So, the new thing where I live (both IRL and online) is to try to match a particular (-ly restrictive) diet to your or your kids' symptoms to see if said issues improve. A good number of mothers of my kids' preschool classmates are trying different combinations of gluten-free, casein-free diets for both themselves (allergies) and their children (aphraxia, autism).
My son's behavior and his eczema are aggravated, I've noticed, by artifical colors (red 40 and yellow 5, in particular), MSG, citrus, tomatoes, and who knows what else? Because I am all about making my life more difficult, I am going to try the FAILSAFE diet, also known as the RPAH Elimination Diet, to see if it produces an improvement in my son's defiance and impulsivity, and his eczema too. After you follow the bare-bones diet for several weeks, or until you see an absence of the symptoms you're investigating, then you challenge it by adding items high in the substances you suspect are triggers. That way, you know what you can safely build back in to your diet, and what you need to avoid in the future.
I've been researching this diet for months, and am preparing for us to spend four weeks on it, including several challenges for the forbidden substances: amines, salicilytes, glutamates, and synthetic additives. If nothing changes, and nothing shows up, I may need to see if gluten or casein may be an aggravator.
Ideally, we will start the day after preschool lets out for the summer. I'll keep you posted.