Poison oak rash is an allergic reaction to the leaves ... Like poison ivy and poison sumac, poison oak releases an oil called urushiol when it sustains damage. Your skin absorbs this allergen ...

A poison sumac rash is usually accompanied by redness, swelling, blisters, and an intense itch. After you come in contact with poison sumac, you need to clean the area with soap and water.

Medically reviewed by Susan Bard, MD An itchy rash with blisters can be caused by an allergic reaction; an autoimmune ...

Learn how to identify poison ivy, oak, and sumac plants and the rashes they cause ... of Massachusetts Extension Weed Herbarium offers pictures of various parts of the poison ivy plant to help ...