Allergies
The term allergy is often used to describe the body’s unpleasant reaction to a food, insect sting, chemical or other substance that enters the body or touches the skin. The immune system believes these allergens to be damaging and produces IgE antibodies. This leads other blood cells to release further chemicals including histamine which together cause the symptoms of an allergic reaction.
Intolerance
This happens when unpleasant symptoms occur after eating a substance which your body cannot handle because the digestive system does not produce sufficient quantities of a particular enzyme/chemical, which is needed to break down the food and aid digestion.
Chemical Allergies
We are exposed to increasing numbers of chemicals without being aware of the fact as chemicals are in the air that we breathe, both indoors and out; in our food, as colours, flavour enhancers and preservatives; in our drinks, even in our drinking water.
Chemicals are in our workplaces and in our homes, affecting our health, and we can't avoid them, but fortunately most are rendered harmless by our immune systems. Sometimes where the excess is so great, or the chemical so unusual that the body has not yet learned to deal with it and sensitivities develop.
Testing
I use kinesiology (a muscle response test) to enable me to assess whether foods or inhalants are actually causing a problem.