[Anaphylaxis and anaphylactic shock].

Term anaphylaxis means an immediate hypersensitivity reaction mediated by IgE that produces a clinical syndrome with systemic affection of variable severity. Its prevalence varies according to the habits of each region and of the studied population from 3.2 to 7.6 cases per 100,000 inhabitants per year. Anaphylaxis secondary to the food ingestion accounts for 30-50% of the cases. Some risk factors have been defined, among them the most important are asthma, food allergy and previous reactions to the same food. Biphasic anaphylactic reactions are those presenting a recurrence of anaphylactic symptoms, after the initial remission of them. Success of treatment is based on the early recognition of signs and symptoms and the instauration of treatment with adrenaline.