Type I food allergy mechanism

Four distinct types of hypersensitive reactions – types I, II, III, IV are recognized and each type involves different components of the immune system.

What is type I allergies?
This type of allergies is also known as food anaphylaxis. The Greek word anaphylaxis and refers to allergic reactions to foreign protein molecules.

These reactions are the most frequent, the best known and the easiest to diagnose. They occurred when an individual is already sensitized.

Immediate hypersensitivity type allergic reactions appear to fall entirely within the category. Type I reactions usually occur within a few minutes to several hours after consumption of the offending food. It is the common allergy that can largely be attributed to IgE and a sub-population of immune cells, the mast cells and basophilis.

IgE antibodies will bind the allergen and this will lead to mast-cell degranulations and release of mediators such as histamine and the characteristic features of allergy include:
*urticaria
*angioedema
*hypotension
*anaphylaxis

Immediate type allergy is usually obvious to everyone who suffers from it and afflicts about 10% of the population. The immediate or type 1 food allergy pattern is easily recognized because it involves quick and dramatics symptoms.

Patients who tend to have type 1 reactions are easily identified by their history; they tend to have hay fever, asthma and eczema as do family members. These triads of allergic manifestations had been called ‘atopy’.
Type I food allergy mechanism