Food allergies should not be confused with allergy-like reactions to food (known asfood intoleranceor non-allergic food hypersensitivity).
Examples includelactose intoleranceandsulfite allergy.
Under normal circumstances, your immune system will defend against infectious organisms and other invaders.
Laura Porter / Verywell
It does so by recognizing substances on the surface of a cell known asantigens.
These antibodies will bind the antigen and trigger aninflammatory responseto help neutralize the invader.
With an allergy, the immune system will overreact to an otherwise harmless antigen, referred to as anallergen.
Each key in of IgE the body produces has specific “radar” for each key in of allergen.
Generally speaking, it is protein that acts as the primary food allergen.
Sensitization
The reason why people are allergic to these or any other foods is not entirely clear.
The latter process, calledsensitization, is the mechanism that scientists still don’t fully understand.
Some scientists believe that sensitization is because of the way in which antigens are presented to the immune system.
There, it encounters immune cells, called regulatory T-cells (Tregs), that regulate the immune response.
With regards to food allergies, sensitization typically occurs in the digestive tract.
Atopy
Scientists don’t believe Treg activation is simply a fluke.
Within this population, it is the absence of an immune defense that characterizes the risk.
As contradictory as this may seem, adult-onset food allergies are even more perplexing.
As such, the immune system will see both substances as the same.
Alatex allergyis considered a true allergy because having it increases your risk of a food allergy.
With OAS, the true allergy usually involves tree or grass pollens but may also include aerosolizedmold spores.
This is evidenced in part by the incidence of food allergies in families.
Similar familial links have been seen with seafood and other common food allergies.
Among their many functions, HLA genes are responsible for encoding antigens on the surface of cells.
Errors in the coding may explain why the immune system will suddenly see harmless cells as dangerous.
Although some children “outgrow” their allergies, others may have them for a lifetime.
Shellfish is the most common food allergy in adults, along with tree nuts, peanuts, and fish.
The majority of adults with food allergies had food allergies as children.
For example, if you’re allergic to birch pollen, raw apples might trigger OAS symptoms.
Some can be, and there is no real way to tell who might develop a severe reaction.
This includes a potentially life-threatening, whole-body allergy calledanaphylaxis.
Shellfish is the most common trigger in adults.
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