Anaphylactic shock: pathogenesis, etiology and examples

Anaphylactic shock

1. Anaphylactic Shock Definition- It is fatal clinical manifestation of type I hypersensitivity reaction. It is an allergic reaction which is rarely seen in few allergic individuals . Principal mechanism -Acute widespread systemic vasodilation and increased vascular permeability results in tissue hypoperfusion and hypoxia . Immunoglobin involved- IgE . Principal mediators - Histamine , enzymes (proteases), prostaglandins - D2, leukotrienes (B4, C4, D4), cytokines . The flood of the above chemicals causes the body to go into shock.

2. Type I hypersensitivity

3. within minutes after exposure due to contraction of respiratory bronchioles due to release of histamines- seen after 30 mins to 1 hour due to vasodilatation-sudden onset If these symptoms are not treated , it may lead to the death of an individual within an hour .

4. Common triggers Antibiotics -Penicillin, amoxycillin, aspirin Bee stings Insect bite General anaesthetics - neuromuscular blockers, opoids. Foreign proteins -Antisera Foods - Peanuts, milk, fish and shellfish Food additives - colorants (tartazine, carmine), preservatives (sodium benzoate), thickeners ( gum arabic).