allergies

Allergies

Allergies happen when your immune system reacts to something harmless - like pollen, pet dander, or certain foods - as if it were a threat.
This reaction can cause symptoms like sneezing, itchy eyes, skin rashes, or more serious effects such as breathing problems or anaphylaxis.
Allergies are very common and can affect people of all ages. While most allergic reactions are mild, some can interfere with daily life or be life-threatening.

What causes allergies?

Allergies are caused by the immune system overreacting to a normally harmless substance known as an allergen. When exposed, your body produces antibodies and releases chemicals like histamine, which cause the symptoms of an allergic reaction.
Common allergens include:

Airborne allergens:

• Pollen: From trees, grasses, and weeds - known as hay fever or allergic rhinitis
• Dust mites: Tiny bugs that live in house dust
• Animal dander: Skin flakes and saliva from cats, dogs, and other animals
• Mould spores: Fungi found in damp or humid environments

Food allergens:

• Milk
• Eggs
• Peanuts
• Tree nuts (e.g. almonds, walnuts)
• Shellfish and fish
• Wheat and soy

Other allergens:

• Insect stings: Such as bee or wasp stings
• Latex: Found in gloves, balloons, and some medical products
• Medications: Such as penicillin or aspirin
• Chemicals: Found in cleaning products, perfumes, or cosmetics

What are the symptoms of allergies?

Allergy symptoms can vary depending on the allergen and how your body reacts. Common symptoms include:

• Sneezing
• Runny or blocked nose
• Itchy or watery eyes
• Skin rashes or hives (urticaria)
• Swelling of the lips, face, or eyes (angioedema)
• Coughing or wheezing
• Shortness of breath
• Nausea or vomiting (more common with food allergies)

In severe cases, allergies can cause anaphylaxis, a life-threatening reaction that needs emergency treatment. Signs include difficulty breathing, a fast heartbeat, severe swelling, dizziness, or collapse. Call 999 immediately if this happens.

How are allergies diagnosed?

If you think you have an allergy, your GP or pharmacist can help guide you. You may be referred for testing, which could include:

• Medical history and symptom tracking
• Skin prick test: A small amount of allergen is placed on the skin to see if a reaction occurs
• Blood tests: Such as specific IgE tests to detect allergic antibodies
• Elimination diet: For suspected food allergies, certain foods may be removed and reintroduced to monitor symptoms

These tests help identify the trigger and guide treatment options.

Allergy treatments

There is no cure for allergies, but symptoms can usually be managed with medication and avoidance of triggers.

Self-care and avoidance

• Avoid known allergens: Stay indoors on high pollen days, use dust mite covers, avoid specific foods
• Keep windows closed: During pollen season
• Shower after being outdoors: To remove pollen from your skin and hair
• Use air filters or dehumidifiers: To reduce indoor allergens like mould and dust

Medications

1. Antihistamines: Help relieve sneezing, itching, and runny nose (e.g. cetirizine, loratadine, chlorphenamine)
2. Nasal sprays: Such as steroid sprays (e.g. beclometasone, fluticasone) to reduce nasal inflammation
3. Eye drops: For itchy or watery eyes (e.g. sodium cromoglicate)
4. Adrenaline auto-injectors (e.g. EpiPen): For people at risk of severe allergic reactions

Immunotherapy

• For certain allergies like pollen, dust mites, or bee venom, immunotherapy may be recommended
• Involves regular small doses of allergen to build tolerance over time
• Can be given as injections or under-the-tongue tablets

Will treatment help?

Most people with mild to moderate allergies find their symptoms improve significantly with the right treatment and avoidance strategies.
For seasonal allergies like hay fever, antihistamines and nasal sprays are often very effective when taken regularly during high-pollen months.
Those with severe or complex allergies may benefit from specialist care or long-term immunotherapy.

Allergy treatment side effects

Most allergy medicines are safe and well tolerated, but possible side effects include:

• Antihistamines: Drowsiness (more common with older types like chlorphenamine), dry mouth, or dizziness
• Nasal sprays: Nosebleeds or irritation if used long-term or incorrectly
• Eye drops: Mild stinging or temporary blurred vision
• Adrenaline injectors: Fast heart rate, shakiness - only used in emergencies

Speak to your doctor or pharmacist if you are unsure which treatment is right for you, or if side effects become bothersome.