Picture of poison ivy rash on face Picture of poison oak rash on leg
Image of poison ivy rash on wrist Image of poison oak rash on hand

What Does a Poison Oak or Poison Ivy Rash Look Like?

It's a question we are often asked. Folks that adventure or work in the outdoors may have been exposed to poison ivy or oak and want to know what to expect. Others have broken out and are trying to determine if their rash is from poison ivy, oak or sumac plants.

Picture of blistering poison ivy rash on wrist Picture of poison oak rash on elbow
Image showing poison ivy rash on fingers Poison ivy rash on leg starting to scab over

Before we get into what a poison ivy rash looks like, it is important to cover what exactly causes the rash. Poison oak, ivy, and sumac all contain the same rash-causing allergen, urushiol (pronounced: oo-roo-she-all). Urushiol is a potent substance found in all parts of the plant including the leaves, stem, and even the roots. A little bit of this oil goes a long way; it is incredibly powerful!

Urushiol does not evaporate, and exposure can occur from direct or indirect contact. It can last on items such as tools, clothing, gear, fences, pets, etc. for months, even years. This makes it possible to develop a rash the next time you encounter these items.

Contact with urushiol causes an allergic reaction in about 85% of the American population. The body's natural reaction to the plants causes a rash, swelling and irritation. This condition is called contact dermatitis. Sensitivity to urushiol develops over time and can increase as a person has more contact. It isn't uncommon for an individual to go without a reaction to poison ivy or oak, and then one day develop a rash.

A poison ivy rash can appear anywhere from 24-36 hours after exposure, and last between 2 to 4 weeks. How quickly symptoms appear, and the duration of your rash depends on a few factors:

  • Your sensitivity to urushiol
  • The amount you were exposed to
  • The number of exposures to the substance over your lifetime
Image of poison oak rash on forearms Poison ivy rash on arms starting to heal
Image of poison oak rash in bend of arm Poison ivy rash pictured on legs and hands

Rashes and what they look like vary from person to person. Symptoms can include intense itching, redness, swelling, or blisters. It is important to never break the blisters, as it may cause an infection. The liquid that oozes from the blisters often dries to form a yellow crust-like substance. It's best to leave the rash uncovered to allow oxygen to aid the healing process. However, if the blisters ooze excessively, use a loose bandage to cover the area.

Contrary to popular belief, you cannot "cure" a poison ivy or oak rash. You must let your body run its natural course. However, there are products you can use to help ease your symptoms (itching, redness, inflammation, etc.). Examples are Calagel Anti-itch Gel and Tecnu Rash Relief Spray.

Seek immediate medical attention if:

  • You experience a severe reaction (i.e. swelling of the face, trouble breathing, etc.)
  • Your rash worsens, or
  • Your rash doesn't improve