Allergic Reactions Emergency First Aid

Overview

An allergic reaction happens when your body's immune system overreacts to a substance that is usually harmless, like certain foods, insect stings, or medicines. This can cause symptoms that range from mild to life-threatening.

Allergies are very common. Up to 1 in 3 people have some form of allergy, but severe reactions are much rarer.

Anyone can have an allergic reaction, at any age. People with a history of allergies, asthma, or a previous severe reaction are at higher risk.

Symptoms

Common symptoms

• Itchy skin, hives (raised, red bumps)
• Sneezing, runny or blocked nose
• Itchy, watery eyes
• Mild swelling of the lips, face, or tongue
• Upset stomach, nausea, or vomiting

Symptoms in children

• Hives or a rash
• Tummy pain, vomiting, or diarrhea
• Sudden sneezing or coughing
• Flushed skin
• Fussiness, clinginess, or tiredness

Symptoms in older adults

• Shortness of breath or wheezing
• Dizziness or feeling faint
• Rapid heart rate
• Low blood pressure
• Confusion or anxiety

Causes

Main causes

• Foods such as peanuts, tree nuts, eggs, milk, shellfish, and wheat
• Insect stings from bees, wasps, or ants
• Medications like antibiotics, pain relievers, and contrast dyes
• Latex (rubber) gloves or condoms
• Less commonly, exercise or temperature changes

Risk factors

• A previous allergic reaction
• Asthma, eczema, or hay fever
• A family history of allergies or anaphylaxis
• Being young or having a weakened immune system

When to see a doctor

See a doctor urgently if:

• If you have hives, swelling, or vomiting that does not improve quickly
• If you have any breathing difficulty, even if it seems mild
• If you have had a severe reaction before and are exposed to a known trigger

Book a routine appointment if:

• To identify what you are allergic to through testing
• To get a written action plan for managing reactions
• To review your emergency medicines with a pharmacist or doctor

Diagnosis

A doctor will ask about your symptoms and what you were exposed to before the reaction started. They may also examine your skin, breathing, and heart rate.

Tests that may be done

• Skin prick testing
• Blood tests for allergy antibodies
• A controlled food challenge (in a medical setting)

What to expect at your appointment

You may be referred to an allergy specialist. The specialist can help confirm the cause and create a personal emergency plan.

Treatment

Treatment depends on how severe the reaction is. For mild reactions, avoiding the trigger and taking medicines to control symptoms may be enough. For severe reactions, emergency medical care is essential.

Self-care at home

• Remove or avoid the trigger if possible
• Rinse your skin with water if the trigger was on your skin
• Apply a cool, damp cloth to itchy areas
• Take an over-the-counter antihistamine as recommended by your pharmacist or doctor
• Sit or lie down calmly until symptoms improve

Medical treatments

For severe reactions, doctors and emergency teams may give you adrenaline (epinephrine) through an auto-injector, oxygen to help with breathing, and fluids through an IV line. If you have been prescribed an auto-injector, always carry it and know how to use it. Your doctor will show you what to do.

Living with this condition

Learn to recognize early symptoms and have an action plan. Wear a medical alert bracelet if you have had a severe reaction. Carry your emergency medicines at all times. Make sure close friends, family, and co-workers know what to do.

Lifestyle tips

• Avoid your known triggers
• Always ask about ingredients in foods when eating out
• Read food and medicine labels carefully
• Tell doctors, dentists, and pharmacists about all your allergies

Diet and exercise

If food allergies are a problem, working with a dietitian can help you eat safely. For exercise-induced reactions, avoid exercising alone and carry your emergency kit with you.

Mental health and emotional wellbeing

Living with allergies can cause anxiety about the next reaction. It is normal to feel worried. Talk to your doctor or a mental health professional if these feelings are affecting your daily life.

Prevention

The best way to prevent an allergic reaction is to avoid your known triggers. Allergen immunotherapy (sometimes called allergy shots or drops) can help reduce sensitivity over time.

Vaccines

There is no vaccine that prevents allergic reactions. However, certain lifestyle steps and, in some cases, immunotherapy can lower your risk.

Screening programmes

If you have severe reactions, allergy testing can help identify triggers. Talk to your doctor about whether this is right for you.

Complications

If left untreated

• Severe anaphylaxis can block your airways and make it hard to breathe
• Blood pressure may drop dangerously low (anaphylactic shock)
• Delayed reactions can occur hours after the first symptoms
• Repeated severe reactions without monitoring can be life-threatening

Long-term outlook

With the right care and planning, most people with allergies live full and active lives. The key is to know your triggers, carry your emergency medicine, and get help immediately when symptoms are severe.

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