what is the difference between intolerance and allergy ?

Question

Is there any point in which intolerance to a certain food (say milk or eggs for example) turns into an allergy or are they totally unrelated ?

Is intolerance showing up only as digestion problems and not other allergy symptoms ?

Can you mistakenly interrpret intolerance as allegry in blood tests or vica versa ?

Answer 1

An intolerance would not show up as an allergy in blood tests.

here's info from webmd.com


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
How Common Are Food Allergies and Intolerances?
Food allergies affect about 2 to 4% of adults and 6 to 8% of children. Food intolerances are much more common. In fact, nearly everyone at one time has had an unpleasant reaction to something they ate. Some people have specific food intolerances. Lactose intolerance, the most common food intolerance, affects about 10% of Americans.

What Causes Food Allergies and Intolerances?
Food allergies arise from sensitivity to chemical compounds (proteins) in food. They develop after you are exposed to a food protein that your body thinks is harmful. The first time you eat the food containing the protein, your immune system responds by creating specific disease-fighting antibodies (called immunoglobulin E or IgE). When you eat the food again, it triggers the release of IgE antibodies and other chemicals, including histamine, in an effort to expel the protein "invader" from your body. Histamine is a powerful chemical that can affect the respiratory system, gastrointestinal tract, skin or cardiovascular system.

As a result of this response, allergy symptoms occur. The allergy symptoms you have depend on where in the body the histamine is released. If it is released in the ears, nose and throat, you may have an itchy nose and mouth, or trouble breathing or swallowing. If histamine is released in the skin, you may develop hives or a rash. If histamine is released in the gastrointestinal tract, you likely will develop stomach pains, cramps or diarrhea. Many people experience a combination of symptoms as the food is eaten and digested.

Food allergies often run in families, suggesting that the condition can be inherited.

There are many factors that may contribute to food intolerance. In some cases, as with lactose intolerance, the person lacks the chemicals, called enzymes, necessary to properly digest certain proteins found in food. Also common are intolerances to some chemical ingredients added to food to provide color, enhance taste and protect against the growth of bacteria. These ingredients include various dyes and monosodium glutamate (MSG), a flavor enhancer.

Substances called sulfites are also a source of intolerance for some people. They may occur naturally, as in red wines or may be added to prevent the growth of mold.

Salicylates are a group of plant chemicals found naturally in many fruits, vegetables, nuts, coffee, juices, beer and wine. Aspirin also is a compound of the salicylate family. Foods containing salicylates may trigger symptoms in people who are sensitive to aspirin. Of course, any food consumed in excessive quantities can cause digestive symptoms.

Answer 2

Intolerance expresses itself as allergies. I think they are same or similar. I have many food intolerances. They don't show up as allergies in the sense of causing any rash or itching, sneezing etc. but cause release of histamine in the stomach causing acidity.

Answer 3

there is not a large difference between the two, it is how they would show up on tests