I had pretty much the same question and someone posted this for me, hope it helps a little
What is the difference between food allergy and food intolerance?
Many people think the terms food allergy and food intolerance mean the same thing; however, they do not. A food intolerance is an adverse food-induced reaction that does not involve the immune system. Lactose intolerance is one example of a food intolerance. A person with lactose intolerance lacks an enzyme that is needed to digest milk sugar. When the person eats milk products, symptoms such as gas, bloating, and abdominal pain may occur.
A food allergy occurs when the immune system reacts to a certain food. The most common form of an immune system reaction occurs when the body creates immunoglobulin E (IgE) antibodies to the food. When these IgE antibodies react with the food, histamine and other chemicals (called mediators) cause hives, asthma, or other symptoms of an allergic reaction.
Introduction
Foods can cause a number of reactions, not all of which are allergic. Anyone can experience an adverse reaction to a food. The types of adverse reactions are as follows:
Adverse Reactions to Foods
Food Intolerance - where the immune system is not involved in the reaction
* Food poisoning
* Idiosyncratic reactions to food
* Anaphylactoid reactions (they act like anaphylaxis but there is no allergy-IgE antibody involved)
* Pharmacologic reactions
Food Allergy - when the immune system is involved in the reaction
* IgE mediated (classic allergy- tests are available) Non-IgE mediated
* Type III immune response- a serum sickness like reaction
* Type IV immune response- a contact dermatitis type reaction
Food Allergy- Facts and Figures
Food intolerance accounts for 80% of all adverse reactions to food.
Food allergy accounts for 20% of all adverse reactions to food.
Allergic reactions can be itching, swelling, rash, spreading hives, vomiting, diarrhea, breathing difficulties and in the most severe of the allergic disorders, anaphylaxis can lead to collapse and death. By definition, anaphylaxis is an allergic reaction which involves two of the body's systems (eg respiratory and gastrointestinal or skin). Anaphylactic deaths as a result of insect bites or penicillin are usually very quick - within minutes - and due to cardiac arrest, anaphylactic deaths due to food allergies are usually due to suffocation (breathing difficulties).
Food intolerance reactions can be the same as above, as well as:
skin (rashes, swelling)
airways (asthma, stuffy or runny nose, frequent colds and infections)
gastrointestinal tract (irritable bowel symptoms, colic, bloating, diarrhea, vomiting, frequent mouth ulcers, reflux, bedwetting, 'sneaky poos', 'sticky poos')
central nervous system (migraines, headaches, anxiety, depression, lethargy, impairment of memory and concentration, panic attacks, irritability, restlessness, inattention, sleep disturbance, restless legs, moodswings, PMT).
Symptoms of food intolerance can come and go and change throughout life.