Food allergies are a common fear for parents, having all heard the horror stories of children who have reacted to food items such as nuts, shellfish, and milk. As a result, parents are sometimes reluctant to give their child a specific food type, but providing you pay close attention and monitor their eating habits, there should be little reason to hold off on certain foods.

You may be aware that food allergies are on the increase and that hospital admissions for severe allergic reactions have doubled over the last decade in countries such as the UK and USA. In Australia, admissions for anaphylaxis have increased five fold.

While there is no clear understanding of why this is so, some have suggested that delayed introduction to certain foods is playing a part. Others suggest skin exposure and methods of food processing are to blame.

What is a food allergy?

Sometimes, a person’s immune system will produce antibodies in reaction to a protein in foods which would normally be considered safe. Mast cells recognise, for example,  a peanut as an allergen, and dump IgE antibodies into the tissues as a way to rid the allergen. This is what’s known as an allergic reaction.

A reaction to food can result in an itchy or runny nose, a sore throat, itchy, watery eyes, a rash (hives), skin irritations, vomiting, diarrhea and swelling, which usually appear shortly after consuming the food. Food allergies are common in infants and children, with an estimated one in twenty children between 0 and six years having a food allergy. Many children grow out of these food allergies, and just two in 100 adults suffer from food allergies.

What foods are the most likely to cause a reaction?

The most common food allergies in babies and young children are to lactose, eggs, and nuts such as peanuts and cashews.  It is estimated that 2% of babies are allergic to milk, 5% are allergic to eggs, and just under 2% are allergic to nuts. Other food allergies may be induced by seafood, sesame, soybeans, fish, or wheat, although these are less common.

There are also many foods that may cause a milder reaction, which is referred to as an intolerance. Intolerance reactions are generally less severe than allergic reactions and, unlike allergies, intolerances are not caused by the reaction of your immune system. Even so, an intolerance can be unpleasant for young children. Common intolerances include dairy products, food additives, strawberries, citrus fruit, tomatoes, and foods containing histamines.

When to be cautious

If a family has one child with a food allergy, their brothers and sisters are at a higher risk of having food allergies too. Food allergy screening is possible, but it’s important to note that children can develop allergies at any time and a negative test should not be relied on. In the case of a positive screening test, further studies may need to be carried out.

Do not presume that because you had an allergy as a child that your own children will. There is very little evidence suggesting food allergies are hereditary.

What to look for

If you suspect your child could be suffering from an allergy or intolerance to a particular food, it’s important to monitor them closely. In foods that commonly cause reactions, always pay special attention when trialing for the first time and introduce in small doses.

Symptoms to food allergies will normally present themselves within 30 minutes of the food being consumed. For some children, symptoms can be severe (known as anaphylaxis), and can result in difficulty breathing, swelling of the throat or tongue, coughing, dizziness and/or unconsciousness. Deaths have occurred, although fatal reactions are extremely rare.

Lesser symptoms include reflux, colic and diarrhoea.

Diagnosing an allergy

Sometimes, a child may present the symptoms of a food allergy but the cause is not quite clear. Reliable diagnosis is important in preventing reaction, and in these cases a skin prick allergy test or blood test may be ordered by your GP. Sometimes, a health professional may suggest a temporary elimination diet or food challenges to identify the cause in a safe way.

Can food allergies be prevented?

While there are no clear guidelines on how to prevent food allergies in young children, there are factors that can help reduce a child’s chance at developing an allergy, such as:

• Breastfeeding for at least six months.
• Continuing usual food habits during pregnancy and breastfeeding (not restricting a mother’s diet) excessively.
• Combining solid food with continued breastfeeding.
• Not smoking during pregnancy.

Are you worried about your baby having a food allergy?