Definitely wash well all over. You and him. Any oils on you can just transfer back to him. Use a soap intended to cut oil. The allergen in the plant - urushiol - is an oil. It doesn't break down easily. If you are really concerned there are soaps designed specifically to wash off poison ivy. Any grocery/drug store should carry some brand of it.
There are some natural remedies in nature - jewel weed for one - but I'm assuming you don't really have access to that right now.
First exposure to poison ivy does not cause a break out. Repeated exposures may. Assuming you know this was your child's first exposure he shouldn't have any problems.
If he does break out, there are otc treatments and plenty of home remedies. Oatmeal baths, etc. I'm sure a web search will get you plenty of info. There is also a product called zanfel that is supposed to be good. It bonds back to the ivy's oils in your skin to wash them off even after you've broken out. Never used it personally but wouldn't hesitate to try it know that I know about it, though it is pretty expensive. I know you can get it at walmart but not sure where else.
Wash both of your clothes really well in detergent that will cut oils and you should be good.
Originally Posted by MrsMike
I can practically take a bath in it and not break out. Hopefully he is the same.
Don't count on this. You can develop the allergy to poison ivy at any time in your life. Not saying you will - but still treat the plant with respect.
Start pointing it out to your ds every time you see it. Both my kids could recognize it at an early age and knew to stay away from it, for their sakes and mine. The last few cases I've gotten were indirect contact from my kids so I started making sure they knew how seriously we could all be affected.
I've had some pretty bad, miserable cases. I really hope your little guy doesn't break out.