|I'm allergic to poison and since I rock climb and visit wooded areas often, it's inevitable that I get it so I thought I'd share some information on poison ivy with you.
The best solution I've found is what everyone has recommended, after going into woods or areas where any contact with Poison, Ivy, Oak, or Sumac is possible, go home strip your clothes (yes your shoes to, infamous place to get urushiol, the plant's oil). Wash your clothes, and take a show, taking care to scrub very hard and well with a strong soap or detergent.
If you are unlucky and have not been able to avoid it, try some of the store bought remedies as they might relieve the itching, puss, and swelling. See a doctor if rash becomes severe or persists for a longer period of time than normal, as you may be able to be prescribed stronger treatments and steroids which can help immensely. Mixing baking soda and water to the consistency of corn syrup and applying several times, letting dry for a few hours seems to help the symptoms. Tends to alieve swelling, puss, and itching in 1-2 days for me, but may be different for each individual. Oatmeal baths, have also been known as a home remedy to help with the symptoms as well.
What not to do:
Scratch. The more you scratch the more it will itch usually, as scratching can caused increased bloodflow and increased reaction. It's temporary and the itch will almost immediately return after you stop, which leads to some people scratching till they bleed. Better to suck it up for that first day, and then the itch will *usually* subside in the following days.
Bleach. Never, Ever, EVER, apply bleach. Household Bleach (Sodium hypochlorite) is an extremely powerful and potent oxidizing agent. It kills bacteria, germs, fungi and even some viruses, and WILL burn your skin and can do serious harm.
Pop the blister. This will open up the sterile enviroment and increase chance of infection. Your nails carry bacteria which can easily be transferred into the opened tissue. Scratching also increases chance of urushiol getting on your fingernails and subsequently spreading it to other parts of your body.
Lastly, the symptoms of Poison Ivy CAN be chronic. They might dissappear and reappear. This can be due re-exposure, not getting rid of all the oils, or a few cases where your body's histamine response continues after your symptoms have subsided and may return with stress, and other uknown stimuli.
Cheers! I hope this helps.