The first thing to do if you know you've incountered Ivy is to wash yourself off with the coldest water you can stand. No soap, just ice cold water, don't rub. Remove cloths and tub soak in ice cold water, no soap before you machine wash them.
The sap in the ivy is made up of a crystal and the ice cold water breakes down the structure. You have to do this within 20 minutes of contact.
Google Organic Gardening. org and search for more info.
You may still get a reaction but it may not be as bad. Try it first and then do the doctor thing if you still have to.
http://www.gardensalive.com/article_...cd2=1237912181
peace