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Allergy: Poison Ivy, Oak, and Sumac (cont.)

What Symptoms and Signs Accompany a Poison Ivy, Oak, and Sumac Rash?

  • Exposure to poison ivy, oak, or sumac causes an itching skin rash that usually appears within 24-72 hours.
  • The rash usually starts as small red bumps and later develops blisters of variable size. The rash may crust or ooze. It may look like red, bumpy lines or streaks on the skin.
  • The rash may be found anywhere on the body that has contacted the oil from the plant. It can have any shape or pattern but is often in straight lines or streaks across the skin.
  • Different skin areas can break out at different times, making it seem as if the rash is spreading.
  • Contrary to popular belief, leakage of blister fluid does not spread the rash. It is spread only by additional exposure to the oil, which often lingers on hands, clothing and shoes (which are often overlooked as carriers), or tools.
  • The rash caused by poison ivy, oak, or sumac generally lasts about two to three weeks.
  • While poison ivy, oak, or sumac rash can be persistent, these rashes are not recurrent. The rash does not lie dormant and then reappear in the same spot. If you have a bout of poison ivy, oak or sumac that seems to recur, it's more likely you encountered the plant again, or oil from the plants may not have been completely removed from all clothing or surfaces. You may also have a bacterial or fungal infection in the same spot that requires treatment.

When Should Someone Seek Medical Care for a Poison Ivy, Oak, or Sumac Rash?

See a health-care professional for the following conditions:

  • Large areas of rash causing significant discomfort
  • A rash on the mouth, genitals, or around the eyes
  • An area of the rash that becomes infected or drains pus
  • A great deal of swelling

People who are highly sensitive to these plants can get a severe allergic reaction called anaphylaxis.

  • If someone has swelling of the face and throat or difficulty breathing, feels dizzy or faint, or loses consciousness, he or she may be having an anaphylactic reaction.
  • If someone has any of these symptoms, go immediately to a hospital emergency department.
  • Do not attempt to drive; call 911 for emergency medical treatment.
  • While waiting for the ambulance to come, begin self-treatment measures.
Medically Reviewed by a Doctor on 6/6/2016

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