Can Hydrocortisone Be Given in Anaphylaxis?
Hydrocortisone can be given in anaphylaxis, but only as adjunctive therapy after epinephrine has been administered first—it has no role in treating acute symptoms due to its slow onset of action (4-6 hours minimum) and should never delay or replace epinephrine. 1, 2
Critical First-Line Treatment
- Epinephrine is the only first-line treatment for anaphylaxis and must be administered immediately at 0.01 mg/kg of 1:1000 concentration (maximum 0.5 mg in adults, 0.3 mg in children) intramuscularly into the vastus lateralis. 2
- Delaying epinephrine administration is directly associated with anaphylaxis fatalities and increased risk of biphasic reactions. 2
- Do not administer antihistamines or corticosteroids as first-line treatment instead of epinephrine—this is a dangerous practice that can lead to delayed treatment of life-threatening symptoms. 3
Why Hydrocortisone Has Limited Acute Utility
Hydrocortisone works through a genomic mechanism that is inherently slow: 1
- It binds to glucocorticoid receptors on cell membranes
- The complex translocates to the nucleus
- It inhibits gene expression and production of new inflammatory mediators
- Clinical effects do not manifest for 4-6 hours after administration, regardless of route 1, 4
This mechanism means hydrocortisone cannot reverse acute anaphylactic symptoms such as hypotension, bronchospasm, or laryngeal edema. 1
When to Consider Hydrocortisone
Hydrocortisone may be considered as adjunctive therapy only after epinephrine and stabilization in specific circumstances: 2
- Patients with severe or prolonged anaphylaxis
- History of idiopathic anaphylaxis
- Underlying asthma
- Patients at increased risk of biphasic reactions (those requiring >1 dose of epinephrine) 1
The typical dose is 1-2 mg/kg of methylprednisolone equivalent (or hydrocortisone 100-200 mg IV). 3
Evidence on Preventing Biphasic Anaphylaxis
The evidence does not support hydrocortisone for preventing biphasic anaphylaxis: 2
- The 2020 Anaphylaxis Practice Parameter from the Journal of Allergy and Clinical Immunology specifically recommends against using glucocorticoids to prevent biphasic anaphylaxis in adults. 2
- A systematic review found that glucocorticoids demonstrated a nonsignificant inverse trend with biphasic anaphylaxis, but one study showed supplemental use of glucocorticoids with epinephrine resulted in worse outcomes. 1
- Studies showed glucocorticoids reduced length of hospital stay but did not prevent return visits to the emergency department. 1, 3
Practical Administration Guidelines
If you decide to administer hydrocortisone after epinephrine: 3
- Give hydrocortisone 1-2 mg/kg (or equivalent corticosteroid) every 6 hours
- Treatment should be stopped within 2-3 days, as all biphasic reactions reported to date have occurred within 3 days 1
- The rationale is empiric use for potential anti-inflammatory benefits, not acute symptom relief 1
Critical Pitfalls to Avoid
- Never delay epinephrine administration to give hydrocortisone first—this has been associated with fatalities. 3
- Do not rely on hydrocortisone to treat acute cardiovascular collapse or respiratory distress—it is ineffective for these life-threatening manifestations. 2
- Be aware that rare anaphylactoid reactions to hydrocortisone itself have been reported, though this is exceedingly uncommon. 5, 6, 7
The Bottom Line on Supplemental Therapies
The certainty of evidence around supplemental therapies (including glucocorticoids and antihistamines) in anaphylaxis management is very low. 1 While empiric use of hydrocortisone is prevalent and supported by many clinicians, no high-quality evidence demonstrates clear benefit when combined with epinephrine. 1 The decision to use hydrocortisone should be made after epinephrine has been given and the patient is being stabilized, particularly in those with risk factors for severe or biphasic reactions.