They have been itching, scratching, and swelling up. In some cases, even visiting A&E.
“If I have tomato ketchup, or any kind of red sauce, pretty much instantly I get a rash.” “If I eat a lot of beef or lamb, I get itchy and get red in the face.” “By the time I got to hospital, my reaction to the seafood was making me dizzy and I had to sit down.”
I am sitting in on the food allergies clinic, listening to the morning’s patients. They are talking to someone who is not just a specialist, but is one of the foremost experts in food allergies anywhere in the country.
“There is a preservative called sodium metabisulphite that is used to prevent browning in food and is often in vinegars. It may be that you are reacting to that,” she tells one patient.
A dietitian by training, she has been working at Royal Brompton Hospital for a remarkable 47 years and, over that time, has maintained her research into this fascinating area of medicine, and is now a consultant. This gives her an almost unrivalled perspective on food and allergies over a five decade span.
During that time, our diet has changed beyond all recognition. We can now obtain ingredients from almost anywhere across the world in our local supermarkets. We can cook exotic dishes at home with ease, and if we’re dining out, the range of cuisines available is greater than it has ever been.
This boom in dietary change has come with a corresponding increase in food allergies. First it was peanuts, followed by soy and sesame allergies. Now people have allergies to virtually every kind of food. Packaging labels warn us. Waiters ask us. Allergies have become one of the major health issues of our time.
"We rarely saw food allergy in adults before," she says. "Children would typically have milk allergy, egg allergy and, very occasionally, fish allergy. That was about it. But gradually more and more adults started presenting with food allergies, until it was clear that they needed their own clinical service. ."
As our allergies grew, so did scientific understanding. Research increasingly highlighted the importance of dietary diversity, and the early introduction of foods during infancy in preventing food allergy. Also the role of the gut bacteria or microbiome in the development of immunity.
While this widening of diet and public understanding has brought many benefits, it has also created a medical paradox. Those who suffer from reactions linked to foods are now often convinced they have a food allergy and naturally want to have allergy testing to establish a diagnosis.
"I've had people come in and say, 'I'm just here for the allergy test.' But without the patient's story, those test results are often meaningless. There are many people who are suffering with symptoms but don't have a food allergy. Testing for lots and lots of foods is usually really unhelpful.”
A negative allergy test can be highly reassuring. A positive result, however, requires much more careful interpretation. "A test is only one piece of the puzzle. A test result is not a diagnosis. The history is the key. You have to see the whole patient, not just the test result.”
In this field, as in any other, the specialty is merely a doorway to a deeper appreciation of the immense complexity of the human body, a complexity that confronts all who work within this hospital to understand, diagnose and treat it.
"The more we've learned, the more we've realised how much we still don't know." This is as true of food and allergies as of anything else. Some of her patients have spent years on restrictive diets, moving from specialist to specialist, waking up every day wondering what is wrong with themselves, unable to find answers, to be treated, to be cured.
"I see people whose diets have become incredibly limited because they keep cutting foods out one by one." In many cases, she says, the challenge is not simply providing a diagnosis. It is simply helping people to move forward. "Sometimes the help people want isn't the help they actually need."
That can mean gently encouraging patients to reintroduce foods, helping them avoid unnecessary restrictions, or supporting them in managing symptoms even when medicine does not have the answer.
"Patients don't arrive with problems neatly divided into specialties."
This is where her lifetime of work in the hospital really comes to the fore. In an ever-fragmenting world, as true in medicine as anywhere else, it is knowing how the rest of the organisation operates, and who is working on what, that really counts.
Many allergy patients also have gastrointestinal symptoms, respiratory conditions or related issues that require input from multiple teams. Innovative joint clinics have therefore been established, with colleagues in gastroenterology, ENT and other specialties. Some of these were among the first of their kind.
"When clinicians work together, patients don't have to keep starting their story from the beginning."
It is an approach she believes should become more common across healthcare, forged by her experience working at this very special, specialist hospital. Ever since arriving as a young dietitian, she has found an environment unlike anywhere else she has seen.
"I realised how much difference you could make to individual patients." She credits much of her success to supportive colleagues and mentors who encouraged innovation and treated team members as equals. "It didn't matter whether you were a consultant, a dietitian or something else. What mattered was that you were interested and committed to helping patients."
That culture, she says, allowed people to create services that did not exist elsewhere and pursue ideas that might have struggled in other organisations. As discussions continue nationally about how allergy services should be delivered, she believes some allergy care could move closer to patients through primary care and community-based specialist services.
What remains unchanged is the need for expertise, compassion and time to listen. For all the advances in testing and technology, she believes the most valuable tool in allergy medicine is still conversation. "The history is always the most important thing."
Nearly fifty years after she first entered the field, it is a lesson that continues to guide her work every day.