Poison ivy

Many people get a rash from poison ivy, poison oak, and poison sumac. This rash is caused by an oil found in the plants. This oil is called urushiol (you-ROO-shee-all). The itchy, blistering rash often does not start until 12 to 72 hours after you come into contact with the oil.

The rash is not contagious and does not spread. It might seem to spread, but this is a delayed reaction.

Most people see the rash go away in a few weeks. To make the skin feel more comfortable during this time, you’ll find tips from dermatologists here:

• Read these tips for treating and preventing poison ivy.

If you have a serious reaction, you need to see a doctor right away. Swelling is a sign of a serious reaction — especially swelling that makes an eye swell shut or your face to swell.

You should see a doctor if the rash covers a large part of your body, you have large blisters, or cannot sleep.If you have trouble breathing or swallowing, go to an emergency room immediately.

Source: https://www.aad.org

Signs, symptoms

What you see and feel on your skin is caused by urushiol (you-ROO-shee-all). Urushiol is the oil in poison ivy, oak, and sumac. You find this oil in all parts of the plants — the leaves, stems, and even the roots. Within minutes of contact with urushiol, the skin starts to absorb it. But you don't feel this. And you don't see a rash right way.

If this is your first contact with urushiol, you may not see a rash. Or it may take a week for the rash to appear. The rash also can appear within hours or a few days. If you have a reaction to the oil, you can have these signs (what you see) and symptoms (what you feel):

• Itchy skin.
• Redness or red streaks.
• Hives.
• Swelling.
• An outbreak of small or large blisters, often forming streaks or lines.
• Crusting skin (after blisters burst).

The rash is very itchy and can appear on any part of the body. The rash can continue to appear on new parts of the body when:

• Other parts of the body touch the oil.
• You spread the oil on your skin by touching other parts of your body.

You cannot give the rash to someone else. Even if the person touches the rash or the fluids in the blisters, the person cannot get the rash. The person has to touch the oil to get the rash.

Source: https://www.aad.org

Who gets, causes

Who gets this rash?

Most people (85 percent) develop a rash when they get urushiol on their skin. The first time you get this oil on your skin, you may not get a rash. The next time this oil gets on your skin you can become sensitive to it. Once you are sensitive to it, a rash appears. About 15 percent of people do not become sensitive to this oil and never develop a rash.

Adults who had rashes as a child often find that they are less sensitive as adults. They may completely lose their sensitivity and never get another rash when the oil touches their skin. Adults who never had a rash as a child may become sensitive to the oil.

What causes this rash?

There are 3 ways to get this rash:

1. Direct contact
   By touching poison ivy, poison oak, or poison sumac, you can get a rash. Every part of these plants — the leaves, stems, roots, and flowers — contains the oil.
2. Indirect contact
   Urushiol can stick to almost anything. If you touch a pet's fur, gardening tool, or sports equipment that has the oil on it, you can get a rash. Dogs and other animals do not get this rash. Only people get this rash.
3. Airborne contact
   Burning these poisonous plants releases particles of urushiol into the air. These airborne particles can land on the skin.

It is not possible to get this rash from touching someone who has the rash. The skin absorbs the oil too quickly. You cannot get a rash from getting the fluid in the blisters on your skin.

Source: https://www.aad.org