Pink Eye vs. Allergies: Understanding the Difference

Close-up of a person's eye. The eye looks very inflamed and irritated. It is red and puffy.
  • Pink eye is a viral or bacterial infection. It typically causes irritation, swelling, and pain in the affected eye.
  • An allergic reaction occurs when the immune system has an extreme response to a substance.
  • Pink eye and allergies have similar symptoms including inflammation, itchiness, swelling, and watery eyes. Knowing the key differences can help you get the right treatment.
  • Both conditions are treatable with over-the-counter and prescription medications, lifestyle changes, and preventative steps. Although symptoms may go away on their own, leaving them untreated can cause serious, long-term damage.

Pink eye and allergies are two common conditions that affect many Americans in their lifetime.

Around 6 million people in the U.S. develop pink eye each year, and 60 million are affected by allergies.

Both conditions cause the eyes to become dry, itchy, red, and irritated.

Although these conditions are rarely life-threatening, they can both cause frustration and discomfort.

Because pink eye and allergies have similar symptoms, telling them apart can be challenging. However, it’s essential to know the differences as it will help you get the right treatment.

This article takes a closer look at the key differences between pink eye and allergies as well as the different causes and treatment options to help you manage your symptoms.

What is Pink Eye?

Pink eye — also known as conjunctivitis — is an infectious, inflammatory condition caused by bacteria or by the same virus that causes the common cold.

This condition commonly occurs along the transparent membrane of the eye — called the conjunctiva — that covers the white part of your eyeball.

The infection causes the blood vessels in this membrane to become inflamed and red, making them appear more visible.

Pink eye is highly contagious and can spread quickly in close-contact environments like schools and workplaces.

What are the different types of pink eye?

There are three different types of pink eye infections. Although they are likely to have similar symptoms, their causes aren’t the same and they might need to be treated slightly differently.

Allergic conjunctivitis

This condition occurs among people who already suffer from seasonal allergies.

When they come into contact with something that triggers their allergies, they might develop allergic conjunctivitis in their eyes.

Giant papillary conjunctivitis

This is a type of allergic reaction to the chronic presence of a foreign body in the eye, often caused by contact lenses that aren’t replaced often enough.

People who don’t follow contact lens care instructions properly, have an exposed suture after surgery, or are fitted with a prosthetic eye, are at a higher risk of developing this condition.

Infectious conjunctivitis

This type of pink eye is caused by a viral or bacterial infection that was transferred to the eyes from somewhere else. Bacteria usually come into contact with the eyes as a result of touching infected areas or objects like ears, nose, respiratory discharge, or fecal matter.

Infectious pink eye is highly contagious and can be spread to a number of people quickly if proper care isn’t taken.

Viral conjunctivitis

This is the most common form of pink eye, and it often appears alongside a cold since the same virus causes both conditions.

Viral conjunctivitis may resolve on its own within a week or two. You can also use cold compresses and over-the-counter lubricant eye drops (artificial tears) to ease any swelling or dryness.

It can progress to bacterial pink eye if a person keeps rubbing their eyes — this often introduces bacteria to the area.

Bacterial conjunctivitis

This type of pink eye is caused by a bacterial infection and can also occur alongside an ear infection.

It forms a crust along the eyelid and can also cause discharge to leak from the affected area. Both viral and bacterial conjunctivitis may create a discharge. The viral is typically watery, while the bacterial is typically thick and at times, yellowish.

Ophthalmia neonatorum

This is a severe form of bacterial conjunctivitis that usually occurs in newborn babies. It develops when babies are exposed to Chlamydia trachomatis or Neisseria gonorrhoeae as they pass through the birth canal.

If it isn’t treated immediately, ophthalmia neonatorum can cause permanent eye damage.

Chemical conjunctivitis

Also known as toxic pink eye, chemical conjunctivitis develops when the eye is exposed to smoke, liquids, fumes, or chemicals.

It can also be caused by frequent exposure to chlorine in swimming pools.

The eye typically needs to be flushed with running water immediately to remove the toxic liquid. If left untreated, this condition can cause severe damage to the eye.

Causes of pink eye

Pink eye can be caused by a number of factors. These include:

  • Bacterial or viral infections that spread from somewhere else, usually from respiratory illnesses like the common cold
  • Blocked tear ducts
  • Chemicals
  • Dirty contact lenses
  • Pollution
  • Amoeba and other parasites

This condition is highly contagious and can be spread easily without the proper precautions.

A close-up of a woman putting a contact lens into her right eye.

Common symptoms of pink eye

Symptoms of pink eye can vary slightly, depending on the type you have. Common symptoms for viral and bacterial infections include:

  • Eyes that appear pink or red in color
  • Gritty or itchy sensation in the eye
  • Watery eyes
  • Burning sensation
  • Frequent urge to rub the eyes to minimize itchiness
  • Discharge (usually in bacterial infections)
  • Swollen and crusty eyelids
  • Sensitivity to light
  • Blurred vision

Some of these symptoms may resolve without treatment but others require medical attention.

It’s recommended to speak to your doctor if you’re unsure of available treatment options that can help alleviate discomfort.

How is pink eye diagnosed and treated?

Pink eye should be diagnosed by a medical professional. They will also be able to recommend the best course of action to help heal your condition.

A diagnosis is usually made during a physical exam. This is when your doctor asks you a set of questions about your symptoms and medical history while examining your eye.

They may also take a sample of the discharge from your eye, but this is rare.

Once they’ve made a diagnosis, your healthcare provider may recommend the following treatment options:

  • Antibiotic eye drops and ointments
  • Wet or cold compresses to help with pain and swelling
  • Eye drops
  • Removing irritants like contact lenses

They may also recommend pain relievers and anti-inflammatories to help alleviate secondary symptoms.

How can I avoid getting pink eye?

Although pink eye can be highly contagious, it’s also easy to prevent your eyes from becoming infected or spreading the condition to other people.

The following steps can help you protect yourself from pink eye:

  • Wash your hands with soap and water, especially after being in contact with someone who has pink eye.
  • If you have pink eye, avoid touching or rubbing your infected eye. This can worsen the irritation and even spread the infection to your other eye.
  • Avoid sharing items like makeup, eye drops, contact lenses, glasses, bedding, or towels.
  • Try to use different products for the infected and non-infected eyes.
  • Clean, store, and replace contact lenses as instructed. You can even try to avoid wearing them for a while to minimize irritation.
A close-up of someone's hands as they rinse them at the sink.

What Are Allergies?

Allergies occur when the immune system has an overreaction to normal substances in the environment. These may include:

  • Dust mites
  • Pollen
  • Pet hair
  • Certain foods
  • Insect venom (usually from bites and stings)

When you have an allergic reaction, your immune system starts to produce antibodies and releases histamine. These are two components that fight harmful substances.

This causes inflammation in the body, sinuses, digestive system, and airways which can lead to feelings of discomfort and pain.

Allergic reactions can be life-threatening if a person goes into anaphylactic shock — a bodily state where blood pressure drops suddenly and breathing becomes obstructed.

Common symptoms of allergies

Most allergic reactions have similar symptoms. These may include:

  • A runny nose
  • Watery eyes
  • Pain or tenderness around the sinuses
  • Coughing
  • Itchy eyes
  • Breathlessness

You may also experience some redness or irritation around the eyes, or a mild rash on affected areas of the body.

Seek emergency medical attention if you experience any of the following symptoms:

  • A swollen or blistering skin rash
  • Wheezing
  • Tightness in the chest and throat
  • Breathing difficulties
  • Swelling in the mouth, face, lips, tongue, or throat
A man in a blue t-shirt stands outside while rubbing his eyes.

How are allergies diagnosed and treated?

Allergies can be treated with over-the-counter (OTC) medicines and don’t usually require a professional medical diagnosis.

Treatment options for allergies may include:

  • Avoiding allergens where possible
  • Taking medications like antihistamines and steroid tablets or creams
  • Having emergency medical treatment like an EpiPen on hand for severe reactions

If you are concerned about any of your symptoms, make an appointment to see your healthcare provider.

Can allergies be prevented?

You can speak to your doctor about doing allergy tests to find out what you may be allergic to. This can help you to avoid these substances in the future.

An allergy testing involves the following:

  • A skin prick or patch test where small samples of different allergens are put onto your skin to see if your skin reacts to any of them.
  • Blood tests to check for any allergens in your system that may be causing your symptoms.
  • Following a specific diet to help determine if there are certain foods that you are allergic to.

Your doctor might also recommend immunotherapy — a process where you are repeatedly exposed to your allergens in a controlled environment so your body can build up a tolerance to it.

Over time, immunotherapy may help to reduce an unnecessary immune response to substances that aren’t harmful.

How Can I Tell the Difference Between Pink Eye and Allergies?

Pink eye and allergies can have very similar symptoms, making it hard to tell the difference. Here's a breakdown of the key differences:

Symptom: Itchiness
Viral Pink Eye: Yes
Bacterial Pink Eye: Yes
Allergies: Yes

Symptom: Pink or red-looking eyes
Viral Pink Eye: Yes
Bacterial Pink Eye: Yes
Allergies: Yes

Symptom: Watery eyes
Viral Pink Eye: Yes
Bacterial Pink Eye: No
Allergies: Yes

Symptom: Burning sensation
Viral Pink Eye: No
Bacterial Pink Eye: Yes
Allergies: No

Symptom: Discharge
Viral Pink Eye: No
Bacterial Pink Eye: Yes
Allergies: No

Symptom: Pain
Viral Pink Eye: Yes
Bacterial Pink Eye: Yes
Allergies: No

Symptom: Gritty sensation in the eye
Viral Pink Eye: No
Bacterial Pink Eye: Yes
Allergies: Yes

Symptom: Happens alongside another infection
Viral Pink Eye: Yes
Bacterial Pink Eye: No
Allergies: No

Symptom: Swelling and tenderness
Viral Pink Eye: Yes
Bacterial Pink Eye: No
Allergies: No

Why is it important to know the difference between pink eye and allergies?

Knowing the difference between pink eye and an allergic reaction is essential for getting the right treatment.

If conditions like pink eye are left untreated, they can lead to infections of the cornea, eyelids, and tear ducts.

In the most severe cases, this can impair your vision and cause permanent damage to your sight. However, these cases are rare.

Untreated allergies can also cause more severe reactions and attacks over time. This is because these reactions weaken your immune system and make you more prone to infection.

A weakened immune system leaves the body vulnerable to bacterial or fungal diseases that can occur in the sinuses, lungs, skin, or ears.

When Should I See a Doctor About Pink Eye or Allergy Symptoms?

Although the symptoms of pink eye and allergies may resolve without treatment, it’s always a good idea to monitor them.

If your condition doesn’t improve within one week, make an appointment to see your doctor.

Additionally, if you experience breathing difficulties, intense pain, or blistering rashes, seek emergency medical care right away.

Where Can I Learn More About Pink Eye and Allergies?

Do you have a pink eye that won’t heal? Not sure if it’s your allergies or something more serious? Head over to LifeMD and make a telehealth appointment with a board-certified doctor or nurse practitioner.

Dr. Asunta Moduthagam

Dr. Moduthagam has been a family medicine physician since 2011. She loves working with patients to help them reach an optimal state of well-being. She’s dedicated to thoughtful, compassionate care and is committed to being her patients’ best advocate.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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