Prevention and treatment of anaphylaxis

Anaphylaxis is a systemic allergic reaction that involves the respiratory and/or cardiovascular systems. Less severe reactions may be defined as anaphylaxis if there is a high index of suspicion for allergic reaction in the setting of previously diagnosed allergy. The prevalence of anaphylaxis is rising at an alarming rate in Westernised societies. The true prevalence of anaphylaxis in childhood is not well documented, but studies from Australia suggest it may be as high as one in 170 among pre-school aged children. Intramuscular adrenaline remains the cornerstone of treatment for the acute episode. Maintaining a supine posture, oxygen and fluid support are important adjunct measures. Whether corticosteroids and antihistamines are beneficial remains inconclusive. Long-term management centres on risk minimisation through prevention of repeat episodes, education of patients/parents in the recognition and emergency treatment of allergic reactions, and optimal management of co-morbidities especially asthma. Identification and avoidance of the allergen trigger are fundamental to prevention. However, avoidance of food triggers is difficult and accidental exposures are common. Education of patients/parents on recognition and treatment of allergic reactions is, therefore, essential and should be supported by provision of an anaphylaxis action plan. An adrenaline auto-injector allows early treatment of anaphylaxis occurring in the community and represents an important aspect of long-term management. However, controversy remains as to who might benefit from carrying this device. Some authoritative bodies recommend selective provision to children identified as being at high risk of anaphylaxis or fatality from anaphylaxis. Whether or not an adrenaline auto-injector is provided, risk minimisation strategies should be implemented for all children with known allergy where ongoing exposure is likely (e.g. food, insect sting).