Prednisone Dosage for Allergic Reactions
For acute allergic reactions, prednisone should be dosed at 1 mg/kg daily (maximum 60-80 mg) for 2-3 days as adjunctive therapy after epinephrine administration. 1, 2
Severity-Based Dosing Algorithm
Mild Allergic Reactions (localized urticaria, mild pruritus)
- H1 and H2 antihistamines are first-line treatment without requiring corticosteroids 1
- If symptoms persist or worsen despite antihistamines, consider prednisone 20 mg orally every 12 hours for 4 days 3
- This lower-dose "burst" regimen (20 mg twice daily) significantly improves symptom resolution compared to antihistamines alone, with itch scores dropping from 8.1 to 1.3 at 2 days 3
Moderate to Severe Allergic Reactions (extensive urticaria, angioedema without airway compromise)
- Prednisone 1 mg/kg daily (maximum 60-80 mg) for 2-3 days 1, 2
- For antihistamine-resistant chronic urticaria, prednisone 25 mg/day for 3 days induces remission in approximately 47% of patients 4
- A second 3-day course can be attempted if initial response is temporary, achieving remission in an additional 9% of patients 4
Anaphylaxis (severe, life-threatening reaction)
- Epinephrine is first-line treatment; prednisone is adjunctive only 1
- After epinephrine stabilization, administer prednisone 1 mg/kg (maximum 60-80 mg) orally or methylprednisolone 1 mg/kg (maximum 60-80 mg) IV 1
- Continue prednisone daily for 2-3 days after discharge to prevent biphasic reactions 1, 2
Pediatric Dosing
- Weight-based dosing: 1 mg/kg daily (maximum 60 mg) 2
- Same 2-3 day duration applies 1, 2
- For children 10-25 kg with anaphylaxis, ensure epinephrine 0.15 mg IM is given first 1
Critical Clinical Considerations
Duration and Tapering
- Short courses of 2-3 days do NOT require tapering 2
- Courses shorter than 2 weeks generally do not cause adrenal suppression 2
- However, if treating extensive dermatologic reactions requiring longer courses (>2 weeks), a gradual taper over 3-4 weeks is essential to prevent rebound flares 5, 6
Common Pitfalls to Avoid
- Never use prednisone as monotherapy for anaphylaxis—epinephrine must be administered first 1
- Corticosteroids have delayed onset (hours), making them ineffective for immediate symptom control 1
- Short-term adverse effects include hyperglycemia, hypertension, mood changes, and insomnia 2
- For courses <2 weeks, these effects are generally well-tolerated 2
When Corticosteroids May Not Be Indicated
- Isolated mild urticaria responsive to antihistamines alone 1
- Patients with active peptic ulcer disease or uncontrolled diabetes should be treated with caution 3
- Consider alternative immunosuppression if frequent courses are needed (>3-4 times yearly) 2
Follow-Up Management
- All patients should follow up with primary care within 1 week 1, 2
- Prescribe epinephrine auto-injector (2 doses) for any patient with moderate-severe reaction 1
- Refer to allergist for: recurrent reactions, unclear triggers, or need for frequent steroid courses 1, 2
- Continue H1 antihistamines (diphenhydramine every 6 hours or non-sedating alternative) and H2 antihistamines (ranitidine twice daily) for 2-3 days after prednisone course 1
Special Populations
Elderly or Comorbid Patients
- Consider lower doses to minimize adverse effects, though specific dosing adjustments are not well-established 2
- Monitor for drug interactions, particularly with diabetes medications and antihypertensives 2