Since you ask, "What foods have you reacted to (not stomach/digestive issues so much as low grade itchiness, runny nose, foggy headache, etc...) and how have you handled/improved things?" Here's my response: I have had itchy/runny nose reactions to peanut butter and to bananas, and I cut both items out of my diet completely. For both, it took a long time to figure out that those foods were the culprits. Keep a food journal, and jot down symptoms you experience, what time you have them, etc. so it's a little easier to pinpoint what food might be doing it.

I've also had reactions to nuts (almonds mostly) that involved really bad, two-day-long headaches. With the nuts it seems to be dose dependent (I can get away with a little but not a lot!). Since I don't do moderation well, I've cut nuts out completely.

I have since added bananas back into my diet but on a 4-day rotation, and things seem fine so far. I have been trying to actually put my entire paleo diet into a strict 4-day rotation but sometimes I get lazy. To be quite honest, all the supplementing of enzymes/HCl, l-glutamine, probiotics, etc. has not improved my food reactions; only elimination and careful reintroduction on a rotation basis has helped anything. Oh, and of course being PALEO in the first place made a big difference in seasonal allergies. But now it's the tweaking to get rid of the food rxns and remaining symptoms.

I have to stress, that if you do go the elimination route and your symptoms improve, leave that food out of your diet for a long time (several months even?). If/when you reintroduce, don't go back to eating it everyday or in large quantities, because you run the risk of becoming "allergic" again.

A book I found helpful regarding food families and rotating foods was If This Is Tuesday, It Must Be Chicken.

If someone else has more effective strategies than elimination/rotation for food reactions, I would be so grateful to hear about them! Please share!