- You can spread poison ivy to someone else by contaminating objects with the allergen urushiol.
- Urushiol is an oil that stays on skin for around 30 minutes and on certain surfaces for up to 5 years.
- You probably won't get a rash if you touch someone else's poison ivy blisters.
Poison ivy is not considered contagious in the same sense as an infectious disease.
However, you can get a poison ivy rash by touching someone who has just touched the plant or if you happen to come into contact with contaminated objects like gardening tools or gloves.
Is poison ivy contagious?
A poison ivy rash is medically referred to as contact dermatitis because you only get it if you come in contact with the allergen urushiol, says Christopher Bunick, MD, a dermatologist at Yale Medicine.
Urushiol is the oily substance in the leaves, stems, and roots of the poison ivy plant. Approximately 90% of people are allergic to this substance and develop a rash upon contact.
So, if someone comes in contact with you, in particular, the blisters or fluid on your skin, they probably won't get a rash unless there is still urushiol at the site. Urushiol can remain on your skin for approximately 30 minutes and on other surfaces for up to five years. Therefore, it's possible for someone to get a rash if they use contaminated gardening equipment months or years later.
Here's how certain scenarios can affect your chances of getting or spreading a poison ivy rash:
- Being outdoors in winter: While you may be able to identify poison ivy and steer clear of it in summer, the plant sheds its leaves in winter, leaving behind only brown-colored vines and roots that are harder to identify but still contain urushiol. Therefore, you can get a poison ivy rash year-round, even in winter if you touch the plant without realizing what it is, says Bunick.
- Swimming in a pool: If you have a poison ivy rash, swimming in a pool could give you some relief from the itching. You're not likely to get the rash or spread it to someone else in the pool because the pool water breaks down the urushiol oil.
- Killing the poison ivy plant: Killing the poison ivy plant doesn't neutralize the urushiol, says Bunick. It can stay contagious on dead plants for up to five years.
- Burning the poison ivy: "Urushiol can become airborne if it is burned in a fire. In these cases, the allergen could spread through the air. So if you are camping, don't throw poison ivy into the bonfire," says Bunick. Airborne urushiol is dangerous because it can cause lung irritation, breathing problems, and/or a rash in your mouth, throat, and nasal passages.
Poison ivy rash
A poison ivy rash can appear within a few hours or several days upon contact with urushiol. The rash typically looks like red or black bumps on the skin, although some people may have streaks as well.
In addition to the rash, other symptoms can include:
- Intense itching
- Burning
- Swelling
- Blisters with clear fluid
- Difficulty breathing, if you have inhaled airborne urushiol
It's worth noting that other plants like poison oak and poison sumac also contain urushiol, so coming in contact with them can cause the same rash and similar symptoms, says Bunick.
The phrase "Leaves of three, let them be," came about because poison ivy and poison oak are vines or small shrubs with clusters of three leaves. Poison sumac on the other hand is a tall shrub or a small tree with clusters of seven to 13 leaves. These plants sometimes have small berries on them and their leaves change color with the seasons.
How to get rid of poison ivy
Applying a prescription steroid cream like betamethasone or clobetasol to your skin can clear up most minor cases of poison ivy rash, says Bunick. He says you can use calamine lotion along with the steroid cream, to relieve the itching.
However, Bunick says your doctor may prescribe oral steroid medication for five to seven days if:
- The rash is on your face or on several parts of your body
- The itching is unbearable
If you are unable to take oral steroid medication — or if you require a higher dose — your doctor may administer a steroid shot to help the rash heal faster.
"Most poison ivy rashes last seven to 14 days, with some severe cases going a week or two beyond that," says Bunick.
Insider's takeaway
If you've touched a poison ivy plant, or suspect you've come in contact with urushiol, it's important to wash yourself — and any other materials that came into contact with it — with soap immediately.
The sooner you wash urushiol off the better, since it can reduce the amount of oil your skin absorbs thereby lowering your chances of getting the rash or, at the very least, decreasing its severity. Also, avoid touching anyone or anything else until you've taken a shower.
Getting rid of the urushiol helps prevent others around you from developing the rash as well. "If there is no urushiol present, there is no spread," says Bunick.
