Question

Which of the following is a common treatment for type I hypersensitivity reactions? O Multiple answers: You can select more than one option O A avoid going outdoors B anti-inflammatory steroid treatments o C antihistamine treatments O D anti-Rh IgG injections E desensitizing injections of allergens

Answer 1

Correct options are anti inflammatory steroid treatment, antihistamine treatments and desensitizing injections of allergens.

During type 1 hypersensitive reaction, B cells are activated by Th cells. Antibody release is IgE. Allergens bind to the IgE antibody and it's Fc region is recognised by the Fc recrptor on mast cells and basophils. Mast cells and basophils coated by IgE antibodies are sensitized. They then release histamines, a vasodilator, and heparin, a blood thinner. These cause inflammation at the site as blood flow to the affected tissues is increased. Later exposure to the same allergen cross-links the bound IgE on sensitized cells causes rapid cellular degranulation and liberation of a number of chemical mediators. Reaction of antigen with IgE on mast cells also stimulates synthesis and release of platelet activating factor (PAF), leukotrienes (B4, C4 and D4) and prostaglandins (mainly PGD2).

Desensitizing allergens injections is also given because in many case hyper reaction of immune cells due to antigen may be harmful to own cells. So to lower the immune reaction, desensitizing injection of allergens is given.