Understanding Allergies and Anaphylaxis

As a paramedic and first aid trainer, I’m often asked about allergies - what they are, how serious they can be, and what to do in an emergency. Here’s a straightforward guide to help you feel more confident.

What is an allergy?

An allergy happens when the body’s immune system overreacts to something that is usually harmless.

Instead of ignoring the substance (called an allergen), the body treats it like a threat - similar to a virus or bacteria. It produces antibodies and “remembers” the allergen, so the next time the body is exposed, it reacts more quickly.

This reaction involves the release of chemicals such as histamine, which causes many of the symptoms we associate with allergies.

In mild reactions, the response tends to stay localised (for example, just affecting the skin or nose). In severe reactions, the response becomes widespread and can affect airway, breathing and circulation - this is called Anaphylaxis.

Most allergic reactions happen within minutes, but some can be delayed by several hours (or occasionally longer)

Unfortunately, the number of people affected by allergies is rising. Although anaphylaxis is less common, it is a serious, life-threatening condition that requires immediate treatment.

Common allergy triggers

Food triggers include:

• Cow’s milk

• Eggs

• Peanuts and tree nuts

• Wheat (gluten), barley and rye

• Fish and shellfish

• Soya

• Sesame seeds

• Lentils, beans and peas

• Celery

Non-food triggers include:

• Pollen (hay fever)

• Dust mites

• Animal hair

• Insect stings

• Latex

• Some medications

Introducing food allergens to babies

Current guidance encourages introducing common food allergens from around 6 months of age.

Here are some helpful tips:

• Introduce one new food at a time

• Start with very small amounts

• Watch for any signs of a reaction (If a reaction occurs, stop the food and seek medical advice)

If your baby has eczema , an existing allergy, or a strong family history of allergies it’s best to speak to your GP or health visitor before introducing certain foods.

Once a food is introduced and tolerated, it’s important to keep it in the diet regularly, as this may help reduce the risk of developing an allergy.

Thankfully, many children outgrow their allergies. However, some can be lifelong and may require treatment, such as antihistamines. In more serious cases, children may be prescribed an adrenaline auto-injector (often known as an EpiPen) to use in an emergency.

Signs and symptoms (mild to moderate allergy)

These can include:

• Sneezing

• Runny or blocked nose

• Red, itchy or watery eyes

• Skin rash or hives

• Mild swelling (e.g. lips or eyes)

• Coughing or mild wheeze

• Nausea, tummy pain, vomiting or diarrhoea

• Worsening of asthma or eczema

Signs and symptoms (severe allergic reaction - anaphylaxis)

Anaphylaxis is a life-threatening emergency.

It typically involves problems with:

• Airway (swelling of tongue or throat, difficulty swallowing)

• Breathing (wheezing, struggling to breathe)

• Circulation (dizziness, pale or clammy skin, collapse)

Other signs may include:

• Swelling of the lips, face or tongue

• A widespread rash or hives

• Vomiting or diarrhoea

• Sudden anxiety

What to do if you suspect anaphylaxis

1. Call 999 immediately

2. Remove the trigger

3. Assist with EpiPen (if one available)

4. Position the person correctly by lying them flat with legs raised . However, If breathing is difficult, they may prefer to sit up with you supporting them.

5. Stay with them until help arrives

Final thoughts

If your child is diagnosed with an allergy, you’re not alone - there’s lots of support out there. What feels overwhelming at first quickly becomes routine, and you’ll soon be confidently reading labels and avoiding triggers.

For those starting the weaning journey, it’s completely normal to feel a little nervous about introducing new foods. Take it one step at a time, and remember that most children tolerate foods without any issues.

Luckily, most allergic reactions are mild, but knowing when something is more serious is key. Recognising the signs of anaphylaxis and acting quickly can save a life.