Causes:
A poison ivy/oak/sumac reaction is caused by the active ingredient urushiol. This thick, oily substance is present in the resin emitted from the plant's leaves, flowers, fruit, stem, bark, and roots. Once on your skin, the resin binds to skin cells, causes irritation, and produces a rash. Petting a dog or cat that has come into contact with the plant is the second most common means of exposure (the pets themselves are not affected). If the plant is burned and the smoke is inhaled, a serious form of infection can also occur.
Urushiol is considered one of the most powerful toxins on earth. It would take only 1/4 oz. to affect every person on the planet. Highly sensitive individuals need only be exposed to one nanogram (one billionth of a gram) of urushiol to receive a rash. An amount covering the head of a pin could cause itching in five hundred people. Indeed, the resin is potent stuff.
Itching, swelling, and blisters are caused by your immune system's response to the resin.
What to Expect:
If you are allergic to poison ivy resin (and most people are), a rash will develop in all areas of your body that have come in contact with the plant twenty four to forty eight hours after exposure. Intense itching accompanies the rash, as do blisters and oozing caused by blood vessels developing gaps and leaking fluid through the skin. Symptoms peak four to seven days after exposure.
The resin should be removed as soon as possible. The longer it stays in contact with your skin, the more intense and widespread your rash will become. Scratching the rash is the easiest way to spread it.
If you break out in a rash that begins to swell four to twelve hours after exposure, seek medical attention from your naturopath or other health practitioner.
Most people heal within seven to fourteen days.
