Definitely MM, although we find here it is additives rather than sugar that causes a problem. But often the things with additives are sugary! Preservatives, colours, flavours, all of them can set DS off. I am an obsessive label-reader when buying food now, I scrutinise everything. I choose a product not by it's price, but by it's contents. It's actually pretty common for kids to be affected by additives, as you are probably gathering . Just that usually no one tells us about it, we have to figure it out for ourselves .

Trillian, sounds alot like your nephew could have a salicylate sensitivity. There are lots of fruits that are high in salicylates, and for people who are sensitive the symptoms can be horrible (and vary widely). It's very upsetting, because you feel that fruit is a great healthy thing for your kids to be eating, but if you know it affects them it's just not worth it . Not that you can't have ANY fruit, just not those that are very high in salicylates. There is actually a website that I think is called 'salicylate sensitivity', which is quite interesting.