Treatment of Severe Poison Ivy: A Randomized, Controlled Trial of Long Versus Short Course Oral Prednisone

BACKGROUND Toxidendron (poison ivy, oak, and sumac) contact dermatitis is a common complaint in the outpatient primary care setting with little evidence-based guidance on best treatment duration. METHODS This randomized, controlled trial examined the efficacy and side effects of a 5-day regimen of 40 mg oral prednisone daily (short course) compared to the same 5-day regimen followed by a prednisone taper of 30 mg daily for 2 days, 20 mg daily for 2 days, 10 mg daily for 2 days, and 5 mg daily for 4 days over a total of 15 days (long course) in patients with severe poison ivy dermatitis. RESULTS In 49 patients with severe poison ivy, non-adherence rates, rash return, medication side effects, and time to improvement and complete healing of the rash were not significantly different between the two groups. Patients receiving the long course regimen were significantly less likely to utilize other medications (22.7% vs. 55.6%, P = 0.02, number needed to treat 3.05). CONCLUSIONS This study suggests that a longer course prescription may save patients' time and exposure to excess medication in the treatment of severe poison ivy. Application of this information to clinical practice will save return visits and reduce excess non-prescription medication administration to individual patients.