The difference between a food allergy and a food intollerance?

I know that with an allergy your body releases histimine because the food product you ate is considered a 'foreign' or 'bad' product. (Histimine 1 deals with above the neck, histimine 2 deals with the stomach releasing excess acid)... With food intollerance, what kind of symptoms/signs do you have? Is it just having gas problems?

oh, and with allergies one might have problems with hives, swelling, difficulty breathing, etc

From web MD.

What Is a Food Allergy?
A food allergy is an immune system response. It occurs when the body mistakes an ingredient in food -- usually a protein -- as harmful and creates a defense system (antibodies) to fight it. Allergy symptoms develop when the antibodies are battling the "invading" food. The most common food allergies are peanuts, tree nuts (such as walnuts, pecans and almonds), fish, and shellfish, milk, eggs, soy products, and wheat.

What Is Food Intolerance?
Food intolerance is a digestive system response rather than an immune system response. It occurs when something in a food irritates a person's digestive system or when a person is unable to properly digest or breakdown, the food. Intolerance to lactose, which is found in milk and other dairy products, is the most common food intolerance.

What Are the Symptoms of Food Allergy?
Symptoms of a food allergy can range from mild to severe, and the amount of food necessary to trigger a reaction varies from person to person. Symptoms of food allergy may include:

Rash or hives
Nausea
Stomach pain
Diarrhea
Itchy skin
Shortness of breath
Chest pain
Swelling of the airways to the lungs
Anaphylaxis


What Are the Symptoms of Food Intolerance?
Symptoms of food intolerance include:

Nausea
Stomach pain
Gas, cramps or bloating
Vomiting
Heartburn
Diarrhea
Headaches
Irritability or nervousness

http://www.foodintol.com/allergyorintole...

in my niece's case (she's allergic to milk and dairy products), if you touch after eating cheese she will break out in hives. If she digested something with a hint of milk in it, she would start throwing up and have diarrhea.

allergic = seriously sick, vomitting (from both ends), hives and such

Intollerance = uncomfortable sensation, gas is a big sign.

Food allergy is an exaggerated immune response to dietary proteins. While many people have a food intolerance, food allergies are less common. In a true food allergy, the immune system produces antibodies and histamine in response to the specific food.
Food intolerance or food sensitivity is a negative reaction to a food that may or may not be related to the immune system or to food poisoning. It is caused by the absence of specific chemicals or enzymes needed to digest a food substance.
Please see the web pages for more details on Food allergy and Food intolerance.