Allergic Conjunctivitis (Pink Eye)

What is allergic conjunctivitis?

Allergic conjunctivitis (kuhn·juhngk·tuh·vai·tuhs) is an infection of the eye caused by allergens. Conjunctivitis, or pink eye, is inflammation of the conjunctiva. The conjunctiva is a thin, clear membrane that covers the white part of the eyeball (the sclera) and the inside of the eyelid. A virus, bacteria, and chemical irritants can also cause conjunctivitis.

Anatomy of the human eye relevant to viral, bacterial, and allergic conjunctivitis (pink eye), emphasizing areas such as eyelid, sclera, cornea and conjunctiva.

Anatomy of the human eye, showing the conjunctiva

What causes allergic conjunctivitis?

Allergens are substances that cause allergies. Common allergens include pollen, cosmetics, fragrances, detergents, dust mites, smoke, and pets dander. People who have allergic conjunctivitis may also have asthma and other allergy symptoms like nasal congestion and sneezing.

Most allergic conjunctivitis is seasonal. Symptoms may come and go. Other people may have symptoms all year, especially if they are allergic to indoor allergens like dust mites and pet dander or they are allergic to fragrances or detergents.

Allergic conjunctivitis can make your eyes feel uncomfortable. Most of the time, it will not harm your vision unless it is very severe and if you have it for a long time. Chronic or severe allergic conjunctivitis can damage the cornea. The cornea is the clear part of the eye covers the iris and pupils.

Other types of allergic conjunctivitis:

  • Atopic keratoconjunctivitis is a severe type of allergic conjunctivitis that usually affects people with asthma (a condition that makes breathing difficult), atopic dermatitis (a type of eczema that causes red, scaly, irritated skin), or a family history of atopic dermatitis.
  • Vernal keratoconjunctivitis is another severe type of chronic allergic conjunctivitis. It is more common in males and often occurs in persons who also have asthma or eczema.

What are the symptoms of allergic conjunctivitis?

Symptoms of allergic conjunctivitis usually affect both eyes and can include:

  • Itchy eyes
  • Watery eyes
  • Moderate redness of the eye
  • Inflammation, swelling, and itching of the eyelids and the skin around the eyes
  • Nasal discharge, head congestion, and sneezing
An illustration of a human eye showing symptoms of allergic conjunctivitis (pink eye), including redness and watery eyes.An illustration of an eye affected by allergic conjunctivitis (allergic pink eye), showing redness and watery eyes

How is allergic conjunctivitis diagnosed?

It is not necessary to visit your eye doctor at first symptoms of eye irritation, you should make an appointment with your eye doctor or primary care provider if your symptoms continue for more than 2 weeks even after using over-the-counter medications. If your symptoms occur often, see your eye doctor.

Your doctor can diagnose allergic conjunctivitis based on your symptoms and through an eye exam.

During the exam, the doctor will:

  • Take your health history
  • Check your visual acuity (test how well you can see through your central vision in each eye with an eye chart)
  • Examine the front of your eye (including your cornea)

If needed the doctor may recommend testing for allergies to identify the cause. The doctor will determine the best treatment for you.

How is allergic conjunctivitis treated?

There are many simple things you can do to reduce the symptoms of allergic conjunctivitis:

  • Avoid allergens. Keep a journal of all your exposures when your symptoms are worse. Include any facial products and detergents you may have been exposed to recently
  • Keep your windows closed and use air conditioning or an air purifier
  • Wear sunglasses outside to keep allergens away from your eye
  • Wash your hands after contact with allergens like pollen or pets
  • Wash your sheets and towels often to keep dust mites away. Always use fragrance free and hypoallergenic detergents
  • If you are allergic to mold, reduce the humidity in your home
  • Do not rub your eyes
  • Cool compresses may help with eye discomfort
  • Over-the-counter artificial tears create a barrier between the eye and the allergen. They also help flush allergens from the eye
  • Do not use contact lenses until your conjunctivitis has completely cleared
  • Avoid sharing cosmetics, especially brushes, mascara, and eye shadows

Some people may need medication to help reduce symptoms from allergic conjunctivitis.

Over the counter medications:

  • Artificial tear eye drops (talk with an eye care provider to learn which type of artificial tears might be right for you)
  • Antihistamine eye drops (do not use any eye drops for “red eye,” instead, look for drops specifically for allergies)
  • Oral antihistamines (these may make you sleepy and can sometimes worsen dry eye)

Prescription medications:

  • Eyedrops (decongestant, antihistamine, mast cell stabilizer, corticosteroid, NSAID)
  • Allergy shots (immunotherapy)
  • Non-sedating oral antihistamines (They will not make you sleepy. They may dry your eyes and make your symptoms worse)

Questions to ask your doctor

  • What causes my conjunctivitis?
  • How do I figure out what allergens are causing my conjunctivitis?
  • What can I do to relieve my symptoms?
  • When and how often do I need to take medications?
  • Should I get tested for allergies to find out the cause?
  • When is it safe to wear contact lenses again? (if you use them)

Resources

Tips and a how to video for taking eye drop medications

a woman taking eye drop medicine