Not bacteria or viruses. So it can’t spread from one person to another, in other words it’s not contagious pink eye. Either way, it’s important not to touch or rub your eyes as this could irritate them more.

In this article we discuss the symptoms and causes of allergic pink eye. Later we talk about how allergic pink eye is diagnosed and treated.

Symptoms of pink eye can differ depending on if it’s caused by allergies or a viral or bacterial infection. However, overlapping symptoms include itching, red and watery eyes.

If you have allergic pink eye, both eyes are normally affected and are usually bloodshot. You may also experience intense itching in or around the eyes. Other symptoms can include a runny nose. Generally, this means you’re experiencing an allergic reaction rather than a bacterial or viral infection. Usually, initial symptoms, such as watery discharge and redness of the eye appear within 20–30 minutes of encountering the allergen.

Because there are different types of allergic pink eye, some people can experience additional symptoms, including:

• Eye pain (burning eyes or a stinging sensation)
• Blurred vision
• Swollen eyelids
• A gritty feeling in the eye (foreign body sensation)
• Light sensitivity (photophobia)
• Corneal ulcers
• Lumps and swelling on the inner eyelids

With bacterial conjunctivitis you may notice a more yellowish-white discharge and that your eyelids are very sticky. Sometimes your eyelids may even stick together. This is likely to happen in the morning when you first wake up. Viral conjunctivitis shares similar symptoms but typically has watery discharge instead. Some viruses that cause pink eye are spread by mosquito and tick bites, so it’s important to take care when travelling to tropical or subtropical regions.

If you’re also experiencing a headache or feel nauseous you should see a doctor so they can rule out more serious conditions.

If you’re allergic to tree pollen you’ll likely notice symptoms easing on their own when the tree pollen count is low. Yet with other types of allergic pink eye, conjunctivitis symptoms can persist all year round, unless you receive treatment. Especially if they’re caused by indoor allergens or a foreign object, for example contact lenses.

No matter what type of allergic pink eye you have, on your first meeting your doctor will likely talk about how to practice eye care to reduce symptoms.

Typical eye care advice includes:

• No eye rubbing
• Using artificial tears (lubricating eye drops)
• Applying a cold compress to the eyes
• Avoiding trigger allergens

They may also suggest taking over-the-counter antihistamines as an initial treatment option. Particularly for when you can’t avoid allergens or irritants. Don’t forget, that anything in the eye can irritate it. So, if you usually wear contact lenses and they're causing eye redness and other symptoms, try to wear glasses instead.

Sometimes your symptoms may persist. And when this happens, your doctor may refer you to a specialist who will investigate your allergy further. If your allergic pink eye is severe, they may prescribe corticosteroids or medication that suppresses your immune system.

Allergy immunotherapy could also be an option for some people.  This type of treatment aims to retrain your body to get used to the allergen that’s causing symptoms. Over a period of time, you’re given controlled and repeated doses of the allergen. Its goal is to target the cause of the allergy, not just the symptoms.

This option is only available to people whose allergies are caused by IgE antibodies, so may be more suited to people with seasonal and perennial conjunctivitis.

Before a doctor diagnoses you with allergic pink eye, they’ll most likely ask you questions about your health history. They do this to narrow down any potential allergens you’ve encountered. Additionally, they’re also making sure you don’t have viral pink eye or bacterial pink eye.

To confirm if any allergens are causing your pink eye symptoms, they might recommend a skin prick test or patch test. Sometimes the results suggest more than one allergen could be responsible. When this happens, you may need to undergo a conjunctival allergen provocation test (CAPT). This is also called a conjunctival allergen challenge (CAC).

During this test, increasing amounts of the suspected allergen, for example pollen, are applied to the eye. If you begin to feel any symptoms, such as itching or tearing up you likely have an allergy.