10 Common Allergy Triggers Slideshow Pictures Take the Quiz on Allergies Nasal Allergy Relief Slideshow Pictures

Medical Author:

Daniel Jobe, MD

Coauthor:

Zoe Diana Draelos, MD, PA

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

Causes of Poison Ivy, Oak, and Sumac Rash

The rash caused by poison ivy, oak, and sumac is an allergic skin reaction to an oil, called urushiol, which is in the plant. This oil is found in all parts of the plant, including the leaves, stems, roots, and berries.

• Exposure to the oil occurs through any of the following:

• Touching any part of the plants

• Touching clothing or other objects that have contacted the plants

• Touching pets or other animals that have contacted the plants

• Exposure to the smoke of burning plants

• For more information about how these reactions occur, see Allergic Reactions and Contact Dermatitis.