Allergic Conjunctivitis

What is allergic conjunctivitis?

When your eyes are exposed to substances like pollen or mold spores, they may become red, itchy, and watery. These are symptoms of allergic conjunctivitis. Allergic conjunctivitis is an eye inflammation caused by an allergic reaction to substances like pollen or mold spores.

The inside of your eyelids and the covering of your eyeball have a membrane called the conjunctiva. The conjunctiva is susceptible to irritation from allergens, especially during hay fever season. Allergic conjunctivitis is quite common. It’s your body’s reaction to substances it considers potentially harmful.

What are the types of allergic conjunctivitis?

Allergic conjunctivitis comes in two main types:

Acute allergic conjunctivitis

This is a short-term condition that is more common during allergy season. Your eyelids suddenly swell, itch, and burn. You may also have a watery nose.

Chronic allergic conjunctivitis

A less common condition called chronic allergic conjunctivitis can occur year-round. It is a milder response to allergens like food, dust, and animal dander. Common symptoms come and go but include burning and itching of the eyes and light sensitivity.

What causes allergic conjunctivitis?

You experience allergic conjunctivitis when your body tries to defend itself against a perceived threat. It does this in reaction to things that trigger the release of histamine. Your body produces this potent chemical to fight off foreign invaders. Some of the substances that cause this reaction are:

  • household dust
  • pollen from trees and grass
  • mold spores
  • animal dander
  • chemical scents such as household detergents or perfume

Who is at risk for allergic conjunctivitis?

People who have allergies are more likely to develop allergic conjunctivitis. According to the Asthma and Allergy Foundation of America, allergies affect 30 percent of adults and 40 percent of children, and often run in families.

Allergies affect people of all ages, though they are more common in children and young adults. If you have allergies and live in locations with high pollen counts, you are more susceptible to allergic conjunctivitis.

How is allergic conjunctivitis diagnosed?

Your doctor will examine your eyes and review your allergy history. Redness in the white of the eye and small bumps inside your eyelids are visible signs of conjunctivitis. Your doctor may also order one of the following tests:

  • An allergy skin test exposes your skin to specific allergens and allows your doctor to examine your body’s reaction, which may include swelling and redness.
  • A blood test may be recommended to see if your body is producing proteins, or antibodies, to protect itself against specific allergens like mold or dust.
  • A scraping of your conjunctival tissue may be taken to examine your white blood cells. Eosinophils are white blood cells that become activated when you have allergies.