Despite how it may look or feel when you’re afflicted with it, poison oak rash is not a disease, and is therefore not contagious. It’s a common misconception worldwide that rashes from poisonous plants, such as poison oak, act like a disease when they spread. The rash from poison oak is actually contact dermatitis caused by an immune system defense reaction when, after contact exposure, the immune system prepares the body for future exposure.
Poison oak sap contains an oily liquid called urushiol that causes an allergic reaction in many people. After exposure to a reactive substance like urushiol, several symptoms typically appear, including itchy red streaks, patches, or both, swelling, and fluid-filled blisters.
The reaction can become noticeable immediately, within just a few hours or much later — as many as five days. As a result, a lot of people incorrectly believe that scratching the poison oak rash and blisters when they first appear causes the “spread” of the rash to other areas. But as long as the sap has been cleaned off the skin so it can’t be absorbed into untouched areas, any new reactions are simply the result of those sections of skin taking longer to react. The fluid in blisters is entirely non-contagious and does not contain any of the oily urushiol.
Although people can’t spread poison oak rash as a disease, the oily urushiol that causes the rash reaction can be spread, even days after coming in contact. In fact, anything that poison oak sap comes in contact with can result in new exposures and reactions. For example, if someone touched poison oak while gardening, the sap might have also contaminated the garden gloves, tools, and clothing. If someone takes a pet for a walk, its fur might also be contaminated.
Doctors recommend that any surfaces excluding the skin that come in contact with poison oak should immediately be cleaned with hot, soapy water. Because the skin has pores that will open and absorb more of the urushiol if exposed to hot water, skin should always be cleansed with soap and cool water that will help close the pores. If a person is away from running water, a stream or lake will work just as well to remove the sap from your skin.
Get to know what poisonous plants look like in all seasons before heading out into the woods and you can save yourself a lot of pain and healing time. If you think you have come into contact with a poisonous plant, the best thing to do is try to wash your skin as soon as possible, and if possible, get everything you’re wearing into a washing machine on hot to avoid potentially exposing yourself all over again!
Images via blmurch, Google Images