Poison Oak Rash

You have a rash and itching. This is a delayed reaction to the oils of the poison oak plant. You likely came in contact with it during the 3 days before your symptoms started. Your skin will become red and itchy. Small blisters may appear. These can break and leak a clear yellow fluid. This fluid is not contagious to others. The reaction usually starts to go away after 1 to 2 weeks. But it may take 4 to 6 weeks to fully clear.

Home care

Follow these guidelines when caring for yourself at home:

  • The plant oils still on your skin or clothes can be spread to other places on your body. They can also be passed on to other people and cause a similar reaction. That’s why it’s important to wash all of the plant oils off your skin and any clothes that may have been exposed. Wash all clothes that you were wearing. Use hot water with regular laundry detergent. Dogs and cats that get into poison ivy may not get a rash, but the plant oils may be on their fur. Be sure to wash your pets, too.

  • Don't use over-the-counter topical antibiotic creams such as neomycin or bacitracin. These may make the rash worse.

  • Avoid anything that heats up your skin. This includes hot showers or baths, or direct sunlight. These can make itching worse.

  • Put a cold compress on areas that are leaking (weeping), or blistered areas. Do this for 30 minutes, 3 times a day. To make a compress, dip a wash cloth in a mixture of 1 pint of cold water and 1 packet of astringent or oatmeal bath powder (colloidal oatmeal, sold in pharmacies). Keep the solution in the refrigerator for future use.

  • If large areas of skin are involved, you may take a lukewarm bath. Add colloidal oatmeal to the water. Or you can add 1 cup of cornstarch or baking soda to the water.

  • For a rash in a smaller area, use hydrocortisone cream for redness and irritation. But don’t use this if another medicine was prescribed. For severe itching, put an ice pack on the area. To make an ice pack, put ice cubes in a plastic bag that seals at the top. Wrap the bag in a clean, thin towel or cloth. Never put ice or an ice pack directly on the skin. Over-the-counter lotions that have calamine may also be helpful.

  • You can also use an oral antihistamine medicine with diphenhydramine for itching, unless another medicine was prescribed. This medicine may make you sleepy. So use lower doses during the daytime and higher doses at bedtime. Don’t use medicine that has diphenhydramine if you have glaucoma. Also don’t use it if you are a man with trouble urinating because of an enlarged prostate. Antihistamines with loratidine cause less drowsiness. They are a good choice for daytime use.

  • For severe cases, your provider may prescribe oral steroids such as prednisone. Always take these exactly as prescribed.

Follow-up care

Follow up with your healthcare provider, or as advised. Call your provider if your rash gets worse or you are not starting to get better after 1 week of treatment.

When to seek medical advice

Call your healthcare provider or seek medical attention right away if any of these occur:

  • Spreading facial rash with swelling of mouth or eyelids

  • Rash that spreads to the groin and causes swelling of the penis, scrotum, or vaginal area

  • Trouble urinating because of swelling in the genital area

Also call your provider if you have signs of infection in the areas of broken blisters:

  • Spreading redness

  • Pus or fluid draining from the blisters

  • Yellow-brown crusts form over the open blisters

  • Fever of 100.4°F (38ºC) or higher, or as directed by your provider

Call 911

Call 911 if you have trouble breathing or swallowing. Or if you have severe swelling in your face, eyelids, mouth, throat, or tongue.

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