What is the recommended treatment for anaphylaxis?

Anaphylaxis Treatment Protocol

Epinephrine is the first-line and most critical treatment for anaphylaxis and should be administered immediately upon recognition of anaphylactic symptoms. 1, 2

First-Line Treatment

• Epinephrine administration:
  • Adults and children ≥30 kg: 0.3-0.5 mg of 1:1000 concentration (1 mg/mL) IM in the anterolateral thigh
  • Children <30 kg: 0.01 mg/kg (maximum 0.3 mg) of 1:1000 concentration IM in the anterolateral thigh 1
  • Delayed administration may be fatal 3
  • Prepare for potential second dose if symptoms persist or worsen 1

Positioning and Supportive Care

• Place patient in supine position with legs elevated (or Trendelenburg position for severe hypotension) 1
• Establish IV access immediately
• For hypotension: Administer fluid resuscitation with 1-2 liters of normal saline at 5-10 mL/kg in first 5 minutes 1
• Provide supplemental oxygen for respiratory symptoms or after multiple epinephrine doses 1
• Continuous cardiac monitoring, especially for high-risk patients 1

Adjunctive Therapies (Only after epinephrine administration)

1. Antihistamines:

   • H1 antagonists: Diphenhydramine 25-50 mg IV/IM/PO for cutaneous symptoms 1
   • H2 blockers: Famotidine 20 mg IV for urticaria 1

2. Bronchodilators:

   • Albuterol 2.5-5 mg via nebulizer for persistent bronchospasm 1

3. Corticosteroids:

   • Methylprednisolone 1-2 mg/kg IV every 6 hours or
   • Prednisone 0.5 mg/kg orally
   • May help prevent protracted or biphasic reactions 1

Monitoring and Observation

• Monitor vital signs, including blood pressure, heart rate, and oxygen saturation 1
• Observe patients until signs and symptoms have fully resolved 1
• Observation periods:
  • High-risk patients: Extended observation up to 6+ hours or hospital admission 1
  • Low-risk patients: May be discharged after 1-hour asymptomatic observation 1
  • 6-19% of pediatric patients require a second dose of epinephrine 1

High-Risk Factors for Biphasic Reactions

• Severe initial anaphylactic reaction
• Requirement of more than one epinephrine dose
• Wide pulse pressure
• Unknown anaphylaxis trigger
• Drug-triggered anaphylaxis in children 1
• Coexisting asthma, mast cell disorders, older age, cardiovascular disease 4

Patient Education and Follow-up

• Prescribe epinephrine auto-injector to be carried at all times 3
• Educate on proper use of epinephrine auto-injector 1, 3
• Instruct to activate emergency response system (call 911) for any recurrence 1
• Refer to allergist/immunologist for trigger identification and long-term management 1

Common Pitfalls to Avoid

• Delaying epinephrine administration - this is the most common and dangerous error 5
• Using IV route for initial epinephrine (IM is preferred except in severe shock) 6
• Relying on antihistamines or corticosteroids as first-line treatment 4
• Discharging patients too early without adequate observation
• Failing to prescribe auto-injector or provide proper education on its use
• Overlooking the need for allergist referral for long-term management

Remember that epinephrine is the cornerstone of anaphylaxis management, and no contraindications exist to its use in a life-threatening anaphylactic reaction 3.