b'AnaphylaxisChapterAnaphylaxis is a form of shock that develops from the most serious type of allergic reaction. It is severe and potentially life threatening, symptoms can start within 20 minutes of exposure and can progress rapidly.Anaphylaxis should be treated as a medical emergency requiring immediate treatment.The allergic reaction can produce such severe swelling of the air passages that suffocation and death may occur within a few minutes. Peanuts, tree nuts, eggs, shellfish, milk, soy, wheat, sesame and fish are the most common food allergens, which cause 90% of allergic reactions tofoods. It can also occur as a result of sensitivity to insect stings (bees), medicines, drugs (penicillin) and latex. People with allergies, asthma and eczema may be at increased risk of developing an anaphylactic reaction.It is important that people at risk of anaphylaxis have well managed asthma.Anaphylaxis is a generalised severe allergic reaction that: Has signs and/or symptoms that indicate the respiratory (breathing) or cardiovascular systems (heart and blood pressure) have been affected. When anaphylaxis occurs, chemicals are released into the blood that dilate blood vessels and constrict air passages. Blood pressure falls and the throat may swell resulting in serious airway and breathing difficulties.Usually occurs within 20 minutes to 2 hours after exposure to the allergen trigger. Usually involves more than one body system such as the skin and lungs.Can progress rapidly.Despite common beliefs, anaphylaxis related deaths are quite rare. In Australia, approximately 10 people a year die from anaphylaxis, most commonly after exposure to medication or blood transfusions, sometimes to insect stings and rarely to food.An individual who is diagnosed with a severe allergy and isat risk of anaphylaxis, often has an adrenaline auto injector prescribed. This adrenaline auto injector isrecognised as first line treatment in an emergency.184 Medical Emergencies'