Sensitivity or Intolerance versus Allergy

The terms ‘allergy’, ‘intolerance’ and ‘sensitivity’ are very often used interchangeably, which can make understanding the different terms challenging. Whilst sensitivity and intolerance are closer and on occasion can be used interchangeably, allergy cannot and is an entirely different condition. There are differing physiological processes involved, which results in different symptoms and requires different methods of testing. It must be said that sometimes the difference in symptoms can be very subtle, which can lead to further confusion over the condition present.

How we use the terms in our language can also lead to misinterpretation. For example if someone is allergic to a food item they may describe themselves as being ‘sensitive’ to the item, however as a health condition allergy is different from sensitivity or intolerance.

Allergy

An allergic reaction is an inappropriate response produced by the body’s immune system to protect itself to a certain item. The item would ordinarily be thought of as harmless, like food, drink, pollen or medication, however the body has responded as though it is under attack.

After contact with the item allergy symptoms come about very quickly, anything from minutes to 2 hours following exposure. There is also such a thing as delayed or late phase allergic reactions with symptoms occurring up to 6 hours after contact.

On contact with an allergenic item the immune system produces immunoglobulin E (IgE) antibodies, this leads to the release of histamine and other inflammatory cells. It is the histamine, which causes symptoms typical of allergy reactions such as:

  • Rashes, hives, skin changes
  • Itchy mouth, throat
  • Swelling of the lips or face
  • Coughing or sneezing
  • Watery eyes or runny nose
  • Vomiting or diarrhea
  • Worsening of asthma or eczema
  • In rare cases anaphylactic shock

Allergies can occur to all sorts of items; food, drink, pollen, mold, pet dander, insect stings, medications, materials. Common food allergies include items such as wheat, milk, eggs, soya, nuts and shellfish.

Intolerance or Sensitivity

There are a number of different types of sensitivities and intolerances, which again can lead to confusion.

Food sensitivities and intolerances tend to produce symptoms, which are far more digestive system related but can also contribute to symptoms experienced by those with chronic conditions such as irritable bowel syndrome, chronic fatigue, arthritis, autism and ADD/ADHD. Typical symptoms include:

  • Bloating
  • Cramps
  • Flatulence
  • Changes in bowel movements
  • Fatigue
  • Headaches
  • Fogginess

Certain types of food sensitivity or intolerance, which do not involve the lack of a key enzyme, can often be overcome through the implementation of a food elimination diet and/or improving gut health. The period of eliminating foods, which are aggravating symptoms, can allow the digestive system time to ‘rest’. If there is any low level inflammation this period of time also allows the digestive system to settle down and recover. There may be a need to improve gut health and rebalance gut bacteria levels also in this time.

Quick Check

Key differences between allergy aand sensitivity or intolerance…

Allergy, sensitivity and intolerance are different conditions with different physiological processes

Allergy symptoms occur rapidly after contact (up to 2 hours)

Food sensitivity or intolerance symptoms can occur up to 48 hours after ingestion 

Whilst food sensitivity or intolerance may be uncomfortable, annoying or embarrassing it does not have the potential to be serious

Allergy symptoms can be serious and even life-threatening in rare cases

Hair testing does NOT test for allergy