We didn't get the easy answer we were hoping for.
Danny doesn't have any allergies.
The allergy doctor was great. He was very gentle and thoughtful. He spent a ton of time talking to us about his thoughts and where he would suggest we look next. He gave us a lot of very thoughtful input on his perspective both as a parent and a physician. He told us even before the testing that he didn’t think the problem was allergies, but he would go ahead and test just to rule it out. He thinks maybe some kind of metabolic disorder and that we should have the pediatrician do a ‘failure to thrive’ workup on him. He offered to help us in any way he could, if we don’t get the results we want from our pediatrician.
So that's what I know for now. Next step is back to the pediatrician.