Anaphyllaxis management: Current concepts.

Anaphylactic shock is medical emergency characterized by circulatory collapse resulted from severe acute allergic reactions, namely anaphylaxis and anaphylactoid reaction. Anaphylaxis is an acute, systemic, IgE-mediated, and immediate hypersensitivity reaction caused by the release of mediators by mast cells and basophils after exposure to antigens. The pathophysiology involves activated mast cells and basophils releasing preformed, granule-associated mediators, and newly formed lipid mediators, as well as generating cytokines and chemokines. These cause vasodilatation, increased capillary permeability, and smooth muscle contraction, and attract new cells to the area. Positive feedback mechanisms amplify the reaction, although conversely reactions can self-limit. Anaphylaxis is a clinical diagnosis with a combinations of symptoms and signs that include weakness, dizziness, flushing, angioedema, urticaria of the skin, congestion, and sneezing. More severe symptoms include bronchial constriction, hypotension, vascular collapse associated with angioedema and urticaria, gastrointestinal distress, cardiovascular arrhythmias, and arrest. Prompt administration of epinephrine is critical for the success in the treatment of acute anaphylaxis.