What is the difference between allergy and intolerance?

The immune response. An allergy is caused by specific cells and/or proteins in the body that are designed to recognize specific sites in the allergen, i.e. Peanut, walnut, cat dander, etc. These include immunoglobulin e, and t and b cells. An intolerance is caused by an inability to digest a sugar or protein, but does not involve the same immunoglobulins and cells.
Totally different. An allergy results in a complex process in which subtypes of wbcs called eosinophils, mast cells, & basophils may be activated. This may lead to release of histamine (hence anti-histamine drugs). But you will get an increase in ige (a type of antibody) that triggers chemical release from these cells. Intolerance is a bad reaction to something (like vomiting). No ige or histamine release occurs.
Complicated. An allergy is an immune response. There are many patients who have non-allergic rhinitis symptoms which can mimic allergy but are triggered by irritants such as odors, weather changes, viruses or dust irritants.
They are different . Allergy is an altered response by your immune system to an allergen. Allergens are usually harmless particles like pollens, dust, cat dander or even certain foods, wherein your body has antibodies that fight them releasing chemicals to get rid of them. Intolerance is where your body is not able to process certain proteins like milk protein or gluten. One good example would be lactose intolerance.

Related Questions

I want to know what is the difference between food allergy and intolerance?

IgE vs non-IgE. True food allergy is mediated by the ige antibody and can be tested for by skin testing or blood ige. Symptoms can be severe and only a small amount needed to cause a reaction. Intolerance are almost always GI symptoms (pain, diarrhea, etc) and have negative ige blood and skin tests. Small amounts of food may be tolerated but a "threshold dose" above which symptoms will occur. Read more...

What's the difference between a food allergy and intolerance?

Allergy antibody. Food allergy is an allergy antibody, ige, mediated reaction to a particular food that results in allergic reaction. Food intolerance is a "junk term" that includes would describe any reaction except food allergy. It is not very specific. Read more...
Intolerance subset. Food allergy (fa) is a subset of food intolerance (fi). Fa involves an abnormal immune system reaction to an otherwise innocuous food. Mechanisms of fi include inability to digest a food as in lactose intolerance. Fa can be life-threatening; fi is not. Symptoms of fi are limited to the GI tract - pain, bloat, gas, vomiting, diarrhea. Fa symptoms may be GI as well as respiratory, skin & cardiac. Read more...

What's the difference between food allergy and food intolerance?

Mechanism. Food allergies are mediated by the ige antibody and it takes only a small amount to lead to a severe even anaphylactic allergic reaction and rarely death. Food intolerance is GI symptoms of bloating, gassy, crampy belly pain and diarrhea after eating usually larger amounts of a food. Intolerances are more common (like lactose intolerance) and are not mediated by ige antibody and not life ending. Read more...