the low down on food allergies

The Basics

A food allergy is an immune system response to a food protein that the body mistakenly believes is harmful.  When the individual eats food containing that protein, the immune system releases large amounts of chemicals, triggering symptoms that can affect a person’s breathing, gastrointestinal tract, skin and/or heart.  Some food allergies can be severe and unpredictable, causing potentially life threatening reactions known as anaphylaxis.

Food allergies affect up to 8% of infants and about 2% of adults.  Fortunately the majority of children will outgrow their allergy.  There are more than 170 foods known to have triggered severe allergic reactions, the most common allergens in childhood being egg, milk, peanut and tree nuts.  Other common triggers include fish, shellfish, sesame, soya and wheat.

Currently, until there is a cure for food allergy, avoidance of the food is the only way to prevent a reaction.  In milder cases, oral antihistamines can be used to treat the symptoms.  In cases where an allergic reaction is severe, adrenaline is the first line treatment and can be administered via an auto-injector, e.g. EpiPen®


How to recognize an allergic reaction

Mild to moderate allergic reactions:

  • Hives, welts or body redness
  • Swelling of the face, lips, eyes
  • Vomiting, diarrhea or abdominal pain
  • tingling of the mouth
  • Severe allergic reaction- ANAPHYLAXIS

Anaphylaxis is the most severe form of allergic reaction and is potentially life threatening.  It must be treated as a medical emergency, requiring immediate medical attention.  Anaphylaxis is a generalised allergic reaction, which often involves more than one body system (e.g. respiratory, gastro-intestinal and cardiovascular).  A severe allergic reaction or anaphylaxis usually occurs within 20 minutes to 2 hours of exposure to the allergen and can rapidly become life threatening.

Signs of anaphylaxis:

  • Difficult/noisy breathing
  • Swelling of the tongue
  • Swelling or tightness in the throat
  • Difficulty talking and/or hoarse voice
  • Wheeze or persistent cough
  • Persistent dizziness or collapse
  • Pale and floppy (in young children)
  • Common causes of anaphylaxis:


Milk, eggs, peanuts, tree nuts, sesame, fish, shellfish, wheat and soy are the most common food triggers, which cause 90 percent of allergic reactions; however, any food can trigger anaphylaxis. In some sensitive individuals, reactions may occur to trace amounts, the smell of particular foods being cooked (e.g. fish) or even kissing someone who has eaten the food they’re allergic to.

Bites and Stings

Bee or wasp stings are the most common triggers of anaphylaxis to insect stings.


Medications, both over the counter and prescribed, can cause life threatening allergic reactions.  Individuals can also have anaphylactic reactions to herbal or ‘alternative’ medicines.

Other triggers such as latex or exercise induced anaphylaxis are less common.

If you suspect a food has caused a reaction, avoid that food, seek medical advice and have it investigated.  If you are worried about a serious reaction call an ambulance.  If you know you have a food allergy, then always avoid that specific food trigger.  Always have your emergency medication close by as accidental exposures do happen.  Communicate to those around you about allergies – what to look out for regarding symptoms, what to avoid and how to initiate treatment.  Spread the word……..Allergy Awareness saves lives.

Article by Paediatric Dietitian Lindsay Archibald-Durham