---
title: "Allergic Reactions | First Aid Glossary"
description: "Immune system's response to allergens, can range from mild to severe symptoms. Learn warning signs and first aid steps to help you respond safely."
canonical: "https://www.australiawidefirstaid.com/resources/glossary/allergic-reactions"
---

# Allergic Reactions

[Resources](https://www.australiawidefirstaid.com/resources) › [Glossary](https://www.australiawidefirstaid.com/resources/glossary)

## What are Allergic Reactions?

Allergic reactions occur when the immune system overreacts to a substance (allergen) that is normally harmless. Symptoms can range from mild (rashes, itching, and swelling) to severe (difficulty breathing, anaphylaxis). Common allergens include certain foods, insect stings, medications, pollen, pet dander, dust and latex.

Allergic reactions occur when the immune system responds to foreign substances, such as pollen, food, insect stings, or medications, that are generally harmless to most people. These reactions can vary in severity from mild symptoms like itching, hives, and nasal congestion to severe, potentially life-threatening conditions known as anaphylaxis. Anaphylaxis can cause symptoms such as difficulty breathing, swelling of the throat and tongue, rapid pulse, and a drop in blood pressure.

Immediate treatment is crucial for anaphylactic reactions, typically involving the administration of adrenaline (epinephrine) via an auto-injector. Antihistamines may be used for milder reactions to alleviate symptoms. Following the initial management, it is essential to seek emergency medical assistance to ensure the reaction is fully treated and monitored.

## Symptoms

- Rashes
- Itching
- Swelling
- Difficulty breathing, sneezing
- Anaphylaxis

## First Aid Steps

1. Remove the allergen if possible
2. Apply a cold compress to reduce swelling
3. Use over-the-counter antihistamines for mild reactions
4. Seek medical help if symptoms worsen or do not improve

> Immune responses to allergens causing various symptoms, mild to severe.

## Related video: How Well Do You Understand Allergic Reactions? Take the Ultimate Quiz!

[Watch on YouTube](https://www.youtube.com/watch?v=vE7gVVgk6QE)

## Learn this hands-on

A nationally accredited first aid course covers this and much more. [Find a course and check live session availability](https://www.australiawidefirstaid.com/#find-course).

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