If you know you will be working around poison ivy, oak, or sumac, you may think about using a barrier cream or lotion to help prevent the plant oil (urushiol) from contacting your skin and causing a rash (allergic contact dermatitis).

• Less than 1 hour before contact with the plant, apply the product in a thick, complete layer.
• Wash the product off thoroughly within 4 hours (preferably as soon as possible) after contact with the plants. The product only delays the penetration of the urushiol.
• For continued protection, reapply the product every 4 hours.

Products containing 5% bentoquatam (such as Ivy Block) have been shown to be highly effective in preventing the rash and reducing its severity. Products containing bentoquatam should not be used on children younger than age 6 or by anyone who already has a rash from the poison ivy, oak, or sumac plants. These products are available without prescription.

Barrier creams and lotions do not completely protect against developing a poison ivy rash.