25 August 2003
EPIPEN USE: GOOD CLINICAL PRACTICE
Dr Gold in commenting on my paper on suggestions for rational prescribing of EpiPens in childhood food allergy1 questions the appropriateness of mortality statistics in the discussion of possible risks and benefits of EpiPen prescription. He concludes that morbidity is also a valid measure and states that EpiPen use is associated with a decrease in anaphylaxis morbidity and that additional factors such as the impact of EpiPen prescription on the quality of life should be reviewed2. The evidence that he quotes for reduction in morbidity is derived from his own important study, which documented a widespread failure to use EpiPen appropriately. In this study morbidity is defined as either admission to hospital or subsequently administrated adrenaline3. It is not surprising that subsequent administration of adrenaline is greater in individuals in whom an EpiPen was not used initially although whether this should be classified as an increase in morbidity is uncertain. It is unclear in the quoted reference what is meant by hospital admission. If children who did not use an EpiPen initially attend a hospital for administration of adrenaline, is this counted as a hospital admission? In addition, The American Academy of Asthma, Allergy and Immunology position statement on the treatment of anaphylaxis in schools and other childcare settings states ‘all individuals receiving emergency epinephrine should immediately be transported to a hospital even if the symptoms appear to have resolved’4. The current anaphylaxis action plan developed by the Australian Society of Clinical Immunology and Allergy states that ‘when an EpiPen is given, an ambulance should be called’ presumably again to transport the patient to hospital for observation. If these guidelines are followed it is therefore not clear that use of EpiPen will actually alter the rate of hospital attendance.
Dr Gold also implies that provision of an EpiPen will improve the quality of life of the child and family. Again this is open to question. The only published study that I am aware of was in patients with stinging insect sensitivity in whom management was randomized to provision of an EpiPen or venom immunotherapy. Whilst the quality of life improved in those patients having immunotherapy, it actually deteriorated significantly in those provided with an EpiPen alone5. The reasons were unclear although the authors suggested that provision of the EpiPen ‘may act as an affirmation and reminder of the patient's risk and thus, negatively influence health-related quality of life’. In the eminently desirable aim of providing Epipens to patients at significant risk of anaphylaxis it is also important to remember that this is not a measure without impact on the life of the child and the family and that if EpiPens are prescribed inappropriately there is the potential for creating a situation of anaphylaxis anxiety in individuals with minimal risk of having a subsequent significant reaction. It is for these reasons that discussion of criteria and guidelines for prescribing are particularly important. Mortality is at least a definite endpoint and therefore, I believe its use is valid in the discussion of EpiPen use. The appropriate use of adrenaline in anaphylaxis can be lifesaving, however, I would maintain that the assumptions that provision of an EpiPen will either reduce morbidity or improve quality of life remain unproven assertions that require further research.
The views expressed by Dr MS Gold in his commentary on the article by Professor Kemp were an individual opinion and not the official position of the Anaphylaxis Working Party of the Australasian Society of Clinical Immunology and Allergy.