Asthma of the esophagus: the alarming emergence of a rare inflammatory condition

Lisa Thornton was heavily pregnant and in her early thirties when she felt a blockage in her esophagus, the muscular food pipe that connects the mouth to the stomach. “At the time I thought it was just the pregnancy,” says Thornton, now 50, who lives in the New Forest in Hampshire. “I thought everything was going up. But a few years later it got worse.”

During a Sunday roast with her family, a piece of broccoli suddenly got stuck in her throat, causing cramps that lasted for hours. Every attempt to rinse it away with water failed as the liquid simply came back up. Thornton drove to a nearby walk-in center, where doctors tried unsuccessfully to clear the blockage with muscle relaxants.

After almost 20 hours she ended up in the Emergency Room. “I was put on an IV and the doctors started talking about surgery to straighten my esophagus to release the obstruction,” she recalls. “As a last ditch effort, a young doctor gave me morphine (which has both a muscle relaxant and a painkiller). I woke up to find that after 36 hours the lump had finally disappeared. It had been a violent, shocking experience and no one seemed to know why or how.”

But this was just the beginning. It would be 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 an inch wide when relaxed, it can extend more than three times as wide to accommodate particularly large chunks of food.

“It is common to swallow a piece of solid that is two to two and a half centimeters in size,” says gastroenterologist Prof. Stephen Attwood. “The esophagus must be stretchy to open and allow food to pass through.”

But in patients like Thornton, the lining of the esophagus becomes chronically inflamed, causing it to become stiff, swollen and unable to stretch, as well as prone to food blockages. The condition is caused by an excessive immune response, triggered 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 they can cause allergic reactions and eczema.

White blood cells known as eosinophils. Photo: Nephron/Wikipedia

When Attwood EoE first identified in the late 1980sit was extremely rare, with estimated rates of less than 10 per 100,000 people. But like food allergies, which are also mediated by eosinophils, EoE is becoming 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 the disease now affects around 63 in 100,000 people, which Attwood says is enough to technically make it ‘a common disease’.

A 2022 study in Sweden even suggested it could affect more than one in a thousand people – twice as many. “That is the highest current estimate, but it fits perfectly with what we see in daily practice,” says Attwood. “More and more patients need to be assessed for these swallowing problems and we know we are diagnosing this more and more.”

So what’s going on? Hannah Hunter, an allergy dietitian at Guy’s and St Thomas’ NHS Foundation Trust, has been treating patients with EoE for the past decade and points to several theories – theories that have also been linked to the rise in cases of allergy, asthma, eczema and hay fever . One of the most talked about is the hygiene hypothesisthat attributes the rise of EoE to modern cleanliness, which results in fewer infections in children to train the immune system, making it more susceptible to going wrong.

Long-term damage to the delicate cells lining the esophagus from modern diets and common chemicals such as pesticides And detergents have also been discussed as a plausible explanation.

“Data suggests there is a real increase that cannot be explained simply by increased awareness,” Hunter said. “There are many theories as to why – less exposure to microorganisms early in life, low vitamin D levels and more exposure to highly processed foods that contain additives, preservatives, sweeteners and emulsifiers.”

But although EoE is on the rise, awareness among many GPs is limited. Reports show that it takes an average of six years for patients to receive the correct diagnosis. Although there is now an effective drug known as budesonide, whose brand names include Jorveza, many patients are misdiagnosed with indigestion or gastroesophageal reflux disease.

If left without proper treatment for years, EoE can progress to the point where patients leave thick scars in their esophagus, preventing them from eating normally or swallowing even a small tablet.

Prof. Kamila Hawthorne, president 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 all medical specialties, yet the shortest training programme, at just three year. Full diagnosis (of EoE) requires a thorough examination and sampling of the esophagus in secondary care.”

Diagnostic companies are now working on ways to make it easier for doctors to pick up EoE without the need for a full endoscopy, which involves inserting a long thin tube containing a small camera down the patient’s throat. The Cambridge-based gastrointestinal health care company launched in December Cyted announced it had received a £1 million grant from Innovate UKthe UK innovation agency, to expand the use of its EndoSign capsule sponge test (commonly used to diagnose and monitor Barrett’s oesophagus, a precursor to oesophageal cancer) for EoE.

“This would allow patients to be tested faster and with less discomfort than an endoscopy, but with the same accuracy,” said Marcel Gehrung, CEO and co-founder of Cyted.

Hunter says we still need to understand more about the role of different foods in causing the underlying inflammation that drives EoE, most commonly cow’s milk, wheat and eggs. Although EoE is very different from the reactions often associated with food allergies, certain foods are known to potentially worsen symptoms.

“It would be good to know more about the role of diet in inflammation, apart from specific food triggers,” says the allergy dietitian. “There is evidence that the way we eat can influence our immune system and therefore have an effect on EoE. Highly processed foods, sugar and trans fat can have a harmful effect.”

For Thornton, EoE meant that her entire life quickly became focused on avoiding other foods and increasing anxiety around food, especially in social situations. Because she had been misdiagnosed for so long, she didn’t know there was a new drug for the condition until a chance meeting with Attwood two months ago, brokered by a patient organization.

Based on Attwood’s recommendations, she switched to a new consultant and recently started taking Jorveza, which has already made a marked improvement in her life.

“It should be diagnosed much sooner because it has such an impact on your life,” she says. “I’ve been taking Jorveza since just before Christmas and it has made such a difference. I even ate a steak last week, which I never would have done before.

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