What is poison ivy, oak or sumac?

Poison ivy, poison oak and poison sumac are plants that can cause an itchy skin rash. The rash is caused by urushiol, an oil in the plants.

If you are allergic to any of these plants, you may develop an itchy, blistering rash 12 – 72 hours after contact with the oil.

Poison ivy, oak and sumac rashes typically clear within a few weeks.

Causes of poison ivy, oak and sumac rash

Poison ivy, poison oak and poison sumac all contain urushiol, an oily secretion that causes an allergic reaction on your skin.

This residue can adhere to clothing, tools and skin, spreading on yourself or to others even after coming into contact with poison ivy, oak or sumac.

Risk factors for poison ivy, oak and sumac rash

Poison ivy, poison oak and poison sumac can grow in open fields, wooded areas, backyards and riverbanks, which makes spending time outdoors – for work or play – a considerable risk factor.

Since urushiol must come into contact with your skin in order to cause a reaction, you should cover your skin with clothing, gloves or a topical barrier cream when working in an environment that might contain poison ivy, poison oak or poison sumac.

All clothing and equipment should be washed after being outside in an area that may contain any of these plants.

Symptoms of poison ivy, oak and sumac rash

Symptoms of poison ivy, oak or sumac may take hours, days or a week to appear after exposure.

Signs and symptoms include:

  • Rash
  • Streaks, patches or clusters of redness
  • Swelling
  • Itching
  • Blisters
  • Crusting after the blisters burst

Although you can spread the rash to other parts of your body if you touch the oil and touch a different body part, you cannot spread the rash to another person. That person needs to touch the oil to break out in a rash.

Diagnosis of poison ivy, oak and sumac rash

Poison ivy, oak or sumac rash can be diagnosed by a primary care provider who will examine your skin and discuss possible exposure with you. If you have a serious case, you may be sent to a dermatologist.

If you have any of the following symptoms, visit the emergency room right away:

  • Trouble breathing
  • Rash covering most of your body
  • Rash on genitals or face
  • Severe swelling
  • Eyelid swollen shut

Treatment for poison invy, oak and sumac rash

If you know you’ve been exposed to poison ivy, poison oak or poison sumac, you should immediately cleanse your skin with warm water and mild soap and wash any clothing that may have touched the plants.

This will reduce the severity of a skin reaction and prevent the spread of urushiol.

Symptoms of poison ivy, oak or sumac rash can be treated with:

  • Calamine lotion
  • Antihistamines
  • Cool compress
  • Corticosteroid ointment – over-the-counter or prescription, used to reduce inflammation

Severe reactions to poison ivy, oak or sumac may require prescription medication including:

  • Topical steroid ointment
  • Prednisone
  • Antibiotic (if infection develops)

Recovery from poison ivy, oak or sumac rash

Skin reaction to poison ivy, poison oak or poison sumac can take as long as three weeks to fade. Scratching affected areas of your skin may cause the rash to become infected, which will only intensify itchiness and further delay healing.

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