The blisters break open and releases a watery liquidthe liquid however is not contagious. The rash will only occur where the urushiol has touched the skin, it does not spread throughout the body. The rash may seem to spread because the urushiol could have been absorbed at different rates by the skin, or repeated exposure to contaminated objects like urushiol oil trapped under the fingernails. Urushiol oil can remain potent for one to five years, including on the surface of dead plants. Almost 85 percent of the worlds poulation will develop an allergic reaction if exposed to poison ivy or its relatives. It is the most common allergy in the United States claiming half the population.
There are many ways to treat someone who has come in contact with the plant. If the person knows they have come in contact with the plant then they should put large amounts of isopropyl alcohol on the probable infected skin. Don't return to the woods the same day though because with the alcohol on the skin you can become infected twice as fast. Second you should wash your skin with water, the temperature doesn't matter. Third you should take a shower with soap and warm water, but do not use soap before this point because soap can pick up urushiol oil and move it around. Clothes and shoes that have been infected should be wiped off with alcohol and water. While doing this be sure to wear gloves and then discard the gloves when you are through. Any shoes or clothing that cannot be washed should be well ventilated for at least three weeks to avoid another exposure.
If someone doesn't know that they are infected with the oil until a rash appears then they can get an over the counter medication such as Zanfel or Cortaid. All over the counter medications work but some are just used to relieve itching, not to cure the poison ivy. For mild cases, to relieve itching soak the infected area in cool water or use a cool compress.