I commonly see children who have been put on unnecessarily restricted diets

EVEN if you’re not a sufferer yourself, the chances are you know someone who avoids certain foods because they believe they’re allergic or intolerant to them.

Increasingly, research is showing they may be right.

Figures from charity Allergy UK suggest allergies are a major health problem.

About 21million adults in this country suffer from at least one allergy, ranging from hay fever, eczema and asthma to insect stings, pets and food.

Every year, the number of sufferers increases by five per cent – and research confirms that in recent years, there’s been a particularly dramatic rise in food allergies, especially among children.

According to Allergy UK, cases of food allergies have doubled in the past decade and the number of hospital admissions caused by severe allergic reactions has increased sevenfold.

But how can we tell if we really are allergic to a food – and which are the most likely culprits? ALLERGY OR INTOLERANCE? “A food allergy is a reaction produced by the body’s immune system,” said Laura Forwood, dietitian for healthcare company Abbott.

“With an immediate allergic reaction to a food, your skin can be itchy or swell, you may feel sick or vomit and experience stomach pains and diarrhoea.

“Although rare, some people can experience severe, sometimes life-threatening, symptoms which require immediate medical attention.

“This is known as anaphylaxis and symptoms can include swollen eyes, face or lips, feeling light-headed or faint, or loss of consciousness.”

If someone is suffering this badly, dial 999 and request an ambulance.

In contrast, a food intolerance doesn’t involve the immune system.

Laura said: “Symptoms tend to vary more and because people sometimes react hours or days later, it can be difficult to identify the exact food that’s caused the reaction.

“Intolerances primarily affect the gut, such as stomach pain or bloating, but eczema or itching are also common.”

According to the British Society for Allergy & Clinical Immunology, six to eight per cent of children and up to four per cent of adults have a true food allergy. One in five people alters their diet because they believe they have a food intolerance, although experts believe the true incidence is much lower than this. THE MAIN OFFENDERS The British Dietetic Association say about 90 per cent of food allergies in children are caused by just eight foods – wheat, cow’s milk, eggs, fish, shellfish, soy, peanuts and tree nuts, such as almonds.

But any food can cause an allergic reaction and sesame, citrus fruits and kiwi seem to be becoming more common culprits. Meanwhile, in adults, allergies to fish, shellfish, peanuts and tree nuts are often seen.

Surprisingly, another common food allergy is to raw fruits and vegetables, especially in hay fever sufferers. This is because the proteins in pollen from trees, grasses and weeds have a similar structure to those in fruit, veg and nuts.

In hay fever sufferers, the