Ethan had a reaction to peanut butter when he was under 1(he took a bit of my pb on toast when I wasn't paying attention), maybe 11 months old. He got a rash on his cheeks and a little bit on his tummy. I made sure he avoided nuts (of all kinds, except his parents haha), and he had another reaction a few months ago when Mike gave him a "coconut" chocolate, which turned out to be a Ferrero Rocher, (hazelnut chocolate).
I got him referred to an allergist, just so I could know one way another if he was allergic to nuts or if I was being paranoid. Turns out he IS allergic to peanuts. The allergy specialist said he might outgrow it. Kids with a mild rash like allergy have a 20% chance of outgrowing it. the good news is that he's not allergic to tree nuts (peanuts are in their category because technically they're not tree nuts). And he's not allergic to anything else. His banana problem is a food intolerance, not a true allergy. I'll keep him away from bananas for another few months and try again in the fall (if we ever get a quiet weekend to test it out).