7 minute read

Guide to Allergies: Symptoms, Causes and Treatments

Written by
Reviewed by
Dr. Joseph Santos & Dr. Ai Nhi Bui

Allergies affect so many of us, from seasonal allergies in the springtime to pet and food allergies. One of the most common types of allergies in Australia is hay fever; in fact, 1 in 5 Australians suffer from hay fever either seasonally or throughout the year. But only 16.5% of people choose the appropriate allergy medications and treatments for their symptoms. We dive into the different types of allergies, causes, symptoms and available treatments in our guide.

Table of Contents:

  • What are allergies? 
  • Types of allergies and causes
  • Allergy symptoms
  • Allergy medications and treatments
  • Frequently asked questions about allergies

What are allergies?

It’s quite common for people to have a reaction to something and say that they are allergic to it. The definition of allergies is when your immune system has a response to a foreign substance, also known as an allergen, that doesn’t cause a response in most people. 

These allergens can be things like pollen, dust, mould, grass, bee venom, pet dander, chemicals and other irritants. 

The immune system produces antibodies. If you have allergies, your immune system recognises these allergens and thinks that they are dangerous. It will start attacking them, potentially causing an immune reaction that ranges from mild to severe from person to person.

Anaphylaxis is a very serious allergic reaction that can be life-threatening. The reaction can occur within seconds or minutes of exposure to the allergen and should always be treated as a medical emergency. People with severe allergies often need to have epinephrine pens with them in case of anaphylaxis.

Types of allergies and causes

There are many different types of allergies and symptoms in an allergic reaction that range in severity from person to person. 

Hay fever (allergic rhinitis)

Allergic rhinitis, commonly known as hay fever, is a type of allergy response that can cause a range of symptoms including runny nose, itchy nose, sneezing, itchy eyes, watery eyes, itchy, irritative cough, nasal congestion, cloudy and fogginess. This can be seasonal, particularly in the spring, summer or early fall, or perennial, meaning the symptoms are present year-round. Hay fever is a term often used to describe a variety of allergies to outdoor allergens like pollen, grass and trees, indoor allergens like pet dander, dust and mould or irritants like cigarette smoke, exhaust and perfumes. 

Hay fever symptoms

Dust allergy

Dust allergies are quite common and can be triggered by dust mites, the tiny bugs that commonly live in house dust. They are too small to see without a microscope and thrive in warm, humid environments. They are particularly common in items like bedding, furniture and carpet. 

Pet allergy

Pet allergies, particularly toward dogs and cats, is a very common allergy. The allergens from dogs and cats can come from their hair, fur, saliva or urine. It is possible for pollen and dust on the animal’s coat to cause allergies as well; in these instances, the allergy is towards the dust or pollen, not to the pet. Highly sensitive people can start to experience symptoms within minutes of touching a dog or cat or entering a house with a pet. 

Mould allergy

Mould lives on many surfaces, from outside on logs and leaves to indoors in kitchens and bathrooms. Oftentimes mould is not visible to the naked eye, and the tiny mould spores can become airborne and cause allergic reactions. 

Insect sting or bite allergy

Being allergic to bees, spiders and other insects that sting or bite is another common allergy. While the aforementioned allergies typically cause symptoms related to the nose and eyes, insect allergies cause pain, swelling, hives, itching and potentially anaphylaxis depending on the severity of the allergy. People who have a serious allergy to insects often need to have an epinephrine pen with them in case symptoms of anaphylaxis develop. 

Drug allergies

Different types of drugs and medications can also cause allergic reactions. Some common drug allergies include penicillin and other antibiotics in the penicillin family, antibiotics containing sulfonamides (also known as sulfa drugs), anticonvulsants, aspirin, ibuprofen and other nonsteroidal anti-inflammatory drugs (also known as NSAIDs) and chemotherapy drugs. 

Latex allergy

Natural rubber latex that comes from the sap of the rubber tree Hevea brasiliensis is used to make many commonly used items, such as rubber latex gloves, syringes, bandages, dressings, condoms, tires, balloons and more. People who have a latex allergy are allergic to this natural rubber latex, not the synthetic rubber latex that is found in “latex” house paints and other products.

Food allergy and intolerance

Food allergies can appear at any age; it’s possible for adults to develop allergies to foods that they’ve been eating for many years. While any food can cause an adverse reaction, the following eight types of foods account for about 90% of all reactions: eggs, milk, peanuts, tree nuts, fish, shellfish, wheat and soy. 

It’s important to note the difference between an allergy and an intolerance. A food allergy causes an immune system reaction that can affect multiple organs within the body and can be severe or life threatening. A food intolerance is usually due to the body’s inability to completely break down or digest the food component. It only causes symptoms when consumed in higher quantities and does not trigger an immune response from the body. 

Allergy symptoms

Depending on what kind of allergies you have, there are a variety of symptoms you might experience. 

Hay fever symptoms as well as mould, dust and pet allergy symptoms include: 

  • Sneezing
  • Itching of the nose or eyes
  • Runny nose
  • Watery, red or swollen eyes

Insect allergy symptoms can range from mild to severe and life threatening. Mild insect allergy symptoms can include:

  • Swelling, redness or pain at the site of the sting or bite
  • Itching or hives anywhere on the body

Severe and potentially life-threatening insect allergy symptoms can include:

  • Coughing, tightness of the chest, wheezing or shortness of breath
  • Significant swelling of the eyes, lips, throat or face 
  • Anaphylactoid and anaphylaxis reactions

If you experience any of the above symptoms, call an ambulance for immediate medical review.

Drug allergy symptoms include:

  • Itchy skin, rash or hives
  • Facial swelling
  • Wheezing
  • In serious cases, anaphylaxis

Food allergy symptoms include:

  • Tingling in the mouth
  • Swelling of lips, tongue, face or throat
  • Hives
  • In serious cases, anaphylaxis

Allergy medications and treatments

Because allergic reactions are caused by specific allergens, it’s best to try to minimise exposure to the allergens to reduce the symptoms. Identifying the triggers and making lifestyle modifications to avoid them can help you manage your symptoms. There are a variety of allergy medications and treatments from over-the-counter (OTC) options like antihistamines and eye drops to stronger prescription medications like intranasal steroidal sprays and eye drops if your symptoms require them.

If you have hay fever symptoms, you can get medications and treatments online through Rosemary. Fill out a text-based assessment and an online doctor will review within hours and prescribe a personalised treatment plan for you. Your medication is delivered with free shipping anywhere in Australia.

Frequently asked questions about allergies

Are allergies genetic?

Developing allergies is often hereditary, meaning if either of your parents have allergies to anything, it’s likely that you may have allergies as well. Similarly, if you or your partner have allergies, it’s likely that your children will also develop allergies. However, it’s not guaranteed that allergies will be passed down from generation to generation. It’s also important to note that people don’t usually inherit specific allergies, but rather the likelihood of having allergies in general.

Are allergies contagious?

While allergic symptoms often include similar symptoms to colds and flus like sneezing, runny nose and sinus congestion, allergies are not contagious. The common cold virus causes additional symptoms like coughing, fevers and sore throats. Contrary to the name, hay fever does not cause fevers and rarely causes coughing. 

What are seasonal allergies?

Seasonal allergies are allergies that come about during certain times of the year, particularly during the spring, summer and early fall. They occur because this is when trees, grasses and weeds release pollen in the air and outdoor moulds release their spores into the air. These allergens can sometimes be captured in the wind or into hair and clothing which can trigger symptoms as well.

Allergy treatment online with Rosemary Health

Whether you have seasonal allergies or experience them year-round, you can help manage your symptoms by identifying the correct allergy treatment and medication. While allergies are not curable, a Rosemary online doctor can help - simply fill out a 100% online, text-based assessment, a licensed Australian doctor will review within hours and, if suitable, prescribe a personalised treatment plan for you. Start your online visit for allergy treatment today


Why choose Rosemary?

We created Rosemary to start a revolution. We want all Aussies to get quality and accessible care anytime, anywhere.
In person
No booked out appointments.
From the comfort of your own home.
Medication straight to your door.
900+ branded & generic medications.
Unlimited doctor and nurse aftercare messaging.
Automatic refills and treatment deliveries.