Who needs adrenaline?
Allergic reactions vary in severity.
In its 2014 guidelines, the European Academy of Allergy and Clinical Immunology suggests the following:
Absolute indications for adrenaline auto-injector:
- Previous anaphylaxis triggered by food, latex, or aeroallergens
- Previous exercise-induced anaphylaxis
- Previous idiopathic anaphylaxis
- Co-existing unstable or moderate to severe, persistent asthma and a food allergy*
- Venom allergy in adults with previous systemic reactions (not receiving maintenance VIT) and children with more than cutaneous/mucosal systemic reactions
- Underlying mast cell disorders or elevated baseline serum tryptase concentrations together with any previous systemic allergic reactions to insect stings, even in VIT-treated patients
Consider prescribing adrenaline auto-injector with any of the following additional factors (especially if more than one is present)
- Previous mild-to-moderate allergic reaction* to peanut and/or tree nut
- Teenager or young adult with a food allergy*
- Remote from medical help and previous mild-to-moderate allergic reaction to a food, venom, Latex, or aeroallergens
- Previous mild-to-moderate allergic reaction to traces of food*
Notes *Excluding pollen food syndrome (oral allergy syndrome).
Muraro,A. et al. (2014) “Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology”. Allergy 69 (7) online early view article.
The decision to prescribe adrenaline should be part of an approach that includes a thorough assessment of the patient. This can ideally be done at a specialist allergy clinic or by a doctor who has had training in allergy management.
When and how to use adrenaline
The varied and unpredictable course of severe allergic reactions makes it difficult to define when adrenaline is best administered. The UK Resuscitation Council recommends giving adrenaline as soon as there is stridor, respiratory distress, wheeze or clinical signs or shock. Urgent transfer to hospital is vital. Visit their site.
How many devices to prescribe
The UK’s Medicines and Healthcare Products Regulatory Agency (MHRA) advised in June 2014 that anyone
who is at risk of suffering anaphylaxis should always have two adrenaline injector devices immediately
available for use (MHRA, 2014). The MHRA report said: “It is acknowledged that in some cases, a single
injection is not sufficient to achieve a response for a number of reasons, including severity of attack as well as the possibility that a dose has not been effectively administered; a second injection may therefore be needed.” The Anaphylaxis Campaign supports this view.
In cases where the risk of anaphylaxis is thought to be low, there is a difference of opinion among members of the medical community. While some doctors agree that two injectors must always be immediately available (in line with the MHRA report), others believe it is sufficient to have one device available, arguing that one injection is likely to be enough to treat the symptoms until emergency medical help arrives.
This is a matter that you should discuss thoroughly with your patient. Advice for patients from the MHRA on the use of adrenaline auto-injectors can be found here.
Reference: Adrenaline auto-injectors: a review of clinical and quality considerations, MHRA, 04 June 2014.