Allergic Reaction and Anaphylaxis (> 6 months)
Inclusion Criteria
  • Clinical concern for allergic or anaphylatic reaction
Exclusion Criteria
  • History of severe airway abnormality, surgery or tracheostomy
  • Pregnancy

Consider allergy consult

Serum ß-tryptase within 15 min to 3 hours after presentation, consider treating as anaphylaxis, consider allergy/immunology consult

History of previous near fatal anaphylaxis?

Establish vascular access

Epinephrine injection

Minimum 12 hour observation

Resolution of symptoms?


Upper airway obstruction?

Poor perfusion or hypotension?

Diphenhydramine or Cetirizine for symptomatic relief of itching or urticaria

Biphasic risk factors?

Minimum 2 hour observation

Meets discharge criteria?

Albuterol neb

Bolus and prepare for large volume infusions, Epinephrine infusion, Trendelenburg position, admit to ICU vs. medical unit admission based on response to therapy

NS Bolus
Epinephrine infusion

Nebulized Racemic Epinephrine, prepare for intubation, consider consulting advanced airway provider, ICU vs. medical unit admission based on response to therapy

Racemic epinephrine 2.25% inhalation solution

Meets ICU criteria?

Ongoing airway or vital sign instability?

Continued poor perfusion?

Admit to ICU

Patient supplied with and trained to use an epinephrine autoinjector, follow up with PMD within 2 days

Admit to Floor

Discharge criteria

  • Well defined disease process with improvement
  • Anaphylaxis emergency plan in place
  • Prescription for epinephrine auto-injector
  • Counseling regarding use of medic alert tag
  • Counseling regarding allergen identification and avoidance
  • Reassuring vital signs
  • Tolerating PO
  • Well-appearing
  • No social/family concerns
  • Reliable follow up in 24 hours
  • Patient/Caregivers comfortable and understand discharge plan
  • Provider comfortable with outpatient therapy

Biphasic risk factors

  • Previous biphasic episode
  • Delayed administration of epinephrine (> 1 hr)
  • Slow resolution of initial symptoms
  • Patient with complex medical history placing them at increased risk of a poor outcome

Epinephrine auto-injector

  • < 30kg Epipen Jr (0.15mg, 2-Pak)
  • >30 kg Epipen (0.3 mg, 2-Pak)


  • There is no evidence that steroids effect the initial signs and symptoms of anaphylaxis OR prevent biphasic reactions

Consider second vasopressor and Glucagon 20-30 mcg/min (max 1mg in children, 5 mg in adults) over 5 min followed by infusion 5-15 mcg/min, anti-emetic

ALS / PALS, remove affecting antigen or medication immediately

Are 1 of the following 3 criteria present?

Criteria 1

  • Acute onset of an illness (minutes to hours) with involvement of the skin, mucosa, or both (eg. generalized hives, pruritus or flushing, swollen lips-tongue-uvula)
    • Respiratory compromise
    • Reduced BP or associated symptoms of end-organ dysfunction

Criteria 2

  • 2 or more of the following that occur rapidly (minutes to hours) after exposure to a likely allergen
    • Involvement of the skin-mucosa
    • Respiratory compromise
    • Reduced BP or associated symptoms
    • Persistent gastrointestinal symptoms

Criteria 3

  • Reduced BP after exposure to at patient's known allergen

H2 antihistamines

  • There is no evidence that H2 blockers have any effect on anaphylaxis OR urticaria

Diphenhydramine suspension
Diphenhydramine injection

Repeat IM Epinepherine OR Epinephrine infusion (0.01 mcg/kg/min)