Allergy or Intolerance: Disagreeing With Our Food

Food allergies and food intolerances are something that afflicts a significant number of people altering their lifestyles and diets. This edition of the Waiting Room, provided once again by our colleagues at Unified Healthcare Group, describes the differences between the two as well as their prevalence among children and adults. While this may seem a peripheral issue for an adviser it may be less so for an insurer which may consider it as a pre-existing condition.

Reactions to food are common, however most are not due to a true food allergy. Reactions to food are best divided into two categories: 1) those caused by food allergy and 2) all other reactions. It is important to differentiate between the two because the management of each is different.

  • Food allergies develop when the body’s immune system has an abnormal reaction to one or more proteins in a food. Food allergies can lead to serious or even life-threatening allergic reactions.
  • Other food reactions (including food intolerance) are far more common and are not caused by the immune system. Examples include: lactose intolerance, heartburn (gastro-esophageal reflux), bacterial food poisoning and sensitivity to caffeine, to name a few.


Some differences between food allergy and food intolerance

Food Allergy Food Intolerance
  • Immune system reaction
  • In some cases can cause life-threatening anaphylaxis
  • Can show up on allergy tests (i.e. skin tests or blood tests)
  • Often occurs to trace amounts of food (complete exclusion of the food is essential)
  • Typically occurs quickly, within minutes to two hours after eating
  • Not an immune response
  • Cannot be life threatening (however can have significant impact on lifestyle)
  • Does not show up on allergy tests
  • Can occur after ingesting small amounts of a culprit food but is typically triggered by consuming larger amounts
  • Typically slower onset of symptoms and may be delayed by many hours. The symptoms may also last for several hours, even into the next day and sometimes longer


The most common foods causing adverse reactions include cow’s milk, fruits (especially citrus and strawberry), and vegetables (especially tomato), accounting for up to two-thirds of reported cases.

A true food allergy most often begins in the first two years of life. Certain food allergies, such as those to cow’s milk and hen’s egg, are usually outgrown during childhood or adolescence, whereas peanut and tree nut allergies are more likely to persist into adulthood.

Classic Food Allergy

In people with “classic” food allergies, allergic antibodies, called immunoglobulin E (IgE), develop in response to proteins in certain foods. When the person is exposed to that protein at a later time (eg, by eating peanuts), binding of the food protein to IgE triggers a release of chemicals, which cause the symptoms of an allergic reaction. This typically occurs quickly, within minutes to two hours after eating.

Sudden-onset symptoms

The symptoms of a food allergy can vary from mild to severe or even life threatening. It is not always possible to predict how severe symptoms will be based upon the symptoms experienced during a previous reaction. As an example, a person could have mild hives after eating peanuts on one occasion and then have an anaphylactic reaction after eating peanuts another time. However, reactions are not necessarily worse after each exposure.

The most common sudden-onset symptoms of food allergy include:

  • Skin – Itching, flushing, hives (urticaria, like mosquito bites), or swelling (angioedema)
  • Eyes – Itching, tearing, redness, or swelling of the skin around the eyes
  • Nose and mouth – Sneezing, runny nose, nasal congestion, swelling of the tongue, or a metallic taste
  • Lungs and throat – Difficulty getting air in or out, repeated coughing, chest tightness, wheezing or other sounds of laboured breathing, increased mucus production, throat swelling or itching, hoarseness, change in voice, or a sensation of choking
  • Heart and circulation – Dizziness, weakness, fainting, rapid, slow, or irregular heart rate, or low blood pressure
  • Digestive system – Nausea, vomiting, abdominal cramps, or diarrhoea
  • Nervous system – Anxiety, confusion, or a sense of impending doom


Anaphylaxis is the most serious type of allergic reaction and can cause life-threatening signs and symptoms, including difficulty breathing, swelling of the upper throat and/or tongue, a very rapid or irregular heartbeat, low blood pressure, or cardiac arrest (the heart stops beating). Anaphylaxis generally begins within 5 to 60 minutes of exposure to a trigger, although rarely symptoms can begin several hours after eating. A person who develops symptoms of anaphylaxis must be treated immediately with an injection of adrenaline. An adrenaline auto-injector (EpiPen) will be prescribed so that the person can administer his or her own adrenaline in the case of future anaphylactic episodes.

Many different foods can potentially trigger anaphylaxis. In adults, peanuts, tree nuts (e.g. walnuts), fish and shellfish are common causes of anaphylactic reactions. In children, peanuts and tree nuts are the most common.


Anyone with signs or symptoms of a food allergy should see their healthcare provider. Between 20 and 30% of people report food allergy in themselves or their children. However, only 6 to 8% of children under the age of five and 3 to 4% of adults have a true food allergy.

Blood and/or skin testing is often used to confirm the food allergy and determine if avoidance of a particular food is necessary.

Allergy testing

Testing for food allergies often includes skin testing and/or blood tests. Depending upon the situation, tests may be done to determine if a person is allergic to pollens, insects, latex and other allergens. However, testing is only recommended if the person is suspected to have an allergy. As an example, if a person had a reaction after eating peanuts, but has never reacted to wheat or eggs and eats them regularly, it is not necessary to test for allergy to wheat or eggs.

Skin testing: Skin testing involves pricking/scratching the skin with a tiny probe that is coated with food extract or fresh food. The pricks are usually done on the forearm or upper back after the skin is cleaned with alcohol. The skin prick is not usually painful.

Adults and children of any age may have skin testing. The test may result in small hives (like a mosquito bite) at the site of the prick/scratch. Only a trained healthcare provider, usually an allergy specialist, should do skin testing. This specialist will evaluate the size of the test results to assist in making a diagnosis.

Blood tests: Blood tests are available to assist doctors in making a diagnosis. Neither the skin test nor the blood test can be depended upon to make a diagnosis without a clinician considering the medical history and other supporting information. Blood tests are widely available and do not require an allergy specialist to perform the test. However, consultation with an allergy specialist may be recommended to interpret the results of the test.

Elimination diets: An elimination diet is a specially designed diet that eliminates one or more foods or groups of food from a person’s diet for a period of time. The food is then added back to determine if signs or symptoms of a food allergy develop.

An elimination diet may be recommended as part of the process of determining if a person has food allergies. An allergist or dietician must be involved in designing an elimination diet because avoiding entire groups of foods (e.g. milk) could potentially lead to malnutrition, especially in infants and children. An elimination diet by itself does not often lead to the diagnosis of food allergy.

When to Seek Help

It is sometimes difficult to know if a reaction is caused by true food allergy or food intolerance. Anyone who has one or more of the following symptoms after eating should seek medical care:

  • Nausea or vomiting
  • Cramping, abdominal pain or diarrhoea, especially if there is blood or mucus in the stool
  • Itching or raised red welts on the skin
  • Flushed (reddened, warm) skin
  • Swelling of the lips, mouth, face, or throat
  • Wheezing, coughing, or difficulty breathing
  • Light-headedness or passing out

The Importance of Awareness For Advisers

Anyone with school aged children would be well aware of the safety messages around food allergies to prevent their own children or others from being exposed to anything that may cause an allergic reaction.

However, financial advisers should also be speaking with their clients on this issue and checking whether it should be disclosed as a pre-existing condition within income protection and life insurance policies.

It may sound trivial but no-one would like a client to be denied a claim because they ate the wrong food.  Thankfully tests for these conditions are simple and a little knowledge can go a long way in securing the life and lifestyle of a client.


Burks, W. Patient information: Food allergy symptoms and diagnosis (Beyond the Basics). Up To Date. 2015. Accessed at:


The Waiting Room looks at of some of the common medical conditions which advisers may come across when dealing with clients.

Unified Healthcare Group serves Australia’s financial services industry by providing a one-stop solution for all medical requirements associated with life insurance claims and underwriting.

This article was written by Unified Healthcare Group National Medical Advisor, Dr Stephen Simonds

Contact or follow the author: Telephone: 1300 558 583 | Website | Email | LinkedIn

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