An allergic reaction happens when your immune system overreacts to a substance that is normally harmless to most people. These substances are known as allergens, and they can include foods, insect stings, medicines, pollen, and dust mites. Allergic reactions can range from mild to severe, and severe allergic reactions can be life-threatening.
Types of Allergy: Allergens and Triggers
Many different types of allergic reactions exist, and each type of allergy involves a specific trigger that causes your immune system to react.
The most common food allergies involve cow’s milk allergy, egg, peanut, tree nuts, sesame, soy, fish, shellfish, and wheat.
Allergies to insect venom from bees, wasps, and ants are one of the most common causes of severe allergic reactions in Australia.
Drug allergies occur when your immune system reacts to a medicine, particularly penicillin, and non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen.
Environmental triggers include pollen from grasses, weeds, trees, house dust mites, mould spores, and animal dander (skin flakes from pets).
Latex allergies are caused by exposure to the substance, such as when wearing disposable gloves. Some people with latex allergy also react to certain foods like banana, avocado, and kiwifruit because they contain similar proteins.
Signs and Symptoms of an Allergic Reaction
Allergy symptoms can range from mild to severe, depending on the person and the allergen involved. Signs and symptoms of a mild to moderate allergic reaction can include swelling of the lips, face, or eyes, hives or welts appearing on the skin, tingling or itching in the mouth, abdominal pain, and vomiting. A runny nose, sneezing, and watery or itchy eyes are also common, particularly with hay fever and asthma symptoms related to environmental allergens.
Anaphylaxis Symptoms and Causes
Anaphylaxis is a severe type of allergic reaction that should always be treated as a medical emergency. Warning signs of anaphylaxis include any one of the following:
-
difficult or noisy breathing
-
swelling of the tongue
-
swelling or tightness in the throat,
-
a wheeze or persistent cough
-
difficulty talking or a hoarse voice
-
persistent dizziness
-
collapse
-
pale skin
-
limp posture
-
abdominal pain
-
vomiting
Most cases of anaphylaxis occur after a person is exposed to an allergen they are allergic to, usually food, an insect sting, or a medicine. People with asthma are at higher risk of severe allergic reactions, and asthma, food allergy, and high risk of anaphylaxis frequently occur together.
Anaphylaxis Treatment Options
The Australasian Society of Clinical Immunology and Allergy (ASCIA) provides clear guidelines for responding to anaphylaxis.
Call Triple Zero (000) for an ambulance immediately. Tell the operator that someone is having a severe allergic reaction (anaphylaxis).
Adrenaline autoinjectors contain a single dose of adrenaline designed to be used by anyone, even without medical training. When injected into the outer mid-thigh during anaphylaxis, adrenaline helps maintain blood flow to the heart and reduces swelling in the airways. If the person’s symptoms persist or return five minutes after the first injection, give another dose using a second adrenaline device if available.
Lay the person flat and do not allow them to stand or walk. If the person is unconscious, place them in the recovery position on their side. If they are pregnant, place them on their left side. If they struggle to breathe lying down, allow them to sit upright with their legs outstretched.
Monitor until help arrives. Stay with the person at all times and watch for any changes in their condition. Be prepared to start CPR if the person becomes unresponsive and stops breathing normally.
Living With Allergies?
Living with allergies requires ongoing management and preparation. First aid training provides essential skills that could help you save a life. Enrol in an accredited first aid training course today and gain the confidence to respond effectively to allergic emergencies. Your knowledge could make the difference between life and death for someone experiencing anaphylaxis.
FAQs
Is Asthma Different From an Allergic Reaction?
Asthma is a chronic condition affecting the airways. However, allergy is one of the major factors associated with asthma development, and around 80% of people with asthma have allergies.
Why Does the Immune System Overreact to Harmless Substances?
Researchers do not fully understand why some people develop allergies while others do not. Theories suggest that reduced exposure to infections in early life, vitamin D deficiency, and delayed introduction of common allergens may contribute to developing allergic responses. Genetics also play a role, as people with a family history of allergies have a higher tendency to develop allergic conditions themselves.
What Is the Difference Between a Food Allergy and a Food Intolerance?
A food intolerance does not involve the immune system and typically causes digestive symptoms like bloating, gas, or diarrhoea. Food intolerances are uncomfortable but not dangerous, whereas food allergies require strict avoidance of the trigger food and may require carrying an adrenaline autoinjector.
