How You "Catch" Poison Ivy

Poison ivy has an oil in it called urushiol. This oil is what causes the allergic reaction and irritation. A person MUST come in contact with the oil in some fashion in order to cause a reaction. This can happen in several ways:

Either: Through direct contact with the plant or plant parts.
This involves touching leaves, stems, vines, berries, or roots, or by being hit by plant pieces being spread around by a lawnmower or weed whacker.

Or:

Touching someone or something that has the oil on them or it.
This could be gardening tools, a pet that has walked through it, a person who has not washed the oil off of themselves, clothing that brushed into it, a ball that rolled into it, camping equipment that was set in it, wood that had a vine on it, etc.

Or:

By inhaling the airborne oil.
If someone burns poison ivy plants or vines, the oil can become airborne and inhaled. That can cause very serious problems. There have also been reports of oil becoming airborne during mowing, although the greater danger is being hit by pieces of it thrown by a mower.
Lightly brushing up against one tiny piece of this plant for a fraction of a second could spell big trouble later.

Note that "walking by the plant" or "being in the same area as poison ivy" does not appear in this list. That's just one of many myths about poison ivy. The oil doesn't magically jump off the plant and get on to you. You have to come in contact with it in, either through direct contact or by inhalation, as mentioned above. I have friends that swear up and down that they can just look at poison ivy and get a rash (my mom also thinks this is how she's gotten it before). That's not possible. More than likely they brushed up against it, touched something that touched a plant, or they petted a cat or dog that got into it.

All parts of the poison ivy plant can cause problems because the urushiol oil is present in the entire plant including the leaves, stems, roots, berries, and vines. The oil is present in live plants, dead plants, and in dormant plants, like the vines, branches and roots in winter. This means do not touch anything at any time.

Another important thing to note is that you need a very small amount of oil to get the rash - specifically, one nanogram, which is one billionth of a gram. That's less than the amount that would fit on the head of a pin. In fact, 500 people could get the rash from the amount covering the head of a pin. So, you don't have to roll around in the stuff to get the rash... just lightly brush the tip of one little leaf and you've got a problem.

Once you've come in contact with the oil, the oil will bind to your skin within 10 to 20 minutes. It can take anywhere from 12 hours to 7 days to see a reaction, but most people react within 24-48 hours. Reactions start off as an itchy red spot which turns into a rash with blisters that weep and ooze. They usually itch like crazy. If this happens, congratulations... you've "caught" poison ivy!

The rash can last anywhere from a few days to several weeks, depending on the severity of your reaction and the treatment methods you choose. If you have a serious reaction such as difficulty breathing, your eyes swell shut, or you break out in hives, seek medical attention right away. Medical professionals also advise seeking help if you have gotten it in your mouth, eyes, mucous membranes, or private areas (watch what leaves you're using for toilet paper!)

You can possibly prevent a reaction if you get the oil off quickly. The best way to not catch poison ivy is to learn to identify it and avoid it.

Not everyone is allergic to poison ivy, but it's better to be safe than sorry. Sometimes immunity can change over the course of a person's lifetime, so you might not be allergic now, but could be later!

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