What Is
POISON IVY?
Poison
ivy is a very common plant found in most parts of the United States. It has
two forms. One form is a low plant. It is usually found in groups of many
plants and looks like weeds growing from 6 to 30 inches high. The other form
is a "hairy" vine that grows up a tree. Each form has stems with 3 leaves.
You may have heard the old saying, "Leaflets three, let it be." This is
because most people are allergic to poison ivy.
How does poison ivy cause a rash?
The poison ivy plant contains an oil called urushiol (say:
oo-roo-shee-ohl). Most people are allergic to urushiol. If you are
allergic to it and you get it on your skin, you'll develop an itchy, red
rash. You can get the oil on your skin by:
- touching the poison ivy plant
- touching any clothing,
including shoes, that have come in contact with the plant.
- touching any gardening tools
that may have the oil on it.
- touching any outdoor pets
that have been around poison ivy and have gotten the oil on their hair.
- burning the poison ivy plant.
The oil from the plant is carried in the smoke.
What is a poison ivy rash like?
A poison ivy rash will usually begin to appear 1 to 2
days after coming in contact with urushiol. The affected area will get red
and swollen. A day or so later, small blisters will begin to form, and the
rash will become very itchy. During this time, it's important to try to keep
from scratching the blisters. Bacteria from under your fingernails can get
into the blisters and cause an infection. After about a week, the blisters
will start to dry up and the rash will start to go away. In severe cases,
where the poison ivy rash covers large parts of the body, it may last much
longer.
How is poison ivy treated?
If you think that you've come in contact with the poison ivy plant, you
need to wash your skin as soon as possible. You should use soap and cool
water. This may help to get some of the urushiol off your skin.
Once a rash starts to develop, there are several over-the-counter
medications you can use to relieve the itching, including:
- hydrocortisone creams (brand
name: Cortizone-10)
- calamine lotion
- Antihistamine tablets, such
as diphenhydramine (one brand name: Benadryl)
- oatmeal baths
You should call your doctor if:
- you have fever over 100
degrees
- the rash covers large areas
of your body
- the rash is in your eyes or
mouth or on your genital area
- there is pus coming from the
blisters
- the rash does not get better
after a few days
Created: 06/05
This handout provides a
general overview on this topic and may not apply to everyone. To find out if
this handout applies to you and to get more information on this subject,
talk to your family doctor.
Copyright ? 2005 American
Academy of Family Physicians
Permission is granted to print and photocopy this material for nonprofit
educational uses.
