IS A FOOD ALLERGY THE REAL CAUSE OF YOUR DISCOMFORT?
EXPERTS believe as many as one in 20 people may have a condition called eosinophilic oesophagitis, often misdiagnosed as chronic reflux.
This condition is an allergic response to certain foods in the oesophagus. White blood cells called eosinophils (the same cells involved in hay fever and asthma) build up in the lining of the oesophagus, causing difficulty swallowing.
‘It’s a very topical area,’ says gastroenterologist Professor Peter Whorwell. ‘About ten or 15 years ago doctors started noticing that in some people with heartburn, when you biopsy [remove tissue from] their oesophagus it turns out to be stuffed with eosinophils.’
‘Because doctors are looking for it now, we are seeing it much more,’ adds Dr Adrian Morris, an adult and children’s allergy consultant at the Royal Brompton Hospital and Surrey Allergy Clinic. ‘It’s actually quite common. I expect it to be as much as 5 per cent of the population.’
He says adults affected typically have difficulty swallowing, and, crucially, don’t respond to typical reflux medications such as antacids or proton pump inhibitor drugs (PPIs).
Professor Whorwell says eosinophilic oesophagitis may be a factor in those patients with so-called non-erosive reflux disease, who complain of reflux symptoms yet their oesophagus isn’t inflamed when examined. ‘Gastroenterologists don’t tend to do biopsies so they miss it, but you definitely should in someone with non-erosive reflux because it could be a case of eosinophilic oesophagitis,’ he says. As for treatment, eosinophilic oesophagitis is an allergy to dairy products, egg, wheat, soy, fish or nuts, and so once it’s diagnosed patients must cut these out of their diet and reintroduce them one by one to establish which causes the problem. That food must then be avoided for the rest of your life, says Dr Morris. Inhaled steroids — like those used in asthma — improve symptoms, too. Doctors are also finding that some cases of reflux are nothing to do with a weakened oesophageal valve, and are instead caused by small intestinal bacterial overgrowth (SIBO). ‘Food starts to get broken down by excess bacteria in the small bowel before it can be properly digested by the large bowel and that creates indigestion, gas and belching,’ says gastroenterologist Dr Anthony Hobson. ‘Treating that often gets rid of the reflux.’ Ironically, he adds, PPIs have been shown to cause SIBO, so coming off them often helps, while some patients may need a short course of antibiotics to clear the excess bacteria. If a doctor suspects SIBO, you may be referred for a breath test to measure levels of hydrogen after consuming a sugar solution — the gas is produced by gut bacteria. If hydrogen rises 30 minutes to an hour afterwards, too soon for the food to have reached the large intestine, this is evidence of bacteria in the small intestine.