Identify, prevent and treat
You’re a landscape maintenance worker who often
works in wooded areas or among weeds or tall brush. You generally wear a
long-sleeved shirt, long pants, socks, sturdy boots or shoes and gloves,
but on this particular day it’s extremely hot, so you wear a
short-sleeved shirt to work and leave the gloves in your truck.
A day or two later, an itchy rash breaks out on part
of your arm. A similar rash that starts as small, red bumps subsequently
appears on your hand. You try to ignore it, but after awhile blisters
develop and the rashes begin to ooze.
It’s very likely that you came into contact with
a poisonous plant. Exposure to the oil found in plants such as poison ivy,
poison oak and poison sumac can not only be annoying, but in some cases,
may be much more serious. Exposure to wild parsnip can result in large
blisters that leave scars lasting as long as two years.
“Knowing what these plants look
like—identification—is key,” says Thao Le, marketing
director for Hyland’s (www.ivyblock.com), a company that develops and markets homeopathic products,
including a product that helps prevent poison ivy, oak and sumac rashes
before they start. Prevention, she adds, is also critical. “Most
people believe that wearing protective clothing is sufficient, but that is
not true. The oils can stay on your tools or clothes. Wearing protective
clothing is not enough.”
How do you identify a poisonous plant? Numerous
resources are available, including the cooperative extension service in
your area, various Web sites and your state department of natural
resources. One good resource is www.emedicinehealth.com, a first aid and consumer health information Web site
written by physicians. This Web site describes poison ivy, poison oak and
poison sumac as follows:
- Poison ivy—Generally found east of the Rocky Mountains. The
plant grows as vines or shrubs, with leaves that have either smooth or
notched edges, often clustered in groups of three, but may also be arranged
in groups of five or seven.
- Poison oak—Commonly grows west of the Rockies. Usually grows as
a small bush, but sometimes as a climbing vine. The leaves have smooth
edges and cluster in groups of three, five or seven.
- Poison sumac—The leaves are generally oval-shaped and smooth, and
have seven to 13 leaves on each stem. Poison sumac is less widespread than
poison ivy and poison oak, but it does grow in certain parts of the
country, including wet areas of the Southeast and in the Midwest.
|Photo by Piotr Jedrzejuk, www.Piotrpix.Com.
||Photo by Robert H. Mohlenbrock, Usda-Nrcs.
|Poison ivy leaves.
||Poison sumac leaves.
The appearance of these plants varies from region to
region and with the seasons.
In some parts of the country, including the Midwest
and New England, landscape workers may also come into contact with wild
parsnip, which is commonly found along roadsides, in poorly maintained
prairies or bordering farmed fields. Wild parsnip grows to be 4 to 5 feet
tall. When in bloom during the summer months, it has many large flat
clusters of yellow flowers on a single, thick stem.
Here is some additional information about poisonous
- The poisonous substance from poison ivy, poison
oak and poison sumac is called urushiol oil. The oil is found in all parts
of the plants, including the leaves, roots and stems. You can become
exposed to the oil not only through skin contact with the plant, but also
by touching clothing, tools, equipment or pets that have been in contact
with the oil from one of these plants. Urushiol oil can stay active on
surfaces, including dead plants, for several years.
- It’s important not to burn these plants
because you can inhale urushiol oil from the smoke of burning plants and
wind up with serious lung irritation.
- Exposure to the urushiol oil in poison ivy,
poison oak or poison sumac causes an itchy rash that usually appears within
24 to 48 hours. In some cases, it may not appear for a few days. The rash
generally starts out as small red bumps, and then later develops into
blisters. Different areas of the skin may break out at different times.
- People who are highly sensitive to poisonous
plants may have an anaphylactic reaction. Among the symptoms are swelling
of the face and throat, difficulty breathing, dizziness or even loss of
consciousness. If any of these symptoms are present, seek professional
emergency medical assistance immediately. Also, if you know you are highly
allergic to these plants, carry an EpiPen (an auto-injector that
- If your skin comes into contact with wild
parsnip’s poisonous sap and is then exposed to sunlight, a rash will
generally appear one to two days later. Symptoms range from slightly
reddened skin to large blisters, which may feel like a mild to severe
sunburn. The blisters do not itch, but leave brown scars that last for
several months to two years.
Prevention and treatment
Be on the lookout for poisonous plants in your area.
Since it might be difficult to completely avoid them when mowing or
performing other tasks, take the following steps:
- Dress appropriately. Wear a long-sleeved shirt,
long pants, gloves, sturdy shoes or boots and socks.
- If you are working in an area with poisonous
plants, thoroughly wash any clothing that may have come into contact with
them at the end of each day. Be careful not to touch the clothing with your
- Remember that your shoes, tools and equipment
can also retain the poisonous urushiol oil for some time. Clean them off
with water and rubbing alcohol. Wear gloves, then discard the gloves when
you are done.
- If you are in an area where wild parsnip grows,
work in the early evening as much as possible to minimize sunlight and
activation of the blistering process should you be exposed to the
plant’s sap. See a doctor if a burning sensation develops.
- Take quick action if you know you have been
exposed to a poisonous plant. In the case of poison ivy, poison oak and
poison sumac, the first 10 minutes are critical, Le notes. If possible,
clean the exposed skin with rubbing alcohol, then wash it with water. Doing
this may not stop the outbreak of the rash if more than 10 minutes have
gone by, but it can help prevent further spread. Remember not to touch the
affected parts of your skin with your bare hands.
- Promptly seek professional emergency medical
help if you have a severe reaction to a poisonous plant.
Barbara Mulhern is a Belleville, Wis.-based
agricultural/horticultural freelance writer.