Food Intolerance vs Food Allergy

Bad reactions to food can be due to immune-mediated ‘allergic reactions’ or ‘food intolerances’ . These are two distinctly different things. Both of these things can be very uncomfortable and lead to significant dysfunction in peoples lives. Food allergy and food intolerance are diagnosed and treated differently.

Food Intolerances

Food intolerances are due to difficulty digesting or metabolising a particular food. Intolerances lead to gut inflammation, with symptoms including nausea, diarrhoea, bloating and abdominal cramping. Food intolerances are best diagnosed by exclusion diets and/or challenge testing. Many people exclude foods if they cause discomfort, however excluding a whole food group can have a significant impact on you. It is best to do an exclusion diet in consultation with an expert. That way you are more likely to accurately diagnose food intolerance and minimise the risk of excluding nutrient-rich foods unneccessarily.

Food intolerances can’t be diagnosed by skin prick testing. Histamine intolerance and lactose intolerance cannot be diagnosed by skin prick testing.

Food Allergy

Food allergy is caused by an abnormal immune system response to food, causing immunes cells to release histamine and other chemical mediators. This can lead to symptoms involving skin (hives/urticaria), gastrointestinal system (nausea, cramping, diarrhoea), oropharynx (itchy mouth and lips), respiratory tract symptoms (rhinoconjunctivitis) and anaphylaxis.

Food allergy can be testing for with skin prick testing and/or blood testing, howeverthis type of allergic response is more complex than other allergy types. Many people have positive skin prick testing, without symptoms of allergy to a particular food allergen.

If you think you have a food allergy, it is best to book an appointment to discuss symptoms, diagnosis and potential treatments.

The approach to food intolerances/allergy is:

  1. Discuss symptoms with doctor to establish likelihood of allergy versus intolerance

  2. Develop management plan for intolerance, involving exclusion diet

  3. Undertake skin prick or blood testing if indicated

  4. Develop plan for food avoidance with Dietitian

  5. Consider, prescribe and educate regarding adrenaline auto-injector if indicated.