Poison ivy, poison oak becoming stronger over time - updated 6/11/2015

I found poison ivy in my yard last year for the first time.

See the link below for a video on how to identify the plants.

http://www.cbsnews.com/news/poison-ivy-poison-oak-becoming-stronger-over-time/

ByBianca SeidmanCBS NewsJune 9, 2015

Poison ivy, poison oak and poison sumac plants are becoming larger and stronger, a trend that's been developing over recent years, according to researchers. That may be a combination of the plant's nature to cause more severe reactions over time and the increased carbon dioxide in the atmosphere as a result of global warming.

A substance in the plants called urushiol oil is to blame for the notorious itchy rash that develops in people who touch it. According to the U.S. Forest Service, 70 to 85 percent of people exposed to urushiol oil in poison ivy and its cousins will experience an allergic reaction. Unlike other allergies that people may outgrow, sensitivity to this oil gets worse with each additional exposure.

Though urushiol oil starts penetrating the skin immediately, people may not recognize the danger and may continue touching the plant and spreading the oil, since the allergic rash often doesn't appear for 12 to 24 hours.

The first step in prevention is to recognize the poisonous plants, which have distinctive qualities. Many varieties of poison ivy and poison oak have branches with three leaves, hence the popular phrase, "leaves of three, let them be." But the rule isn't foolproof: the leaves sometimes grow in larger clusters. Poison sumac may have clusters of 7 to 13 leaves. The leaves often have black spots which look like paint splatters, caused by blobs of oil that leak out become oxidized in the air and turn black.

Poison ivy grows in every one of the lower 48 states except California, and the Natural Resources Defense Council says it's growing faster and becoming more toxic as a result of warming temperatures.

According to the Centers for Disease Control and Prevention, the best protection is to avoid contact with the plants; don't try to remove or burn them because the oil can cause lung irritation if inhaled.

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There is also a barrier lotion called IvyBlock that contains the only FDA-approved drug to prevent rash from poison ivy, poison oak and poison sumac, known as bentoquatam.

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A more rare and dangerous poisonous plant which is also found in the Northeast, called wild parsnip, can cause rashes that leave scarring and blindness if its oil comes in contact with eyes.

If the oil from a poison ivy, poison oak, poison sumac or related plants touches the skin, remove the oil as quickly as possible to minimize harm. The U.S. Forest Service recommends cleaning the skin with isopropyl (rubbing) alcohol within 10 minutes. Some experts warn that using soap can can actually lift the urushiol oil and spread it around the skin.

Also wash clothes, shoes, gardening tools, even pets -- anything that could have come in contact with the plants or their oils. The oil can remain active on surfaces and cause allergic reactions even years later.

Calamine lotion, antihistamine creams and hydrocortisone can help relieve itching if a rash develops. If a large rash spreads over 10 percent or more of the body, see a doctor.


http://www.cbsnews.com/news/poisonous-plants-like-wild-parsnip-could-spoil-your-summer/

Poisonous plants like wild parsnip could spoil your summer

ByRyan JaslowCBS NewsJuly 13, 2013


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One Iowa man is warning about the wild parsnip, a poisonous plant that's looks like wildflowers, dill or Queen Anne's Lace. When Jack Boyt's son got in contact with the plant while mowing, his arms were covered in burns, blisters and welts.

"It was bad, worse than anything he's ever had," Boyt told CBS News.

Wild parsnip originated in Europe where its roots were eaten, according to Iowa State University. It flowers mostly from May through July.

The plant contains a substance called psoralen that when touched and subsequently put under sunlight, could cause a reaction known as "phytophotodermatitis."

That can lead to reddening of the skin, a rash, and blisters, burning and scalding pain.

Dark red or brownish skin discoloration appears where the burn or blisters first formed, and can last for several months.

"At least warn people, but at best, start to get rid of this stuff," said Boyt.

While poison ivy, poison oak and poison sumac are the most common offenders when it comes to poisonous plants, health officials in states like Maryland have recently been warning against the lesser-known giant hogweed. A dangerous, invasive weed, at present it grows in states including New York, Pennsylvania, Oregon and Washington.

It's part of the carrot family but can grow over 14 feet long, according to the N.Y. Department of Environmental Conservation. The plant's sap contains toxins that, like the parsnip, can cause a skin reaction that's extremely sensitive to light. A blister may form within 48 hours and cause scarring that can last from few months to several years. If the sap gets into your eye, it can cause blindness.

If you come in contact with the plant, get out of the sunlight immediately and wash exposed area with cold water. Apply sunscreen to the affected areas could also prevent further reactions.

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If you come in contact with poison ivy, oak or sumac, immeidatley rinse your skin with rubbing alcohol or dishwashing soap, and use lots of water. Wet compresses can reduce itching or blistering. So too, may oatmeal baths or an antihistamine.

The CDC has more information on poisonous plants.