What is the role of hydrocortisone in the treatment of anaphylaxis?

Hydrocortisone Has No Role in Acute Anaphylaxis Management

Glucocorticoids, including hydrocortisone, have no role in treating acute anaphylaxis due to their slow onset of action and lack of evidence supporting their efficacy in this setting. 1, 2

First-Line Treatment for Anaphylaxis

The management of anaphylaxis follows a clear hierarchy of interventions:

1. Epinephrine: Intramuscular epinephrine is the definitive first-line treatment for anaphylaxis.

   • Administer into the vastus lateralis (anterolateral thigh) at a dose of 0.01 mg/kg (maximum 0.5 mg in adults, 0.3 mg in children) 1, 2
   • For autoinjectors: 0.15 mg for patients 10-25 kg, 0.3 mg for patients >25 kg 2
   • Delay in administering epinephrine is associated with anaphylaxis fatalities and increased risk of biphasic reactions 1

2. Supportive measures:

   • Position patient supine or Trendelenburg if hypotensive 2
   • Administer fluid resuscitation for hypotension (20 mL/kg bolus of normal saline) 2
   • Provide supplemental oxygen for respiratory symptoms 1, 2

The Myth of Hydrocortisone in Anaphylaxis

Despite common practice, glucocorticoids like hydrocortisone:

• Have no proven role in treating acute anaphylaxis 1, 2
• Work with a slow onset of action (4-6 hours after administration) 1
• Do not address the life-threatening manifestations of anaphylaxis 1
• Are not recommended to prevent biphasic anaphylaxis, as multiple studies and systematic reviews have not demonstrated clear evidence of benefit 1

Appropriate Adjunctive Therapies

After epinephrine administration, consider:

• H1 antihistamines (e.g., diphenhydramine 25-50 mg IV/IM for adults): Only effective for cutaneous symptoms (urticaria, pruritus, flushing) 1, 2
• H2 antihistamines (e.g., ranitidine 50 mg IV for adults): May provide additional benefit when combined with H1 antagonists 2
• Bronchodilators (e.g., albuterol 2.5-5 mg via nebulizer): For bronchospasm resistant to epinephrine 2

Observation and Follow-up

• Monitor patients for at least 4-6 hours after symptom resolution 2
• Consider extended observation (up to 24 hours) for severe reactions requiring multiple epinephrine doses 2
• Be vigilant for biphasic reactions, which can occur up to 72 hours later (mean 11 hours) 1
• Any patient suspected of having anaphylaxis should be sent to the nearest emergency department 1

Common Pitfalls to Avoid

1. Delaying epinephrine: Never delay epinephrine administration to give antihistamines or corticosteroids 1, 2
2. Overreliance on corticosteroids: Despite widespread use, there is no evidence supporting their efficacy in acute anaphylaxis 1
3. Inadequate observation: Failure to monitor for biphasic reactions can lead to missed recurrences 1
4. Subcutaneous epinephrine: Intramuscular administration in the anterolateral thigh provides optimal absorption 1

Recent research from the Cross-Canada Anaphylaxis Registry actually found that patients who received prehospital corticosteroids were more likely to require intravenous fluids in the emergency department and to be admitted to the hospital 3, further questioning their benefit in anaphylaxis management.

While hydrocortisone may be commonly administered in clinical practice during anaphylaxis management, the evidence clearly shows it has no role in addressing the acute, life-threatening aspects of anaphylaxis and should not delay or replace epinephrine administration.