Food allergies

IgE-mediated food allergies can cause mild to moderate symptoms in multiple parts of the body, including:

• swollen face, lips or eyes
• hives or welts on skin
• stomach ache or vomiting.

IgE-mediated food allergies can also cause anaphylactic reactions which cause breathing and heart symptoms and may be life-threatening. Anaphylaxis symptoms include:

• difficulty breathing or talking
• swollen tongue or throat
• wheezing or coughing
• dizziness
• skin that is paler than usual
• floppy.

Non-IgE-mediated food allergies mainly cause digestive symptoms and do not cause anaphylactic reactions. They are generally not life-threatening.  

Symptoms do not appear immediately, it can take between 4 hours to a few days after allergen exposure. The exception is Food protein-induced enterocolitis syndrome (FPIES) which causes symptoms within 4 hours of eating the allergen.  

Common non-IgE-mediated allergies include:

• Food protein-induced enterocolitis syndrome (FPIES)
• Food protein-induced allergic proctocolitis (FPIAP)
• Food protein-induced enteropathy (FPE)
• Coeliac disease

Mixed-IgE/Non-IgE-mediated food allergy symptoms can take days to weeks to appear. Symptoms can appear as common digestive issues including:

• vomiting
• reflux-like symptoms
• redness and irritation of the skin.  

Mixed-IgE and non-IgE-mediated food allergies include:

• Eosinophilic esophagitis (EoE)
• Atopic dermatitis.

Blood and skin prick tests are useful in showing if a child may be sensitive to an allergen or may have a food allergy. Skin prick tests are not available for all allergens.

Blood and skin prick tests are not as useful to confirm if a child has outgrown their food allergy.  

An oral food challenge (OFC) is currently the gold standard test to confirm if a child:

• has an allergy or is sensitive to an allergen, after a positive blood test or skin prick test
• will have an allergic reaction to a particular food when unsure of what is causing the reaction
• can eat an allergen if it is prepared differently, for example raw, baked or cooked
• has outgrown a diagnosed food allergy.

An oral food challenge will generally be done in a hospital for close medical monitoring.

Tests used to diagnose allergic conditions such as FPIES, FPIAP, FPE, Coeliac disease, EoE and atopic dermatitis may include endoscopies, colonoscopies and biopsies. 

Definition:

Endoscopies and colonoscopies involve a procedure where a camera is inserted into the mouth or the rectum and is used to look for signs of damage to the digestive system or the bowel.  

A biopsy is where cells or tissue are removed from the body and tested for signs of allergic conditions. 

Some tests advertised are not scientifically proven to diagnose or confirm food allergies. These tests include:

• cytotoxic food testing
• kinesiology
• electrodermal testing
• pulse testing
• reflexology
• hair analysis.

Using unproven tests to diagnose or confirm a food allergy could result in:

• an incorrect diagnosis
• incorrect treatment 
• avoidance or unnecessary removal of food groups from the diet. 

Removing certain foods from a child’s diet may lead to nutritional deficiencies and failure to thrive. 

The current gold-standard treatment for a food allergy is strict removal of the allergen from the child’s diet. 

Milk or egg allergies may be an exception. An Oral Food Challenge (OFC) could show an allergy to lightly cooked or raw milk or egg but is tolerated if it is baked. The allergy specialist may advise that baked egg or milk does not need to be removed from the child’s diet. 

Medications to treat allergy symptoms include:

• antihistamines
• prostaglandin synthetase inhibitors
• corticosteroid. 

For severe reactions like anaphylaxis, the only effective treatment is Epinephrine, commonly known as Adrenaline. Adrenaline comes in the form of an injector. EpiPen® and Anapen® are adrenaline injectors approved and available in Australia for the emergency treatment of anaphylaxis. 

Images sourced from the Australasian Society of Clinical Immunology and Allergy (ASCIA) 2024.

The Australian Society of Clinical Immunology and Allergy does not currently or routinely recommend Oral immunotherapy (OIT) for food allergies.

Oral immunotherapy is an emerging and possible treatment for a food allergy. Under medical supervision, a small amount of the food allergen is eaten or drunk daily. The amount gradually increases until a target amount is reached and regularly consumed.

Oral immunotherapy aims to achieve:

• desensitisation - when larger amounts of the allergen can be consumed before causing allergic reaction symptoms
• sustained remission - when the allergen can be consumed in unlimited portions without a reaction after OIT has stopped.

If allergen foods need to be avoided or removed from a child’s diet, the child may feel:  

• different or left out because they cannot eat the same food as their friends
• scared from previous allergic reaction experiences
• anxious about having another allergic reaction
• confused about why they cannot eat certain foods  
• self-conscious  
• many other related emotions

While creating a safe environment for children with food allergies, it is important not to create an environment of fear. Care must be taken to make sure a child’s environment has minimal risk of allergen exposure and easy access to emergency treatment if required. These actions can help a child feel safe and confident when eating or being around possible food allergens.   

Food allergy diets can be limiting and may impact a child’s nutrition, growth and mental wellbeing.

Common childhood food allergens including egg, milk, soy, peanuts and wheat are found in many foods. Traces of these foods can regularly be found in other food products because of cross-contamination in processing factories.  It can be difficult and limiting to avoid:

• common allergens
• multiple allergens
• foods that may contain traces of allergens.

It is important, where possible, to include alternative foods from the allergen group to ensure children get all the important vitamins and minerals.  

For example, if a child is unable to have cow's milk, a non-dairy milk alternative may be recommended, such as fortified soy milk, to provide adequate calcium in their diet. Calcium is an important mineral for the development of healthy bones in a growing child. If other sources of food are not included in a child’s diet, it may lead to nutritional deficiencies and poor growth. 

If you suspect your child has poor nutrient intake due to a lack of suitable alternative foods or is experiencing poor growth because of a limited diet, you should consult a paediatric dietitian for help. 

If a child has a food allergy, a lot of time may be spent talking about food, food choices and what the child is eating. Creating normal and relaxed eating environments and habits, even if a child has a restricted diet, can create healthy relationships with food. If children fear mealtimes or are anxious about eating outside of the home, it may lead to negative relationships with food.  This could result in:

• abnormal or disordered eating
• poor body image
• social withdrawal.   

Recent research shows that children who must follow a strict food allergy diet have an increased risk of developing an eating disorder. 

Care must be taken to make sure food preparation areas and the environment children eat are safe. Children often spend a large amount of time at daycare, school or the home. Safety measures should be taken to create and keep safe food environments.

The home

The home is easier to make safe due to parents and carers having greater control of preventative steps such as:

• not bringing or allowing allergen foods into the home where possible
• rules around not sharing foods with siblings who have a food allergy
• family members thoroughly washing their hands before and after eating to reduce the risk of food allergen contact
• educating siblings and other family members on the seriousness of food allergies and where appropriate how to use auto-injector adrenaline pens
• preventing meals and food from being eaten outside the kitchen or dining area to create allergen-free areas
• labelling food products containing food allergens and foods which are safe
• use of different utensils like chopping boards, knives, spoons, bowls and plates to prevent allergen contact
• an at-home First Aid Anaphylaxis Plan for emergencies.

Outside the home

Allergic reactions can occur when a child is not in the home or is not supervised by a parent or carer. It is important for other carers interacting or supervising a child with a food allergy to take proper safety measures.

Parents are carers can take steps to keep children safe when they are not around by educating day-care, school staff, parent-friends, and extended family through:

• written directions to reduce the risk of allergen exposure while they are supervising children
• factsheets with signs and symptoms of an allergic reaction to recognise it early
• sharing the child’s Action Plan for Anaphylaxis and a First Aid Anaphylaxis Plan for emergencies
• explaining and providing instructions on how to use auto-injector adrenaline pens if required.

On-the-go

In other environments, including while travelling on planes or buying and eating out at food places always:

• notify staff if a child has a food allergy
• check all food ingredients thoroughly  
• bring home-prepared safe foods in case there are no suitable food options available
• carry adrenaline auto-injectors and where possible a spare.