All About Allergies

About Allergies

An Allergy occurs when the body's immune system reacts to a foreign substance it identifies as a harmful allergen. This may include substances consumed, inhaled, injected or made contact with from certain foods, pollen, insects, metals, moulds, etc.

These substances (also referred to as allergic triggers) are harmless to most people; however, for an allergic person, it affects their immune system and reacts by producing antibodies (immunoglobulins) to fight the foreign substances. This leads to symptoms that can be mild to severe and life-threatening.

These symptoms can have different reaction times; some happen within minutes, while others can take days. Reactions can also affect a specific part of the body or can affect the body as a whole.

The time it takes the body to react and the way by it reacts is classified into four types of hypersensitivity reactions:

• Type I- Immediate reactions
• Type II- Cytotoxic antibody mediated reactions
• Type III- Immune complex reactions
• Type IV- Cells-mediated reactions

Type I, II and III reactions are classified as immediate reactions as they occur within 24 hours of allergen exposure. Type IV reactions are classified as delayed reactions as they after over 24 hours of allergen exposure.

The table below breaks down the different hypersensitivity reactions.

4 Types of hypersensitivity reactions

A general course of treatment for allergic reactions varies by type of reaction. For Minor reactions, prescribed and over-the-counter medications may be used, such as but not limited to antihistamines. For severe reactions, and in the case of an emergency, Epinephrine may be used, followed by seeking emergency medical attention.

It's important for anyone with an Allergy, to discuss treatments with a qualified health care provider to understand how to manage individual allergies and also to set up an Allergy Action Plan in the case of a reaction.

And what about Intolerances and Autoimmune Conditions?

Intolerances are non-immune related reactions that, instead of affecting a person's immune system it affects their digestive system. Unlike allergies, intolerances can be distressing but are not life-threatening. Common intolerances include gluten intolerance, lactose intolerance, FODMAP Intolerance, MSG intolerance, Salicylates intolerance, etc.

The symptoms from an intolerance may be:

• Metabolic (e.g. enzyme deficiency, carbohydrate malabsorption)
• Pharmacologic (e.g. chemical sensitivity)
• Toxic (e.g. poison, toxins)
• Adverse (e.g. preservatives, benzoates)

A general course of treatment for intolerance reactions ranges across various prescribed, and over-the-counter medications that may also include but are not limited to immediate dietary and lifestyle changes.

It's important for anyone with an Intolerance, to discuss treatments with a qualified health care provider to understand how to manage individual intolerance and also to set up an Intolerance Action Plan in the case of symptoms.

Unlike allergies and intolerances, autoimmune conditions are reactions where the body's immune system attack healthy cells in its own body. For instance, when a person with Coeliac disease ingests gluten, their immune system may react by mounting an attack against the body's own healthy cells, damaging the stomach lining and leading to medical complications. And with repeated exposure and reactions, a Coeliac person may experience the effects of malabsorption, which prevents absorption of some nutrients.

Common autoimmune conditions include Coeliac disease, Hashimoto thyroiditis, Type 1 diabetes, Addison disease, etc.

If you think you may have an allergy, intolerance and/or autoimmune condition, before any treatment it's important to seek diagnosis, examination and advice by a qualified health care provider.

9 Common Groups

We have categorised allergies into 9 common groups that also take into consideration intolerances and autoimmune conditions.
Click on any group below to learn more.

Food Allergies


Skin and Allergies


Pollen Allergies


Latex Allergies


Pet/ Animal Allergies


Insect Allergies


Drug Allergies


Mould Allergies


Dust Mite Allergies


The information provided on Allergy Life Australia is to generally educate and inform you about living with allergies, intolerances and conditions, and is not intended as medical instruction or as a substitute for diagnosis, examination and advice by a qualified health care provider.