Anaphylaxis, also referred to as anaphylactic shock, is the most severe form of allergic reaction. It happens a when person comes into contact with a trigger that they are allergic to such as nuts, eggs or dairy for example. Their body forms a massive response to the trigger and this can be fatal in some circumstances.
The commonest triggers for anaphylaxis include nuts, eggs, dairy, shellfish, bee/wasp stings, latex, medicines such as antibiotics (especially penicillin), or painkillers such as ibuprofen. There are many more potential triggers for anaphylaxis. Individual triggers are unique to the person and so someone may have anaphylaxis on exposure to nuts, but not react to dairy; another person may react to both. Some people suffer with anaphylaxis in response to an unknown trigger. What people with anaphylaxis share is that whatever their unique trigger may be, their bodies mount a massive immune response affective multiple body systems on exposure to the trigger. This results in the common occurrence of symptoms identifying anaphylaxis.
Symptoms of Anaphylaxis
The commonest symptoms of anaphylaxis are skin changes and airway swelling as mentioned in the table below. It is important to be aware that severe case of anaphylaxis can occur without the typical skin changes. Children may sometimes get the breathing symptoms before the appearance of skin changes. Symptoms develop rapidly and often peak from 5 to 30 minutes after exposure to a trigger and may last for days. The most severe reactions can take just seconds to develop and become life-threatening.
|Airway||Hoarseness, cough, tightness, swelling ( of the tongue and/or lips), difficulty breathing, noisy breathy (stridor).|
|Breathing||Runny nose, nasal congestion, chest tightness, wheeze.|
|Circulatory||Lightheadedness, fainting, chest pain, palpitations.|
|Gut||Nausea, vomiting, abdominal cramping, diarrhoea.|
|Skin||Rash, itching, flushing, puffy skin, cold, clammy skin, swelling.|
|Sensory||Headache, dizziness, blurred vision, seizures, metallic taste, feeling of impending doom.|
What is anaphylactic shock?
Anaphylactic shock refers to an anaphylactic reaction severe enough to cause reduced oxygen delivery to the body due to inadequate circulation of blood (circulatory failure). The term is often used interchangeably with anaphylaxis.
Anaphylaxis First Aid
Anaphylaxis is an emergency that requires immediate medical treatment. Early recognition and alert of emergency services by calling 999 is the most important step an untrained member of the public can take to help. When speaking to the emergency operator, inform them that you think the person is having an allergic reaction.
If the person knows what their trigger is and if it is possible, then this could be removed. For example, a bee or wasp stuck in the skin, or latex items could potentially be removed. However, we recognise that in typical scenarios of food ingestion or trigger inhalation, this is not possible and it is not advisable to even try.
If the person already has a diagnosis of anaphylaxis, they should have an adrenaline (epinephrine) auto-injector with them. An auto-injector is a medical injector device that is pre-loaded with the correct dose of adrenaline/epinephrine for the person that needs it. Once you have recognised the symptoms of anaphylaxis, check if the person has their auto-injector and help them to use it if they are able. If the person is unable to use it and you have been trained, then you can use it for them to give them their dose of adrenaline/epinephrine.
The most used auto-injectors are the EpiPen©, Emerade© and JEXT© auto-injectors.
If the person is responsive and breathing, help them sit up. If they are showing signs of low blood pressure without breathing difficulty, lie them down and elevate their legs.
Do not lie allow a pregnant woman to lie flat on her back. Pregnant women should lie on their left side.
If the person becomes unresponsive but continues to breath, place them in the recovery position. This will help keep their airway clear and reduce the risk of their stomach contents rising up and entering their lungs.
If the person becomes unresponsive and stops breathing, they require immediate CPR (cardiopulmonary resuscitation).
Adrenaline (epinephrine) is the main survival-altering treatment for anaphylaxis. Health professions may administer additional adrenaline if the person’s response to their initial dose of adrenaline was insufficient. Other drugs such as antihistamines, steroids, and fluids may also be required. Oxygen and nebuliser medications may be given to support breathing. Very severe cases of anaphylaxis require intensive care. Less severe cases will commonly require up to 12 hours of observation in hospital before a person can be safely discharged.
During this time blood tests may be requested to confirm anaphylaxis biochemically. These will help inform future management.
If you or someone you care for has been treated for anaphylaxis, then they will require follow up with an Allergy specialist with a view to optimising future prevention and treatment.
For more information on Anaphylaxis, see the some of the useful links below: