Food allergies: Mango?

We think that Auggie had a reaction to mango.  I gave him a big chunk, peel and all, to munch on and lo and behold a few hours later he had hives on his wrists and eczema all over his body :(     I did find out that mango contains urushiol, the same sustance found in poison ivy!  Mango is out for now.  We will have Auggie tested for allergies in May - we'll probably do skin prick tests to rule out specific foods that we suspect such as dairy, soy, mango and others.