Rast and Eucast in Blood Test- A Review

Abstract

An allergic response is the hypersensitive immune response to a substance which is normally harmless or
would not cause an immune response in everyone. An allergic response can cause several symptoms such as
itching, inflammation and tissue injury. The manifestation of allergies is recognized in the form of urticaria,
swelling, burning, pain, and dryness of the mucosa, stomatitis. radioallergosorbent test (RAST) which is the
radioallergosorbent test used for the confirmation of allergic reaction in the body. This test specifically deals
with the IgE antibodies which are responsible for the allergic reactions on the body. It is very essential to crosscheck the exact history related to allergy. Individual sensitivity and population sensitivity, both are equally
responsible for skin allergy are the factors which are to be considered. Skin tests become negative under
conditions of severe allergic reactions which is determined by graded therapy by freedom from contact and
using epinephrine administration. RAST test is a two-stage procedure. RAST- test is performed according
to the guidelines of European Committee on Antimicrobial Susceptibility (EUCAST). The reliability of
the test is high compared to other skin tests. Specificity based on two radioallergosorbent tests is high as
90% for inhaled allergens. It shows excellent reproducibility across a full measuring range with the help
of the calibration curve. The RAST test is considered to be extremely sensitive. It shows high specificity
which binds to allergen-specific IgE. This article mainly deals with the RAST procedure, advantages and
disadvantages of the test.