M.G.
It does appear to be an allergy of sorts. My youngest son is highly allergic to milk and eggs. We have had him tested for every allergy you can think of. It helps to find out what exactly they are allergic to so that you can catch it early. It will help to have you avoid it. Maybe going to an allergy specialist instead of just the pediatrician. It has helped us to have both. We have been able to keep him well now for over a year now due to knowing what we have to avoid. Good luck, I know it is frustrating.