I suspect my daughter has an intolerance to flavour enhancer 635 because we have noticed reactions to the noodle flavour sachet and since then she has had a few reactions (itchy rash) to other snack-food products containing 635. A recent bout seemed likely to have been set off by eating sour cream and onion flavoured Pringles. Although the tiny print on the box does not list 635 or ribonucleotide, it lists the two other flavour enhancers which 635 is made from (627 and 631). We had let our guard down as she had not had a reaction for some time and begged on the school holidays to have the Pringles. Her rash seems to also flare up when she goes in the swimming pool, so obviously it is more complicated than I thought ... once a few years ago she got an insect bite which swelled, and then for about a week she'd get a rash when going in the school pool or our pool at home. It eventually went away, and she's been fine swimming for years, until now. But the cross reactivity (is that what you call it?) in the past with the insect bite, and now with the 635 (if that is indeed what it is) and the pool water shows how allergy/intolerance ain't that simple. Has anyone else noticed subsequent problems with rash flaring up when going in a swimming pool?  – by email