Allergy Basics

Fluffy kittens, lush lawns and shady trees are just some of the simple pleasures in life which can cause your allergy symptoms to flare up. Therefore, it is important for you to identify the causes of your allergy and what to do about them, so you can enjoy more of the world around you.

Allergy Basics

Fluffy kittens, lush lawns and shady trees are just some of the simple pleasures in life which can cause your allergy symptoms to flare up. Therefore, it is important for you to identify the causes of your allergy and what to do about them, so you can enjoy more of the world around you.

What are Allergies?

An allergy occurs when the immune system attacks foreign substances that are otherwise safe, mistaking these substances for dangerous intruders in the body. These typically harmless substances are also known as allergens.

What are the common causes of allergic reactions?

The culprit behind your allergic reactions, allergens can be found aplenty within the home as well as in outdoor settings. The most common allergens include1:

Outdoor Allergens

Indoor Allergens

Exposure to these substances trigger allergic reactions in susceptible individuals, especially when these substances can be found in high concentrations within the immediate environment.


What Happens During an Allergic Reaction?

Allergens can enter your body when you take a breath, or when you rub your nose or eyes, and cause your immune system to trigger a hypersensitive reaction.

In order to get rid of the allergens that your body perceives to be harmful, your immune system produces antibodies , such as the inflammatory mediator known as histamine .

When the mast cells in your body release histamine, it triggers an allergic reaction which includes symptoms such as runny nose, sneezing, itchy eyes or nose, allergy cough, nasal congestion, and sinus pressure 2.

Outlined lightbulb with rays of light


To rid itself of an allergen , or allergens, your body experiences a number of allergic reactions which, collectively, are known as an allergic cascade. This causes your body to then release a few different inflammatory mediators. If an allergen, or allergens, enter your body, the mast cells in your body will then release an inflammatory mediator known as histamine . Histamine attaches to the receptors on blood vessels, causing them to dilate. In addition to that, histamine also binds to other receptors located in the nasal tissues, causing allergy symptoms which include swelling, as well as an itchy and runny nose.3

How Antihistamines Help Reduce Allergy Symptoms

Antihistamines such as Clarityne® (loratadine) are able to mitigate the allergic cascade triggered by an allergen , or allergens.

As the term itself suggests, an antihistamine is a substance that blocks the effects of the histamines released by your immune system . Antihistamines do this by keeping histamines from attaching to histamine receptors on cells, thus keeping them from triggering allergy symptoms.

Clarityne® provides fast-acting, non-drowsy allergy relief from over 200 allergens4 and can keep the following allergy symptoms at bay:

  • Sneezing
  • An itchy, runny, or stuffy nose
  • Red, irritated, watery eyes
  • Redness, bumps, hives , rash or itching on skin

As the #1 Allergy brand in the world6, Clarityne® provides a portfolio of allergy solutions to meet the different allergy needs of the family. Ranging from Clarityne® tablets to syrup and sprays, both adults and kids can live free from allergies and enjoy experience life like you don’t have allergies.

How Are Allergies Diagnosed?

In some cases, it is easy to determine the triggers of an allergic reaction. If you notice yourself sneezing frequently in a dusty room, you can safely surmise that you’re allergic to dust mites . When you notice your symptoms flaring up in the company of dogs and cats, then that likely means that you’re allergic to pets and their dander.5

But if you’re unsure as to what the cause of your allergy is, you can opt to do an allergy test.

Reducing Your Exposure to Airborne Allergens

The rule of thumb is always to minimise your exposure to allergens.

Various factors contribute to the ideal indoor and outdoor conditions that allow for allergens to thrive. Here’s what you can do to reduce your exposure to these allergens effectively.

    Outdoor allergies can occur throughout the year in Singapore, especially with the abundance of hot and humid weather and lots of rainfall year-round. Various allergens thrive in this climate. When you spend a fair amount of the day outdoors, you can be exposed to pollen , mold , and haze.
    1. Mask up
      To prevent yourself from inhaling these particles, wear a mask with the right fit over both your nose and mouth.
    2. Keep the windows up
      If you’re driving, keep the car windows rolled up and the air-conditioner set to “air recirculation.”
    3. Clean up
      When you get home from a day outdoors, be sure to remove your shoes, wash your face and hands or take a shower, and change your clothes to keep particles of pollen, mold, or haze from entering or lingering in your home.

    Indoor allergies can flare up at any time of the year, but they may be more frequent during the monsoon season, when people spend more time indoors.
    1. Keep a tidy home
      You can reduce the allergens within your home simply by keeping your home tidy. Use high-performance vacuum cleaners with HEPA filters that can get rid of dust mites, pet dander, mold spores, and pollen from the floor as well as on upholstered furniture. Wipe down surfaces and mop the floor with an effective cleaning agent. Wash your sheets, blankets, drapes, and upholstery regularly.
    2. Keep moisture out
      Use a dehumidifier to keep humidity levels below 50% in your home. Lower humidity levels prevent dust mites as well as mold growth. Keep the windows shut anytime the local weather report indicates high levels of humidity.
    3. Clear the air
      Keep the air clean. You can opt to use an air purifier that can filter out allergens from the air. Make sure the rooms in your home have proper ventilation. Replace the air-conditioner filter regularly. 



  1. Allergies - NHS UK, Accessed November 5, 2021
  2. Indoor Air Pollutants and Toxic Materials - CDC, Accessed November 5, 2021
  3. Antihistamines - American Osteopathic College of Dermatology, Accessed November 5, 2021
  4. Bousquet J, Khaltaev N, Cruz AA, et al. Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 Update (in collaboration with the World Health Organization, GA2LEN* and AllerGen **). Allergy . 2008; 63 (86): 8–160.
  5. How does a Doctor diagnose an Allergy?. Accessed 4 March 2022
  6. Nicholas Hall Global OTC DB6 Database. Accessed 17 February 2022.