Allergies can be triggered by hundreds of different causes and present themselves in many ways: some symptoms barely noticeable or mildly annoying and some that are severe and potentially life-threatening.

In this blog, we look at anaphylaxis, a frightening and sometimes fatal allergic reaction.

What is Anaphylaxis?

An allergic reaction occurs when the immune system reacts inappropriately in response to the presence of a food or substance that it wrongly perceives to be a threat. 

Chemicals, such as histamine, are released from cells in the blood and tissues and can cause swelling in the skin, lips, mouth, throat or lower airway causing difficulty in swallowing and/or breathing.

Anaphylaxis (pronounced ana-fil-ax-is) is a severe and often sudden allergic reaction. 

Symptoms usually start within minutes and rapidly progress but can occur up to 2-3 hours later.  Potentially life-threatening, anaphylaxis always requires an immediate emergency response.

If death occurs as a result of anaphylaxis, the cause is usually either respiratory or cardiovascular.

What are the symptoms of anaphylaxis?

UK charity, The Anaphylaxis Campaign highlights the ABC Symptoms – Airway, Breathing, Consciousness/Circulation:

• persistent cough 

• vocal changes (hoarse voice) 

• difficulty in swallowing 

• swollen tongue 

• difficult or noisy breathing 

• wheezing (like an asthma attack) 

• feeling lightheaded or faint. 

• clammy skin 

• confusion 

• unresponsive/unconscious (owing to a drop in blood pressure)

The NHS mentions that there may also be other allergy symptoms, including an itchy, raised rash (hives); feeling or being sick; swelling (angioedema) or stomach pain.

What allergens can trigger anaphylaxis?

Common non-food allergen triggers are natural rubber/latex, insect stings and penicillin.  Food allergies are a common cause of anaphylaxis, including:

• peanuts

• tree nuts

• milk

• eggs

• shellfish

• fish 

• sesame seeds

• kiwi fruit

However many other foods have been known to cause the reaction and some people can react to tiny amounts of the food they’re allergic to.

Anaphylaxis and food allergies

In July 2016, 15-year-old Natasha Ednan-Laperouse died following an anaphylactic reaction to a shop-bought baguette.

Natasha had suffered from allergies since she was a baby, and she and her parents were super vigilant, always scrutinising the labelling of any unfamiliar food.  She had looked at the label on the baguette and believed it to be safe.  

What the label didn’t tell her was that the bread contained sesame seeds, an ingredient she knew she was allergic to.  Food labelling law at the time didn’t require food freshly made on the premises to itemise individual ingredients.

Since her tragic death, Natasha’s parents have received MBEs for their tireless work to raise awareness of food allergies and better food labelling.  

Natasha’s Law comes into force in October 2021, and will mean more thorough labelling for food made on the premises of takeaways, cafes etc.  You can find out more about Natasha’s Law here.

Are severe food allergies becoming more common?

The general consensus among experts from around the world is, yes, they are becoming more common.  

In her book The End of Food Allergy, Stanford University allergy specialist, Kari Nadeau, says that the rate of food allergies worldwide has increased from around 3% of the population in 1960 to around 7% in 2018.

In England, for example, there was a 72% rise in the number of children being admitted to hospital with anaphylaxis between 2013 and 2019. 

However, theories as to why, and what we can do about it, vary.

Some believe it’s because we’re more aware of allergies and allergic reactions; some have identified a link between higher instances of allergies in the more economically “developed” a country becomes.  

Others think that in Western modern life, we’re not always exposed to the good bacteria and microorganisms that can “educate” our gut and immune systems; and/or that the more antibiotics we’re given as babies and children, the more likely we are to have allergies.

Advice has changed over the years too.  For example, 20+ years ago, pregnant women were encouraged to avoid peanuts and parents were advised not to give them to children under 3.  This is no longer the case, as further research discovered that the early introduction of peanuts can reduce peanut allergies by as much as 80%.

What to do if someone has anaphylaxis

Many people who know that they have a severe allergy will carry an EpiPen®.  This is an auto-injector that administers a shot of adrenaline to combat the effects of the allergic reaction.

The NHS gives the following advice on what to do if someone has anaphylaxis:

1. Use an adrenaline auto-injector if the person has one – but make sure you know how to use it correctly first.

2. Call 999 for an ambulance immediately (even if they start to feel better) – mention that you think the person has anaphylaxis.

3. Remove any trigger if possible – eg food nearby or in their mouth.

4. Lie the person down flat – unless they're unconscious, pregnant or having breathing difficulties.

5. Give another injection after 5 to 15 minutes if the symptoms do not improve and a second auto-injector is available.

The future of anaphylaxis and food allergies

The future is hopeful.  Lots of research into the causes and treatment of food allergies is ongoing around the world, and awareness of food allergies and their dangers is increasing, with initiatives like Food Allergy Awareness Week. 

Improvements in food labelling – such as Natasha’s Law – will be invaluable in preventing fatalities, making food manufacturers and retailers more aware of the issues and helping allergy sufferers make safe choices.

If you have experienced a sudden allergic reaction in the past, then you may be at risk of anaphylaxis even if you have not had it before.  It’s always best to get checked out and you can ask your GP for a referral to an allergy clinic.