Anaphylaxis can be deadly
Some allergic reactions are mild and harmless, but others can be very severe and potentially lifethreatening – the ones at this end of the spectrum are known as "anaphylaxis".
Ioften get asked whether there are more ‘‘allergies’’ around than there used to be. The answer would have to be yes – but it is important to understand the difference between an allergy to something and an intolerance.
Yes, they can both make you feel awful, and they can both require treatment and avoidance of whatever the trigger is, but a true allergy involves the body’s immune system, whereas an intolerance doesn’t.
An allergic reaction happens when a person is exposed to something their body is hypersensitive to. In another individual this exposure would do nothing, but in a hypersensitive person it starts a cascade of immune responses, resulting in symptoms known as an allergic reaction.
Some allergic reactions are mild and harmless, but others can be very severe and potentially lifethreatening – the ones at this end of the spectrum are known as ‘‘anaphylaxis’’.
To be classified as true anaphylaxis, a reaction needs to meet the following criteria:
❚ Sudden onset.
❚ Rapid progression of symptoms and severity.
❚ Life-threatening airway, breathing or circulation problems if left untreated.
Current rates show that around three people for every 10,000 in the population will have an anaphylactic reaction every year.
So although it is still relatively unusual, it is not rare, and knowing what to do if you or someone you are with experiences this can truly be the difference between life and death.
Typically, the most common triggers for anaphylaxis are:
❚ Foods – such as peanuts, pulses, tree nuts (like, hazelnuts, almonds, brazil nuts), fish and shellfish, eggs, milk, sesame.
❚ Venom – particularly bees and wasps.
❚ Medication – antibiotics, morphine or codeine-based drugs, certain types of anaesthetics, antiinflammatories, and muscle relaxants.
Anaphylactic reactions to certain vaccinations can occur too but are rare.
Anaphylaxis can be very obvious (for example, if you get stung by something, then rapidly become unwell), but it can be more subtle, so be aware of the following signs and symptoms, and act quickly if you are concerned:
❚ Skin changes – this can (but doesn’t necessarily) include generalised itching, raised red hives or bumps on the skin, runny nose, itchy eyes, swelling or puffiness of the face.
❚ Early airway involvement – itching of the palate or ear canals, shortness of breath, wheezing or stridor (a noisy type of breathing).
❚ Heart racing and palpitations.
❚ Nausea, vomiting and abdominal pain.
❚ Feeling faint, collapsing or loss of consciousness.
❚ The hands, feet and area around the mouth may look blueish, or you may notice pallor and sweating.
❚ Interestingly, people who have had anaphylaxis often describe a feeling of impending ‘‘doom’’, or extreme fear that they are going to die – if someone has seemingly mild allergic symptoms, but is expressing this, it is worth taking it seriously.
The key to looking after someone who has had an anaphylactic reaction is to get them help immediately. Call 111 and explain the situation – they will talk you through what you can do until the paramedics arrive. Follow emergency procedure as you would for anyone who had collapsed – assess their airways, breathing and circulation, then provide resuscitation with chest compressions and mouth-to-mouth breathing if required.
If the person has had this kind of reaction before, they may have an ‘‘epipen’’ with them – administering this immediately will save their life. They are designed to be given by anyone, and are simple to use. The active ingredient in an epipen is adrenaline, and it will halt the anaphylaxis, enabling them to breathe again.
Antihistamines can be given if available, but are absolutely not a substitute for adrenaline, so even if someone starts to look a bit better, they could deteriorate later, so proper medical assessment is still required.
❚ Dr Cathy Stephenson is a GP and forensic medical examiner.