Xolair is a monthly anti-IgE injection FDA approved for the treatment of severe asthma.  DS's asthma was bad enough he qualified for it even though my primary reason for wanting him on it was his multiple life threatening food allergies.  After just a few months of Xolair, his asthma was gone and so were most of his food allergies - and the ones that didn't completely go away, his tolerance was much higher.  After several years of Xolair, we lost our insurance and DS had to discontinue treatment.  Over the past few years without it, his asthma has been fine, but his food allergies are slowly returning.  Unfortunately, he can't go back on Xolair since his asthma is fine. 

Thankfully true corn allergy is rare because corn is in everything and it doesn't have to be labeled.  I'm thankful every time I buy food that DS's corn allergy didn't come back after Xolair.

Generally speaking, sugars and oils derived from allergens tend to have very little if any protein left to cause a reaction.  DS did react to corn sugars (or I guess it could be other unlabeled corn in the products he reacted to) and I react to peanut oil, so there's at least a tiny amount of protein left.

I personally do not have a corn allergy (yet) but one of my neighbor's sons does.  But the other day he was eating marshmallow Peeps, which I had intentionally not bought for him because they contain corn syrup.  Does it not contain the same allergens?