Primary care management of anaphylaxis

Introduction Anaphylaxis is severe systemic allergic reaction, which is potentially life threatening. It is estimated that there are between 20–30 deaths from anaphylaxis in the UK each year, many of which are potentially preventable.(1) This figure is however likely to represent something of an underestimate because deaths from drug allergy and a proportion of deaths in those with a history of asthma and unexpected deaths may have been misclassified. There are two main mechanisms involved, namely anaphylactic (IgE-mediated) and anaphylactoid (pseudoallergic non IgE-mediated) reactions. In both anaphylactic and anaphylactoid reactions, a very similar clinical picture develops requiring identical immediate management; the precise mechanism involved may however be important in guiding investigations in order to identify possible trigger(s) as IgE-mediated disease is amenable to investigation using skin-prick testing and measurements of serum-specific IgE.(2) Serum tryptase measurements taken during the acute episode can help differentiate between anaphylactic and anaphylactoid reactions and should if possible be taken by the attending GP.