Anaphylaxis can be defined as a severe, generalised and multi-organ reaction (Grabenhenrich et al, 2016; Anagnostou and Turner, 2019). It is at the extreme end of the allergic spectrum and significant symptoms include: rapidly developing life-threatening airway, breathing and/or circulation problems (Grabenhenrich et al, 2016; Anaphylaxis Campaign, 2019). Frequently, these symptoms are connected with skin and mucosal changes. (See Box 1 for other common symptoms).
The presentation of signs and symptoms can vary greatly between individuals. There is a vast number of triggers that can cause anaphylaxis although those most commonly identified in Europe include food, drugs and venom (Grabenhenrich et al, 2016). Food is a particularly common trigger for children and young people (National Institute for Health and Care Excellence (NICE), 2011a).
Causes and symptoms
The incidence of anaphylaxis globally varies greatly (Wang et al, 2019). However, between 3.5% and 8% of children are thought to have food allergies (Foong et al, 2017). A study found that in England and Wales between 1992 and 2012 there was a 615% increase in hospital admissions due to anaphylaxis (Turner et al, 2015). Although deaths due to anaphylaxis were not found to have increased, it is estimated that across the whole population there are around 20 allergy-related deaths each year in the UK (Resuscitation Council, 2012). It is thought that the rise in admissions may be due to increasing public awareness, shifting patterns in public behaviours and changing responses by health care providers (Turner et al, 2015).
Commonly recognised triggers include:
In approximately 20% of anaphylactic reactions the cause remains unknown, described as idiopathic (Anagnostou and Turner, 2019).
The significant symptoms are caused by the body's physiological response to a perceived threat, known as a trigger or an allergen. The body releases numerous compounds in response to the trigger, including histamine, which in turn produces an effect. Some examples of the physiological effects include capillary leakage, which causes the recognisable urticarial rash (Figure 1) and hypotension. Mucosal oedema, which is the build-up of fluid in the layer of tissue that lines the body's interior, leads to swelling around the airways. Smooth muscle contraction can cause asthma-like symptoms and abdominal pain (Jevon, 2008). Severe clinical risks include asphyxia, respiratory arrest and circulatory collapse.
Anaphylaxis can vary in severity of outcome and symptoms, however, the onset is usually rapid (between 1 minute and 3 hours following exposure to a trigger). The lack of a consistent presentation can lead to challenges for accurate diagnosis (Jevon, 2008). Differential diagnoses include a panic attack, vasovagal faint or commonly in children an asthma attack. A detailed history and assessment following the ‘ABCDE approach’ would be required. A nurse should also observe for the symptoms in Box 1 as recommended by the Resuscitation Council UK (2012).
Management
Management will vary depending on the setting, location, and staffing or resources available. No matter the setting, a nurse should call for additional help in the form of an ambulance or doctor early. As with any clinical emergency a practitioner should treat the greatest threat to life first, using the ABCDE approach (see Box 2).
Adrenaline, in some countries known as epinephrine, is the most important intervention in treating anaphylaxis (Anagnostou and Turner, 2019). This is given as an intramuscular injection (often in autoinjector form) and should be administered as soon as any symptoms are present. If in a community setting an ambulance must be called immediately following an injection of adrenaline, even if there is an improvement in the presenting symptoms. Adrenaline acts quickly to open up the airways, reduces swelling and raises blood pressure. It has both α-sympathomimetic and β-sympathomimetic actions resulting in peripheral vasoconstriction, increased cardiac output and bronchodilation (Anagnostou and Turner, 2019). Studies have shown that it is the only drug that inhibits the further release of inflammatory mediators from mast cells and basophils (Anagnostou and Turner, 2019). It is difficult to prove categorically that adrenaline saves lives and studying severe reactions in research is difficult because of the speed with which anaphylaxis can occur (Sheikh et al, 2008). Nevertheless, prescribing and administering adrenaline efficiently is a key component in national guidance and policy (NICE, 2011b).
In around 1 in 20 cases, a second ‘wave’ of symptoms can develop. This is referred to as a biphasic reaction. Around half of biphasic reactions occur within 6-12 hours of the initial reaction (Lee et al, 2015). Therefore, the length of observation in hospital should be determined by the treating doctor. Sometimes monitoring for 8-24 hours will be required. A lengthy observation period is particularly necessary when the reaction is severe, is of slow onset or idiopathic or could be triggered if further absorption of the allergen is possible (Jevon, 2008). Patients with severe asthma also tend to remain under observation in hospital for a longer period (Jevon, 2008). Children with asthmas tend to be at greater risk of anaphylaxis and deterioration because their existing condition means their airways are already prone to inflammation (Jevon, 2008). Both asthma and allergy are categorised as atopic diseases. Research has shown that having one atopic disease can predispose someone to having another.
A nurse must recognise the need to manage anaphylaxis after the emergency event has been treated. This should include a referral to a specialist allergy or immunology team (Royal College of Paediatrics and Child Health (RCPCH), 2011). A specialist team will usually see clients who have experienced anaphylaxis after the event in order to ensure accurate diagnosis, identify the cause, establish a prognosis and help to prevent further episodes (Webb and Lieberman, 2006).
It is recommended that a management plan is created so that not only family members but also any care setting or school staff are aware of the condition to ensure recognition and management (RCPCH, 2011). The British Society for Allergy and Clinical Immunology (BSACI) has created standardised care plan templates, which are free to download (BSACI, 2018). Written in conjunction with RCPCH and other charitable organisations these robust care plans support the child or young person and all those who care for them to understand the steps required to recognise and respond to symptoms (Anagnostou and Turner, 2019).
Children and young people prescribed an adrenaline autoinjector will need to have this with them at all times, including in school. This will require school staff being trained to use the devices (RCPCH, 2011). In 2017, the Department of Health released guidance for schools in England regarding purchasing adrenaline autoinjector (AAI) devices without a prescription. These auto-injectors are for emergency use on children who are at risk of anaphylaxis but whose own device is not available or not working (Department of Health, 2017). This is supported by a national campaign called ‘Spare Pens in Schools’, including a website (https://www.sparepensinschools.uk) to offer guidance for school staff and families.
Emotional support
For children, young people and their families the experience of anaphylaxis can be frightening. The journey to identifying a cause and then managing care in order to prevent further episodes can also be difficult (RCPCH, 2011). Family-centred care is a core concept in nursing children and young people, and remains essential when considering anaphylaxis (Shields et al, 2012).
Nurses need to plan, implement and evaluate the care in partnership with the whole family (Institute for Patient and Family Centred Care, 2010). This means providing psychological support; exploring the anaphylaxis event, ensuring understanding and providing high-quality education to maximise safety. Some specialist teams may have psychology provision to ensure the wellbeing of the client and family. Families should be signposted to local or online support groups to access additional information and input from peers (NICE, 2011b), such as the Anaphylaxis Campaign and Allergy UK.
It should be acknowledged that young people may find managing their condition particularly challenging. This is multifactorial and unique to each individual. However, factors include the impact on engagement of physical, social and emotional changes (Worth et al, 2013). Challenges may arise such as concordance with management plans and ensuring safe transition to adult services (Worth et al, 2013). It is vital to include the young person in all decisions, ensure they are given space to be listened to and identify any increasing risks.
Summary
It is likely that all nurses will be exposed to anaphylaxis at some point in their careers. Anaphylaxis is a severe, life-threatening and generalised reaction (Resuscitation Council UK, 2012). It is a condition on the rise, particularly in children and young people (Grabenhenrich et al, 2016).
There are key features that should raise a strong suspicion of anaphylaxis, as highlighted in Box 3. As well as prompt management, children and their families will require emotional support.