Doctors today have warned of a little-known food allergy often mistaken for hay fever.
One in 50 Britons is thought to suffer from pollen food syndrome – a reaction caused by eating raw fruit or vegetables.
It is usually harmless and causes a runny nose, sneezing and itchy eyes.
But according to Dr. Sabah Salman, the allergy may turn out to be more serious.
The GP, who works in South London, said: ‘More extreme symptoms can occur, such as nausea, vomiting, difficulty swallowing and difficulty breathing.
Airborne food particles can cause sneezing, a runny nose and eye irritation, and peeling fruits and vegetables can cause skin irritation. Although rare, more extreme symptoms such as nausea, vomiting, difficulty swallowing, and difficulty breathing can occur
“Of course, you should always seek urgent medical treatment in this case.”
Food pollen syndrome – a hypersensitivity that can also be caused by eating nuts – often affects hay fever sufferers.
Dr. Salman, who works with the Lloyds pharmacy, added: ‘Many plant foods have a protein structure very similar in shape to the pollen in the types of trees, grasses and weeds that cause hay fever.
“Your immune system doesn’t always recognize the difference between the pollen you breathe in from things like trees, and the pollen structure in food you eat.”
“Essentially, pollen food syndrome arises when the immune system recognizes the food protein you’re eating as an allergen and triggers an allergic reaction.”
She added that this causes similar symptoms to hay fever, the season of which is now in full swing.
Raw apples, peaches, kiwis, almonds and hazelnuts are common triggers.
Symptoms — which may also include mild swelling of the lips, tongue, lining of the mouth, ears, and throat — usually appear within 10 minutes of eating the offending food.
Dr. Salman said: ‘Some people notice symptoms just from preparing food.
“For example, airborne food particles can cause sneezing, a runny nose and eye irritation, and peeling fruits and vegetables can cause skin irritation.”
Mild symptoms usually go away within an hour without treatment and drinking water.
The allergic reaction can be triggered by plant foods such as fruits and grains. These foods have a protein structure very similar to the pollen in the types of trees, grasses and weeds that cause hay fever
Dr. Salman added: ‘If you’ve taken an antihistamine but your symptoms don’t improve you should seek medical advice.
‘If you have a food allergic reaction that affects your breathing or circulation, for example causing you to pass out, don’t rely on antihistamines or an asthma inhaler. Instead, speak to a medical provider urgently.”
Many patients with food pollen syndrome can tolerate reactive foods when cooked or canned, even if they cannot eat the food raw without causing symptoms.
This is because they are “denatured,” Dr. Salman said.
Dr. Salman said: ‘This means that a soup containing allergic foods may not cause any symptoms, but a stir-fried vegetable – which has been cooked very gently – could be a problem.
“Some people also find they can tolerate certain types of the same foods. For example, one apple variety can provoke reactions and the other cannot.’
Despite Dr Salman’s warning, very few Britons have even heard of the allergy.
A survey conducted by Lloyds Pharmacy of 500 Britons found that 78 percent had never heard of food pollen syndrome.