Yesterday’s story here in the Express about unorthodox food hypersensitivity tests frustrated me a bit.
Once again it’s the unsatisfactory tactic of using an inappropriate patient as a case study. In previous examples, such as the example in the Times earlier this year which I wrote about here, we’ve seen someone without any apparent health problems taking the tests. This time, it’s a food allergic child being employed to discredit already discredited food intolerance tests. It’s a flawed premise.
These tests are nonsense, of course – that much is known. Yes, it’s important this message gets out there – though the ongoing availability of these tests and the fact their practitioners remain in business would suggest it’s doing little good.
It may be doing no good because the public is confused – mostly about the difference between allergy and intolerance, I’d hazard. I don’t blame them for this – we can’t expect them to know. But I do think the core differences could be explained simply and basically in a few words. Roughly:
* a food allergy is usually rapid, sometimes alarming, very occasionally life-threatening, and is characterised by symptoms such as rashes, watery eyes/nose, wheezing, swelling etc
* a food intolerance is slower, rarely serious, and usually causes gut-based symptoms.
Articles like this fail to adequately draw the distinction between the two, and do little in my view to clarify it in the minds of readers. I don’t necessarily put the blame on the journalist Jane Symons for this: I’ve no doubt at all she want to see sham tests exposed and dissed as much as I do. But when practitioners of these tests talk of ‘allergy’ what they really mean is ‘delayed allergy’ – their term for ‘intolerance’, essentially. This does need to be understood and explained.
Further, when the title of an article is “Allergy Tests: What works” then I feel a major national newspaper has a duty to deliver on that promise fully and communicate clearly what does work in allergy testing – that is, orthodox (IgE) blood tests, skin pricks, and possibly challenge testing – and what does work in intolerance testing – that is an elimination and reintroduction diet under dietitian’s supervision, or breath tests for lactose intolerance, or blood tests and biopsy for coeliac disease (auto-immune gluten intolerance).
And the evidence for alternatives is absent. It’s that simple really. And you don’t really need a poor little kid with a nut allergy to make that point.