An Introduction to Allergic Conjunctivitis & It’s Common Causes

Eye Health Articles

Exposure to allergens such as pollen and mold spores may make your eyes become red, itchy, and watery. These are all symptoms of allergic conjunctivitis.

Allergic conjunctivitis is an eye inflammation induced by allergens such as the ones listed above. The name comes from the membrane inside of your eyelids and the covering of your eyeball which is called conjunctiva. Allergic conjunctivitis is extremely common as the conjunctiva is very susceptible to allergens.

For information on conjunctivitis (pink eye), read through our article.

Allergic Conjunctivitis Comes in Two Types

There are two main types of allergic conjunctivitis: acute allergic conjunctivitis and chronic allergic conjunctivitis.

  • Acute allergic conjunctivitis is a short-term condition that is most common during allergy season. With acute allergic conjunctivitis, your eyelids will swell, itch, and burn. Those with acute allergic conjunctivitis may also experience a runny nose.
  • Chronic allergic conjunctivitis is a less common condition that may occur year-round. It tends to be a milder response to allergens, with symptoms such as burning and itching of the eyes and light sensitivity.

Allergies Often Run in Families

People who have allergies are more likely to develop allergic conjunctivitis. A study shows that 30% of adults and 40% of children are affected by allergies.

Allergies can be passed down through generations of family. They affect people of all ages, though mostly common in children and young adults.


Symptoms of allergic conjunctivitis include:

  • Red eyes
  • Itchy eyes
  • Watery eyes
  • Burning eyes
  • Puffy eyes

Although symptoms of allergic conjunctivitis, it is possible these symptoms may be caused by another eye condition, or health related issue. As such, it is important to schedule an appointment with our optometrist to have the cause of your symptoms accurately diagnosed.


Our optometrist will examine your eyes and review any allergy history. Our optometrist may order an allergy skin test to determine which allergens your body reacts to.

A blood test may be required in order to determine if your body is producing adequate proteins and antibodies to protect itself against specific allergens.

Common Causes of Allergic Conjunctivitis

When you are experiencing allergic conjunctivitis, your body is trying to defend itself against a harmful threat. This occurs when something triggers the release of histamine, forcing the body to produce the chemical to protect itself from the threat.

Allergic conjunctivitis can be caused by any allergens, such as:

  • Household dust
  • Pollen
  • Mold spore
  • Chemical scents

Allergic conjunctivitis may also be caused by a reaction to certain medications or substances that make contact with the eyes. A common substance that causes allergic conjunctivitis is contact lens solution (especially when contaminated) and medicated eye drops.


Although it is extremely difficult to avoid all allergens that may cause allergic conjunctivitis, the best thing you can do is limit your exposure to them. For example, if you know that you are allergic to pollen, wear a face mask and protective eyewear when outside during allergy season.

Treating Your Allergic Conjunctivitis

Oral antihistamines are available over-the-counter that reduce or block histamine release, providing relief from allergic conjunctivitis. The downside of oral antihistamines is that they tend to dry out your eyes and are not as effective as topical antihistamines. Unfortunately, you need a prescription for topical antihistamines.


If over-the-counter medications are not strong enough to provide you with the relief you seek, schedule a consultation with our optometrist. You may require a prescribed medication to ease your symptoms.

Our staff is equipped to provide both professional and friendly service for all your eye care needs.