Home · Glossary · Allergic Reactions

Allergic Reactions

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

All glossary terms

What are Allergic Reactions?

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.

Allergic Reactions

Symptoms

  • Rashes

  • Itching

  • Swelling

  • Difficulty breathing, sneezing

  • Anaphylaxis

First Aid Steps

  • Remove the allergen if possible

  • Apply a cold compress to reduce swelling

  • Use over-the-counter antihistamines for mild reactions

  • Seek medical help if symptoms worsen or do not improve

Takeaway to Remember

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.

Reference

First aid e-manual — ALLERGIC REACTIONS AND ANAPHYLAXIS

LEARN IT PROPERLY

Our nationally recognised first aid courses cover this and more, hands-on.

See courses

BOOK IN Casuarina

See upcoming Casuarina dates and book online in minutes.

See dates

MORE TERMS

Browse the full first aid glossary — search or filter A–Z.

Open glossary