A new study has demonstrated for the first time that adults born and living in the UK can develop a severe food allergy to plant foods.
The research, published earlier this year in the journal Allergy, was led by experts at Royal Brompton and King’s College London in London and featured in national media on 19 May. Called Lipid Transfer Protein (LTP) allergy, it is named after the type of proteins in fruits, vegetables, nuts, seeds and cereals that cause the reactions.
LTP allergy was previously thought to be confined to people in Mediterranean countries, particularly Spain and Italy; it usually occurs in adults and can cause severe allergic reactions, including anaphylaxis, to raw, cooked and processed plant foods.
The Mail on Sunday reports how: ‘As the year-round demand for exotic fruits and vegetables has increased, so too has the number of people suffering from a new type of severe food allergy.’
A patient of Royal Brompton’s specialist allergy team, Jodie Jackson, told the Mail on Sunday that the allergy tests conducted by her GP were inconclusive, ‘so she was referred to London’s Royal Brompton Hospital, a leading centre for allergy treatment. In January, experts there diagnosed her with LTP. The condition was thought to affect only people from Mediterranean countries such as Italy and Spain who eat diets packed with the allergy triggers.’
Dr Skypala, consultant allergy dietitian at Royal Brompton is one of the study’s lead authors and established and chairs a Europe-wide task force to better understand how to manage and treat LTP allergy.
Dr Skypala explained: “People with this allergy react whether an ingredient is cooked, raw or in a processed food. For example, those with the most common form of fruit and vegetable allergy, called pollen food syndrome, will only react to raw tomato. But those with LTP allergy might react to raw tomato and tomato puree on a pizza, for example.”
LTP allergy symptoms can include swelling of the eyes, mouth and throat, severe gastrointestinal pain, rash and difficulty breathing.
Stephen Till, an allergy professor at King’s College London and a consultant allergist at Guy’s and St Thomas’ hospitals, added: “For many years we’ve known about this allergy in other southern European countries. We’re now seeing patients with it here – and numbers are increasing, as with all food allergies. The increased incidence might be related to dietary habits changing. Tomatoes and strawberries are much more available now than they were decades ago so LTP allergic people may be more exposed to triggers.”
The importance of a definitive diagnosis
The research is likely to lead to an increase in diagnoses of LTP allergy, especially in people who have had previously unexplained reactions to certain foods.
Dr Skypala said: “Patients with LTP allergy may have suffered from severe or even anaphylactic reactions to certain foods, but not ever have received a definitive diagnosis of why these occur. The problem is that LTP allergy is not well-known, and thought not to exist in the UK. We have shown that people in the UK do have LTP allergy and it is no different to the LTP allergy seen in Italy.
“What’s more, people with LTP allergy might only have an allergic reaction to a food when they combine that food with a ‘co-factor’. These include exercise, alcohol or painkillers. In other words, they can eat the food without any symptoms at all, but if they eat the food and have an alcoholic drink or go for a run after eating, they might then have a reaction.”
Professor Till added: “Our research shows that medical professionals need to be aware that someone may be suffering from an LTP allergy, particularly if there are unexplained and severe reactions triggered by plant-based foods.
“Furthermore, not all foods containing LTP allergens have to be labelled on food packaging, so it’s important that people discuss any allergic reactions to plant foods with their GP, who can refer them to a specialist allergy service.
“This will ensure they get a definitive diagnosis so they know exactly how to manage their allergy. The diagnosis may help to identify which foods are more likely to cause a reaction in people with LTP allergy, and they can be given a plan on when to take medication, and what medication to take. Many patients with LTP allergy will need to carry adrenaline, as anaphylaxis can occur and may be unpredictable. Often however, some dietary advice may reduce the risk of further reactions.”
Jodie added: “I now know what fruit to avoid, and that removing the seeds helps. I also know what to do if I do have a reaction, and have been prescribed an adrenaline injector in case of a serious attack.”