Understanding Allergies, Intolerances and Anaphylaxis

An allergy is the body’s adverse reaction to a specific food, substance or environmental trigger. While many substances are harmless to most people, they can cause significant reactions in individuals who are allergic.

What is an Allergen?

A substance that causes an allergic reaction is known as an allergen. Common allergens include:

• Pollen
• Latex
• Nuts
• Eggs
• Shellfish

These substances may have no impact on most people but can trigger reactions ranging from mild irritation to severe medical emergencies in others.

How Allergies Affect the Body

Allergic reactions occur when the immune system mistakenly identifies an otherwise harmless substance as dangerous.

When this happens, the body creates antibodies to fight the perceived threat. Upon future contact with the allergen, the immune system responds quickly by releasing chemicals such as histamine, which causes allergy symptoms.

Symptoms can vary depending on how the allergen enters the body.

Common symptoms include:

• Sneezing
• Wheezing
• Coughing
• Skin irritation or rashes
• Itching or swelling

For example, inhaled allergens such as pollen often affect breathing, while skin contact with certain substances may result in irritation or rashes.

Common Allergy-Related Conditions

Some well-known allergic conditions include:

• Asthma
• Eczema
• Hay fever

Although many allergic reactions are mild, some can rapidly become severe and develop into anaphylaxis.

What is Anaphylaxis?

Anaphylaxis is a severe and life-threatening allergic reaction that affects the whole body, particularly the respiratory and circulatory systems.

Allergens can enter the body in several ways, including:

• Ingestion – eating or drinking something
• Inhalation – breathing substances into the lungs
• Skin contact – touching an allergen
• Injection – such as an insect sting or medication

Signs and Symptoms of Anaphylaxis

Recognising the signs of anaphylaxis quickly can help save a life.

Symptoms may include:

• Itchy skin or a raised red rash
• Swelling of the lips, eyes, hands or feet
• Feeling dizzy, faint or light-headed
• Breathing difficulties or wheezing
• Narrowing of the airways
• Abdominal pain, sickness or vomiting
• Collapse or loss of consciousness

Anaphylaxis must always be treated as a medical emergency.

Allergy, Sensitivity or Intolerance?

Not all reactions to foods or substances are true allergies.

What is a Sensitivity?

A sensitivity is an exaggerated reaction to a substance that would not normally cause symptoms.

For example, some people are highly sensitive to caffeine and may experience shaking, palpitations or discomfort even after small amounts.

What is an Intolerance?

An intolerance does not involve the immune system.

Instead, it occurs when the body struggles to process certain foods or ingredients, such as lactose or gluten.

Symptoms may include:

• Bloating
• Diarrhoea
• Stomach pain
• Digestive discomfort

Some individuals may tolerate small amounts, while others experience symptoms lasting several days.

Unlike intolerances, even tiny amounts of an allergen can trigger a serious allergic reaction.

Treatment for Severe Allergic Reactions

Severe allergic reactions require immediate treatment.

Adrenaline auto-injectors, sometimes called emergency allergy pens, are used to provide a measured dose of adrenaline into the muscle.

This medication helps reduce the severity of the reaction and may be life-saving while waiting for emergency medical help.

If you suspect someone is experiencing anaphylaxis:

• Dial 999 immediately and request an ambulance
• Help the person use their prescribed adrenaline auto-injector
• Keep them resting and do not allow them to stand or walk
• Monitor their condition until help arrives

Using Adrenaline Auto-Injectors

Adrenaline auto-injectors are prescribed by a doctor and are not available over the counter.

Many people are advised to carry two devices, as a second dose may be required if symptoms do not improve after 5 to 15 minutes.

Auto-injectors are designed for single use only.

Common brands include EpiPen and Jext. While designs vary, both are intended to deliver adrenaline quickly into the outer thigh.

Instructions are printed directly on the devices and users should familiarise themselves with their prescribed injector.

After Giving Adrenaline

Once adrenaline has been administered:

• Do not allow the person to stand or walk
• Keep them comfortable and under observation
• Always wait for emergency services, even if symptoms improve
• Provide any used auto-injectors to paramedics

This helps emergency responders understand what treatment has already been given and ensures safe disposal of the device.