5 Fast Facts About Poison Ivy, Poison Oak and Poison Sumac

Poison ivy, poison oak and poison sumac are plants that contain an oil called urushiol, which causes the characteristic red, raised, blistering, intensely itchy rash. Here are five fast facts about this common condition.

1. The Rash Doesn’t Show Up Right Away.

When you come into contact with one of these plants, you often won’t notice any difference in your skin for at least a day. The rash typically appears 24-72 hours after exposure.

2. Not Everyone is Allergic to These Plants.

The degree of the reaction you have to these plants (or whether you have a reaction at all) varies from person to person, depending on how sensitive your immune system is to the urushiol oil. People who are highly allergic to urushiol release higher amounts of histamine, creating a more severe reaction. People who aren’t sensitive to urushiol (about 15% of the population) may be exposed to the oil and have no reaction at all.

3. Clothing is the First Line of Defense.

Since these plants are ubiquitous across North America, it’s hard to avoid coming into contact with them when you’re camping, hiking, gardening or enjoying other outdoor activities. So the first line of defense is to cover as much skin as possible. By wearing long sleeve shirts and long pants, and wearing gardening gloves when you’re working outdoors, you can prevent the plants from coming into contact with your skin.

4. The Rash is Not Contagious.

In order to develop the allergic rash, you have to come into contact with the plant itself, which means that the poison ivy/oak/sumac rash isn’t contagious from person to person, even if you come in contact with the fluid inside the blisters.

5. Medications Can Clear the Rash Up Faster.

There are several classes of effective medications that can alleviate uncomfortable symptoms and help the rash resolve faster, including antihistamines, steroids and topical creams. If you develop a poison ivy/oak/sumac rash, especially if it covers a large area of skin or affects your face or genitals, it’s wise to see a medical provider as soon as possible to determine which medication is right for you.