I get such a severe allergy to poison ivy that once I have it it spreads all through my body without me even having to scratch at it to spread the oil. It makes no sense to me, but my doctor has told me before that I get poison ivy into my blood stream and that is why it spreads so quickly around my body.
Other than my bizarre reaction to being practically covered, I do have some symptoms that are like that of every other normal person! The first being that I typically get it on my fingers (from picking weeds) or on my foot/ankle (walking near it with flip flops or the dog steping on my foot after walking in it).
One tip to preventing getting poison ivy in the first place is to wear long pants and shoes. Another is to wear gardening gloves while weeding. In my case, wearing gloves doesn't help because I just touch other parts of my body with the gloves anyway! The only thing that would work for me is a haz-mat suit!
There are products designed to help block away the poison ivy oils before you make contact. I have not yet tried this because my new motto of just avoiding the poison ivy has worked so far this season.
My better experience is what you do AFTER you have the poison ivy! The best product I have ever used is the Tecnu Extreme Medicated Poison Ivy Scrub!!! I will forever swear by this product...and there are tons of products available to help people with poison ivy. This scrub has slight grit to it so it "scratches" your poison ivy without you having to use your finger nails and open up the blisters. The scrub also has some time of minty/menthol cooling tingling feeling that helps the feeling of itching at bay better than anything else.
Don't be surprised that the price tag for this puppy will start at $15. It doesn't take much when you use it (even when most of your body is infected like mine). I will take up to 3 showers a day just to use this stuff because it makes me feel so much better. My tube has been around for now its 4th summer season and it is still just as effective and active.
I take one additional measure to ensure my comfort during such and unenjoyable experience..and that is using Aveeno Extreme Itch with hydrocortisone.
I have never found calimine lotion to be helpful with poison ivy...but hey, if you get it mildly and it works by all means, turn pepto-bismol pink!
My best bit of advice other than what products to use is to avoid shaving if the poison ivy is in the area you would shave. I think that before I became wise to this concept I caused the poison ivy to spread further because of shaving. If you have it on your left ankle, before you know it you have it in your armpits, your right leg and any other place you shaved.
Sometimes these over the counter products just aren't enough. Most years I have to go to the doctor and get both an oral steroid as well as a cortisone injection (and it is most conveniently administered in your rear).
You should seek medical assistance with this condition if the poison ivy is on or near your eyes and mouth or covering a large percentage of your body.
Do you have poison ivy near you? I found this map from the US Department of Agriculture of the US that helps pinpoint where poison ivy is native and present.