What dose of prednisone is used for poison ivy?

Prednisone Dosing for Poison Ivy Dermatitis

For poison ivy dermatitis, a prednisone dosage of 0.5-1 mg/kg/day for 14-21 days is recommended, with longer courses (including a taper) being more effective than short courses for severe cases.

Assessment of Severity

The appropriate prednisone dose depends on the severity of the poison ivy dermatitis:

Mild Cases

• Limited area (<10% body surface area)
• Minimal symptoms
• No systemic involvement
• Management: Typically managed with topical treatments; oral prednisone often not necessary

Moderate Cases

• 10-30% body surface area affected
• Significant pruritus and discomfort
• Management: Prednisone 0.5 mg/kg/day for 14 days

Severe Cases

• 30% body surface area affected

• Intense symptoms limiting self-care activities
• Facial or genital involvement
• Management: Prednisone 1 mg/kg/day for 14-21 days with taper

Recommended Dosing Regimen

For severe poison ivy dermatitis, evidence supports the following approach:

1. Initial dose: 40-60 mg daily for 5 days 1
2. Followed by taper:
   • 30 mg daily for 2 days
   • 20 mg daily for 2 days
   • 10 mg daily for 2 days
   • 5 mg daily for 4 days
   • Total duration: 15 days

Evidence-Based Rationale

Research shows that longer courses of prednisone (14-21 days) are more effective than shorter courses (5-7 days) for severe poison ivy dermatitis 1, 2. A randomized controlled trial demonstrated that patients receiving a longer course regimen were significantly less likely to require additional medications (22.7% vs. 55.6%) 1.

The 2024 AHA and Red Cross Guidelines for First Aid note that the combination of systemic corticosteroids and high-potency topical corticosteroids reduced the duration of itching in poison ivy dermatitis, while low-potency corticosteroids were not associated with symptom improvement 3.

Important Considerations

• Duration matters: Short courses (<14 days) are associated with symptom recurrence and return healthcare visits 2
• Tapering: Important to prevent rebound dermatitis
• Contraindications: Consider patient's medical history (diabetes, hypertension, glaucoma, etc.)
• Timing: Start treatment as soon as possible after exposure for best results
• Adjunctive treatments:
  • Washing exposed area with soap and water immediately after exposure (removes up to 100% of oils if done immediately) 3
  • Cool compresses for symptomatic relief 3
  • Oatmeal baths may provide relief 3

Common Pitfalls to Avoid

1. Insufficient duration: Prescribing too short a course (less than 14 days) is a common error that leads to symptom recurrence and return visits 2
2. Inadequate initial dose: Starting with too low a dose for severe cases
3. Abrupt discontinuation: Stopping prednisone suddenly rather than tapering
4. Overlooking contraindications: Not considering patient-specific factors that might contraindicate systemic corticosteroids
5. Delayed treatment: Waiting too long to initiate systemic therapy for severe cases

The FDA label for prednisone emphasizes that dosage requirements are variable and must be individualized based on the disease being treated and patient response 4, but for poison ivy specifically, the evidence supports the dosing regimen outlined above.