Hi , i too go through this on a regular basis. It makes you question whether its die off or allergic reactions. If you are following the diet and not cheating then take it its a die off. If however you have eaten something you shouldnt have then take it that its a reaction.
Saying that its complicated because I cant eat tomatoes without itching to death and yet I am allowed them.
I write down everything I eat and then do an elimination. I know now pretty much what to avoid but I am going for an allergy test so I dont ave to use myself as a guinea pig lol.
Ive also read that taking large doses of vitamin c helps with die off. you cant overdose on it because it flushes out.
Do the food dairy , keep to the diet and stay with it. Its horrible but if its die off it wont last long. Look after yourself