Lisa Thornton was heavily pregnant and in her early 30s when she noticed the feeling of a blockage in her esophagus, the muscular food pipe that connects the mouth to the stomach. “At the time I just thought it was just the pregnancy,” says Thornton, now 50, who lives in the New Forest in Hampshire. “I thought it was all pushing up. But a few years later, things started to get worse.”
During a Sunday roast with her family, a piece of broccoli suddenly got stuck in her throat, causing spasms that lasted for hours. Any attempts to wash it off with water failed as the liquid simply came right back out. Thornton drove to a nearby walk-in center, where doctors tried, without success, to free the blockage with muscle relaxants.
After almost 20 hours she ended up in A&E. “I was put on a drip and the doctors started talking about surgery to stretch my esophagus to release the obstruction,” she recalls. “As a last resort, a young doctor gave me morphine [which has a muscle relaxant effect as well as being a painkiller]. I woke up to find that, after 36 hours, the lump had finally cleared up. It was a violent, shocking experience and no one seemed to know why or how.”
But that was just the beginning. It would take another decade, and more incidents, before Thornton finally received a diagnosis: a little-known condition called eosinophilic esophagitis (EoE), or asthma of the esophagus.
Few of us think about how much we rely on our esophagus on a daily basis. Normally less than a centimeter wide when relaxed, it can stretch more than three times its width to accommodate particularly large pieces of food.
“It is common to swallow a piece of solids that is two to two and a half centimeters in size,” says consultant gastroenterologist Prof Stephen Attwood. “The esophagus has to have that elasticity to be able to open and let food through.”
But for patients like Thornton, the lining of the esophagus becomes chronically inflamed, making it stiff, swollen and unable to stretch, as well as prone to food blockages. The condition is caused by an excessive immune response, driven by specialized white blood cells known as eosinophils. We need these cells to eliminate harmful gut bacteria and parasites, but when the immune system becomes miswired, it can cause allergic reactions and eczema.
When Attwood EoE was first identified in the late 1980s, it was vanishingly rare, with estimated rates of less than 10 per 100,000 people. But like food allergies, which are also mediated by eosinophils, EoE has become increasingly common in all age groups, from young children to the over 70s, for reasons we don’t fully understand.
Estimates from the British Society of Gastroenterology suggest that it now affects around 63 in 100,000 people, which Attwood says is enough to technically make it “a common disease”.
One 2022 study in Sweden even suggested that it could affect more than one in 1,000 individuals – twice as many. “This is the highest current estimate, but it fits perfectly with what we see in day-to-day practice,” says Attwood. “More and more patients are coming through in need of assessments for this swallowing problem and we know we are diagnosing it more often.”
So what’s going on? Hannah Hunter, an allergy dietitian at Guy’s and St Thomas’ NHS Foundation Trust, has seen patients with EoE over the past decade and points to several theories – one also linked to the rise of allergy, asthma, eczema and hay fever cases. Among the most discussed are the hygiene hypothesiswho attribute the rise of EoE to modern cleanliness leading to fewer childhood infections to train the immune system and therefore make it more susceptible to going awry.
Long-term damage to the sensitive cells that line the esophagus from modern diets and common chemicals such as e.g. pesticides and cleaning agents has also been discussed as a plausible explanation.
“Data does suggest that there has been a real increase that is not simply explained by increased awareness,” says Hunter. “There are many theories as to why – less exposure to microorganisms at an early age, low vitamin D, and more exposure to highly processed foods that include additives, preservatives, sweeteners and emulsifiers.”
But while EoE is on the rise, awareness is among many GPs is limited. Reports suggest that it takes an average of six years for patients to be correctly diagnosed. While an effective medicine known as budesonide, whose brand names include Jorveza, is now available, many patients are misdiagnosed with indigestion or gastroesophageal reflux disease.
If left without the appropriate treatment for many years, EoE can progress to the point where patients are left with thick scarring throughout their esophagus, resulting in them being unable to eat normally or even swallow a small tablet.
Prof Kamila Hawthorne, chairperson of the Royal College of General Practitioners, says it is not easy for doctors to detect such a condition: “GPs have the broadest curriculum of any medical specialty, yet the shortest training programme, at just three year. Complete diagnosis [of EoE] requires a thorough examination and sampling of the esophagus in secondary care settings.”
Diagnostic companies are now working on ways to make it easier for doctors to pick up EoE without the need for a full endoscopy, where a long thin tube with a tiny camera is inserted down the patient’s throat. In December, the Cambridge-based gastrointestinal health company Cyted has announced that it has received a £1m grant from Innovate UKBritain’s innovation agency, to expand the use of its EndoSign capsule sponge test (commonly used to diagnose Barrett’s esophagus, a precursor to esophageal cancer) for EoE.
“This will allow patients to be tested faster and with less discomfort than an endoscopy, but with the same accuracy,” says Marcel Gehrung, CEO and co-founder of Cyted.
Hunter says we still need to understand more about the role of different foods in triggering the underlying inflammation that drives EoE, most commonly cow’s milk, wheat and eggs. While EoE is very different from the reactions commonly associated with food allergies, certain foods are known to potentially worsen the symptoms.
“It would be good to know more about the role of diet in inflammation beyond specific food triggers,” says the allergy dietitian. “There is evidence that the way we eat can affect our immune system and therefore have an effect on EoE. Highly processed foods, sugar and trans fat can have a detrimental effect.”
For Thornton, EoE meant that her entire life soon centered on avoiding different foods and a worsening anxiety about eating, especially in social situations. After being misdiagnosed for so long, she was unaware there was a new drug for the condition until a chance meeting with Attwood two months ago, mediated by a patient organisation.
Based on Attwood’s recommendations, she switched to a new consultant and recently started taking Jorveza, which has already had a marked improvement on her life.
“It needs to be diagnosed much faster as it has such an impact on your life,” she says. “I have been taking Jorveza since just before Christmas and it has made such a difference. I actually had a steak last week, which I would never have done before.”
