Oral desensitization therapy for poison ivy urushiol contact allergy: A systematic review

Summary: Abstract Body: This study evaluates the potential of oral desensitization to mitigate hypersensitivity to poison ivy, a common cause of allergic contact dermatitis. We systematically reviewed prior research on the efficacy of oral exposure to urushiol, poison ivy's allergenic oil, to reduce dermatologic complications. A PRISMA-guided review identified studies from 1959 to 2003, including six human trials with 563 participants and two animal studies. Studies assessed oral administration of urushiol derivatives in liquid or tablet form against placebo or untreated controls. The results showed that oral desensitization reduced hypersensitivity in 44%-94% of participants. Complications were mild, with the most common side effects being vesicular rash, flushing, and pruritus ani, none exceeding typical poison ivy reactions. Quality assessments using the NHLBI tool classified four studies as "good" and four as "fair." While limited by small sample sizes and dated methodologies, these studies highlighted a promising trend of decreased reactivity to poison ivy exposure following oral desensitization. This research highlights the importance of exploring allergen-specific immune modulation, particularly for high-risk populations such as outdoor workers. Although foundational, these findings call for modern clinical trials to validate and expand upon this therapeutic approach, addressing critical gaps in prophylactic measures against poison ivy hypersensitivity. Natasha E. Barton¹, Dakota Hitchcock¹, Parker Juels¹, Olivia Ueltschi², Emily G. Woolhiser³, Elizabeth Lamberty¹, Robert Dellavalle⁴, Cory Dunnick⁵ 1. University of Colorado Anschutz Medical Campus School of Medicine, Aurora, CO, United States. 2. The Ohio State University College of Medicine, Columbus, OH, United States. 3. Kansas City University College of Osteopathic Medicine, Kansas City, MO, United States. 4. Dermatology, University of Minnesota Medical School, Minneapolis, MN, United States. 5. Dermatology, University of Colorado Anschutz Medical Campus School of Medicine, Aurora, CO, United States. Adaptive and Auto-Immunity