Wednesday, May 20, 2009

Toxicity and All

Poisonings and deaths from garden plants are rare as most poisonous plants taste unpleasant. It is important to remember that small children are often at risk from coloured berries, petals and leaves. It doesn't mean every poisonous plant should be removed from the garden. It's best to teach children to NEVER eat seeds, berries or other plant part without asking first.


The potential danger varies depending on dose. Some plants are capable of causing serious illness or death with only a small amount of exposure while others require large quantities be consumed before even mild symptoms occur.


Poisoning from plants may occur from ingesting, inhalation or direct contact.

Symptoms from ingestion include gastroenteritis, diarrhoea, vomiting, nervous symptoms and in serious cases, respiratory and cardiac distress.

Poisoning by inhalation of pollen, dust, or fumes from burning plants can cause symptoms similar to hay fever or asthma.

Contact poisoning on the skin or in the eyes can occur from direct contact with plant sap, fine hairs or burrs; this can result in swelling, rashes or blistering.

Today, I'm going to talk about a plant that every Midwesterner knows about but most of us have contacted anyway: The dreaded Poison Ivy Toxicodendron radicans.

We've been told for years, "At the sign of three (leaves) - run the other way." But, poison ivy can have up to eight leaves and sometimes they look different. They are green in the summer and turn very red in the fall (a good identification).

Approximately 85% of the population will develop skin allergies to poison ivy (or poison oak and sumac.) Sensitivity can develop immediately or it can develop over many years of exposure.

The cause of the rash, blisters, and infamous itch is urushiol (pronounced oo-roo-shee-ohl), a chemical in the sap of poison ivy, oak and sumac plants.

Urushiol that's rubbed off the plants onto other things can remain potent for years, depending on the environment. If the contaminated object is in a dry environment, the potency of the urushiol can last for decades. Even if the environment is warm and moist, the urushiol could still cause a reaction a year later. Think about clothes, shoes, and tools.

Almost all parts of the body are vulnerable to the sticky urushiol, producing the characteristic linear (in a line) rash. Because the urushiol must penetrate the skin to cause a reaction, places where the skin is thick, such as the soles of the feet and the palms of the hands, are less sensitive to the sap than areas where the skin is thinner. The severity of the reaction may also depend on how big a dose of urushiol the person got.

If you've been exposed to poison ivy:

1. Cleanse exposed skin with generous amounts of isopropyl (rubbing) alcohol. (Don't return to the woods or yard the same day. Alcohol removes your skin's protection along with the urushiol and any new contact will cause the urushiol to penetrate twice as fast.)

2. Wash skin with water. (Water temperature does not matter; if you're outside, it's likely only cold water will be available.)

3. Take a regular shower with soap and warm water. Do not use soap before this point because soap will tend to pick up some of the urushiol from the surface of the skin and move it around.

4. Clothes, shoes, tools, and anything else that may have been in contact with the urushiol should be wiped off with alcohol and water. Be sure to wear gloves or otherwise cover your hands while doing this and then discard the hand covering.

The rash:

Redness and swelling will appear in about 12 to 48 hours. Blisters and itching will follow. For those rare people who react after their very first exposure, the rash appears after seven to 10 days.

Because they don't contain urushiol, the oozing blisters are not contagious nor can the fluid cause further spread on the affected person's body. Nevertheless, scratching the blisters because fingernails may carry germs that could cause an infection.

The rash will only occur where urushiol has touched the skin; it doesn't spread throughout the body. However, the rash may seem to spread if it appears over time instead of all at once. This is either because the urushiol is absorbed at different rates in different parts of the body or because of repeated exposure to contaminated objects or urushiol trapped under the fingernails. If the poison is on an exposed open sore or scratch, it may cause other problems.

The rash, blisters and itch normally disappear in 14 to 20 days without any treatment. But few can handle the itch without some relief. For mild cases, wet compresses or soaking in cool water (some add soda) may be effective. Oral antihistamines can also relieve itching.

FDA also considers over-the-counter topical corticosteroids (commonly called hydrocortisones under brand names such as Cortaid and Lanacort) safe and effective for temporary relief of itching associated with poison ivy.
If symptoms are severe: See your doctor. Your doctor may prescribe oral corticosteroids if the rash is on the face, genitals, or covers more than 30 percent of the body. The drug must be taken for at least 14 days, and preferably over a three-week period. Failure to take as prescribed may case the symptoms to rebound even worse.

Covering the body seems to be the only way to help prevent exposure as topical preventatives have not been proven effective.

(Much of the above information was researched from the FDA web site)

Killing the plant:

You're options are poisoning or pulling the weed. The only poisons (Roundup and Ortho Poison Ivy Killer) that effectively kill it all will also kill most anything else it touches. Pulling will potentially cause you to contact the poison. You must get every bit of the plant--leaves, vines, and roots--or it will sprout again. Check out the labels of poisons to see exactly what they will kill - Ortho may not kill trees.

Do not compost (stays active), do not burn (the oil will float on air and the smoke can cause lung problems) , and do not throw on brush piles (it can take root).

I spent years being very sensitive to poison ivy. I take an aggressive approach to killing the plant - Roundup - at the first sight. I am willing to sacrifice anything around it. I don't appear to be as sensitive anymore - either I'm more observant or have built up a tolerance; probably the first.

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