Found this from the University of indiana, hope it helps, Tim.
Poison Ivy
Poison ivy is the common name given to a plant which can cause an unpleasant, itchy rash (as you probably already know). Here are some facts about the plant and the rash that might help you work and play outdoors more comfortably.
What is poison ivy and how can I identify it?
The plant is extremely common in Bloomington and in the country surrounding the city. It is a versatile plant, and usually grows as a vine on trees, rock walls, or buildings. If there is no such support nearby, poison ivy will grow as a small bush or shrub. Poison ivy has a number of relatives which can cause an identical rash on sensitive persons. This group includes poison oak, poison sumac (which doesn't grow here), the cashew tree, the mango (mango fruit, not the green pepper), and the fruit of the Ginkgo tree.
A typical poison ivy leaf is made up of three leaflets, all joined together to a common stalk. The leaflet stems at the point where they join are often colored slightly reddish (but not always). The leaflets may have toothed edges (as in poison oak) or may be smooth. Grape-like clumps of greenish, then white berries appear in mid-summer, and in fall the leaves turn an attractive orange-yellow or red.
How does poison ivy cause a rash?
The rash occurs after a person who is allergic to poison ivy gets the sap from the plant on the skin. The plant must be damaged (bruised or cut) before the sap can escape, so touching an undamaged plant will usually not cause a rash. Damaging any part of the plant (including the vine and roots), any time of year will release enough sap to cause problems. Smoke from burning the plant can also cause a rash, or worse reactions if it is inhaled. Pets, tools, and clothing can carry the sap to the skin also.
What is the treatment for poison ivy?
Once the sap gets on the skin it soaks in quickly. Washing with soap and cool water within 10 or 20 minutes of exposure may prevent the rash, but washing within an hour of exposure can reduce the seriousness of the rash that follows. After an hour or two the sap soaks in completely and can no longer be released from the skin. The sap can be carried on clothing, shoes, tools and pets for weeks and still cause a rash if touched. Soap and water washing of these items is an important step in getting rid of the sap. The rash appears in one or two days, but may start as early as six hours or as much as two weeks after exposure.
The rash cannot be spread by scratching or by the blister fluid. It usually heals within two or three weeks. Broken blisters can become infected like any other open wound, and should be well cared for. An antibiotic ointment and band aids may be used. The rash will itch and swell more with a hot shower, whirlpool, or sauna, so cool baths or showers will be more comfortable. Over the counter medications such as calamine lotion, Burow's solution soaks and hydrocortisone cream might produce some relief. If you are not able to obtain relief using these suggestions you may want to see a health care provider for further assessment.
Unfortunately, "shots" of poison ivy sap are not of much help in preventing poison ivy. Some "barrier creams" (such as Stokogard) can be effective in preventing or slowing the absorption of the poison ivy sap into the skin, but soap and water washing is still required as soon as practical after exposure. Still, knowledge and avoidance of the plant are the best for prevention.
The Whole Truth About Poison Ivy
The poison ivy rash can't be spread by scratching once the rash has developed.
The sap from the poison ivy plant causes the rash.
Damaging any part of the plant, any time of year releases the sap.
The sap can be carried on tools, clothing, and pets for weeks and still cause a rash if touched.
The sap can soak through cloth or rubber gloves, or clothing.
Smoke from burning the plant contains the sap.
A person can become sensitive to the sap at any time in life.
Soap and cool water washing within 10 to 20 minutes of exposure to the sap can prevent the rash.
Washing an hour or two after exposure to poison ivy can lessen the seriousness of the rash that follows.
The rash usually appears within two days, but can take as little as six hours or as much as two weeks to develop.
The poison ivy plant is extremely common in Bloomington.
Poison ivy "shots" are of NO use in preventing the rash.
Some so-called skin barrier creams or sprays can provide slight protection from the sap (and the rash).
The best protection comes from avoiding the plant!
