Does treatment of an allergic reaction in the emergency department (ED) require a prednisone taper upon discharge?

Treatment of Allergic Reactions in the ED: Prednisone Taper Requirements

Prednisone tapers are not routinely required for most patients discharged from the emergency department after treatment for allergic reactions. 1

Evidence-Based Approach to Allergic Reaction Management

Initial Treatment in the ED

• Epinephrine is the cornerstone first-line treatment for anaphylaxis, administered intramuscularly into the anterolateral thigh 2
• Antihistamines (H1 blockers like diphenhydramine) are appropriate for mild allergic reactions and as adjunctive therapy for anaphylaxis 1
• Systemic corticosteroids may be given for severe anaphylaxis, asthma, and significant generalized urticaria/angioedema 1

Discharge Considerations

For Mild-to-Moderate Allergic Reactions:

• No prednisone taper is necessary for most patients with mild-to-moderate allergic reactions
• Single-dose or short-course corticosteroid treatment in the ED is typically sufficient 1

For Severe Reactions/Anaphylaxis:

• The 2020 Joint Task Force Practice Parameter on anaphylaxis does not recommend routine prednisone tapers upon discharge 1
• The focus should be on:
  • Prescribing epinephrine auto-injectors (2 doses)
  • Providing an anaphylaxis emergency action plan
  • Arranging follow-up with an allergist 1

Special Considerations

Observation Period

• Patients with resolved mild allergic reactions can typically be discharged after 1 hour of observation 1
• For anaphylaxis, observation for 4-6 hours after symptom resolution is recommended 1
• Longer observation (including hospital admission) may be appropriate for patients with:
  • Severe initial presentation
  • Need for >1 dose of epinephrine
  • Wide pulse pressure
  • Unknown anaphylaxis trigger 1

Risk of Biphasic Reactions

• Biphasic reactions can occur in 1-20% of anaphylaxis cases, typically around 8 hours after the initial reaction (but can occur up to 72 hours later) 1
• There is no compelling evidence that corticosteroid tapers prevent biphasic reactions 3
• The 2020 anaphylaxis practice parameter states: "We did not find clear evidence to support the role of glucocorticoids and/or antihistamines to prevent biphasic anaphylaxis" 1

Common Pitfalls to Avoid

1. Overreliance on corticosteroids: Many ED providers administer corticosteroids (51.8% in one study) 4 but underutilize epinephrine for anaphylaxis (only 15.9% of anaphylaxis cases in the same study)

2. Assuming prednisone tapers are always needed: This practice is not supported by current guidelines for most allergic reactions 1

3. Focusing on steroids rather than epinephrine: Epinephrine remains the most important life-saving intervention for anaphylaxis, yet studies show it is underutilized in emergency settings 5, 6

4. Neglecting proper discharge planning: All patients with anaphylaxis should receive epinephrine auto-injectors, an action plan, education about trigger avoidance, and referral to an allergist 1

By following these evidence-based recommendations, emergency physicians can provide optimal care for patients with allergic reactions while avoiding unnecessary prednisone tapers that add complexity and potential side effects without clear benefit.