A rash caused by poison ivy, oak, or sumac may itch and produce blisters. Try the following suggestions and medicines to help relieve these symptoms.

General suggestions

• Although the rash does not spread through blister fluid, try not to scratch blisters. Scratching may cause a bacterial infection to develop.
• Apply wet compresses or soak the area in cool water for 15 to 30 minutes several times a day. Do this for 1 to 4 days until the itching and blistering improve. Compresses or soaking water may include:
  • Baking soda. Add baking soda water to make a solution for a wet compress or mix it with water into a paste and then apply the paste to the rash.
  • Vinegar mixed with water.
  • Burow's solution (aluminum acetate). Apply as a compress during the blistering stage. Caution: Stop using if any irritation develops.
• Take short, cool baths with or without an oatmeal additive (such as Aveeno).
• Wear cotton or silk clothing. Avoid wearing wool and acrylic fabrics next to your skin.
• Use as little soap as possible. Use gentle soaps, such as Basis, Cetaphil, Dove, or Oil of Olay. Avoid deodorant soaps when you have the rash.
• Avoid dry skin, which makes the itching caused by the rash worse. Apply a moisturizer or calamine lotion to the skin while it is damp. Watch closely for excessive drying, which may occur when calamine lotion is used for an extended period. For more information, see the topic Dry Skin and Itching.

Medicine

Medicines that relieve itching include:

• Over-the-counter antihistamine pills or tablets such as Benadryl (diphenhydramine hydrochloride) and prescription antihistamine pills such as Vistaril (hydroxyzine). These medicines may cause drowsiness. Talk to your doctor before using these medicines, and do not drive while taking them. The form of Benadryl you spread on your skin may cause another allergic reaction and should not be used.
• Over-the-counter hydrocortisone products, such as Cortaid, Caldecort, or Lanacort (0.25% to 0.5% active ingredient), that you spread on your skin. These products should only be used in mild cases, usually after the affected area has been soaked in water or a compress has been applied. Although safe, these products are not recommended for treating poison ivy, oak, or sumac rash because they are not strong enough and may not be used long enough to be effective. They may appear to work for a time, but the rash often suddenly flares up again, sometimes worse than before.

Medicines that dry out oozing blisters include:

• Aluminum hydroxide gel.
• Kaolin.
• Zinc acetate, zinc carbonate, or zinc oxide.

If you have a severe rash from poison ivy, oak, or sumac, consult your health professional. You may need prescription corticosteroids.

Do NOT use the following medicines. They may increase sensitization and/or cause more skin problems:

• Antihistamines applied to the skin (such as Benadryl cream, spray, or gel; Dermamycin). The oral form of Benadryl may be helpful.
• Anesthetics containing benzocaine (such as Americaine, Anacaine, Lanacane, Bicozene) that are applied to the skin