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Conjunctivitis, or pinkeye, occurs when the conjunctiva of the eye becomes inflamed. The eye can become red or pink, swollen, and irritated, and there may be mucus. Infective conjunctivitis can be highly contagious.

The conjunctiva consists of a thin layer of cells, or membrane, that covers the inner surface of the eyelids and the whites of the eyes.

Inflammation causes tiny blood vessels, or capillaries, in the conjunctiva to become more prominent. This causes discomfort and a pink or red appearance that can last 1–4 weeks or longer.

Causes include irritation, allergy, and infection. This article will focus mainly on infective conjunctivitis.

There are different ways of classifying conjunctivitis.

Irritant or allergic conjunctivitis: An allergen or irritant, such as pollen or chlorine, comes into contact with the eye, triggering irritation and inflammation.

Infective conjunctivitis: Bacteria or a virus cause an infection.

Acute or chronic: In acute conjunctivitis, symptoms usually last 1–2 weeks, but they can last 3–4 weeks. Chronic conjunctivitis lasts over 4 weeks.

Here, learn more about allergic conjunctivitis.

Signs and symptoms may include the following:

  • redness, due to irritation and widening of the tiny blood vessels in the conjunctiva
  • discharge from the eye
  • a watery eye, as the tear glands become overactive
  • a sticky or crusty coating on the eyelashes, especially on waking
  • soreness and “grittiness,” which feels like sand in the eye
  • swelling due to inflammation or rubbing
  • a feeling of itching, burning, or irritation
  • discomfort when using contact lenses

If an infection is present, symptoms may affect one eye first then spread to the other. If an outside irritant, such as dust, is the cause, it will usually affect both eyes at the same time.

Depending on the cause, a person may experience other, flu-like symptoms, such as:

These may be early signs of an infection.

In newborns

Newborns often develop pinkeye. Symptoms include red, tender, and puffy eyelids.

Urgent medical attention can help prevent complications and identify and treat any underlying conditions.

Pinkeye that results from an infection can be very contagious. People can pass it on through:

  • personal contact, such as shaking hands and then touching the eyes
  • droplets in the air due to coughs and sneezes
  • touching an object where the germs are and then touching the eyes

Conjunctivitis is most likely to be contagious while symptoms are present. People should stay at home during this time.

A person should seek medical advice if they believe they have an eye infection.

They should seek urgent advice if:

  • there is severe pain
  • vision changes occur
  • the eye becomes sensitive to light
  • one or both eyes are dark red
  • there is an injury or something stuck in the eye
  • the person has a severe headache and feels sick

These symptoms may indicate a more serious condition.

Conjunctivitis can result from an allergy or a viral or bacterial infection.

Some 80% of cases result from viruses, such as:

Bacteria that may cause conjunctivitis include:

  • Staphylococcus aureus
  • Streptococcus pneumoniae
  • Haemophilus influenza

Bacterial conjunctivitis sometimes stems from a sexually transmitted infection (STI), such as chlamydia.

Can COVID-19 cause pinkeye?

In July 2020, reports of a person who tested positive for COVID-19 with conjunctivitis as their only symptom prompted suggestions that it may be evidence of COVID-19.

However, coronaviruses are not a common cause of conjunctivitis, and scientists need to carry out more research before they know the frequency of conjunctivitis as a symptom of COVID-!9.

For more news and research on COVID-19, see our dedicated hub.

Causes in newborns

Pinkeye in newborns can be due to infection, irritation, or a blocked tear duct. All causes produce similar symptoms.

The bacteria or virus that lead to these infections can transmit to the infant during delivery, even if the person giving birth does not have symptoms.

The most common bacterial cause is Neisseria gonorrhoeae, which causes gonorrhea. According to the Centers for Disease Control and Prevention (CDC), Chlamydia trachomatis can also cause it, as can the virus that leads to genital herpes, but this is less common.

The CDC also indicate that symptoms of bacterial conjunctivitis due to C. trachomatis usually appear 5–12 days after delivery. If the bacteria is due to N. gonorrhoeae, they typically appear after 2–4 days.

Pinkeye may also be a reaction to eye drops given at birth to prevent infection. In this case, the symptoms usually disappear after 24–36 hours.

Other causes of red eyes

There are many reasons for reddened eyes, such as:

Some of these conditions can lead to vision loss. Anyone who experiences symptoms that do not improve with treatment should return to their doctor.

To diagnose conjunctivitis, a doctor will:

  • look at the signs and symptoms
  • ask some questions, for example, about eye history and allergies
  • less commonly, take a swab to test for bacteria or viruses

Nearly half of infective conjunctivitis cases resolve without medical treatment within 10 days, and a doctor may suggest watching and waiting.

Several home remedies can help ease symptoms and may speed up recovery.

Manage pain: Use ibuprofen for pain.

Avoid contact lenses: Avoid using lenses while symptoms are present, then replace the lenses, lens case, and solution.

Avoid eye makeup: Avoid eye makeup during an infection and replace it with new products afterward.

Artificial tear eye drops: these can help relieve soreness and stickiness.

Artificial tear eye drops are available to purchase over the counter (OTC) or online.

Avoid red-reducing eye drops: These may make symptoms worse.

Use a washcloth soaked in warm water: Use gently several times a day to clean away discharge. Use a clean cloth for each eye.

Apply warm compresses: These can soothe discomfort. Soak a clean, lint-free cloth in warm water, wring it out, then apply gently to the closed eye.

Avoid spreading the infection by:

  • changing pillowcases and towels every day
  • avoiding touching the eyes and face
  • not sharing washcloths and other personal items
  • washing the hands frequently

Some people suggest applying breast milk to the eyes, but the American Academy of Ophthalmology say there is no evidence that this helps, and it may be dangerous.

In most cases, conjunctivitis goes away without medical treatment. If the cause is viral, a doctor will recommend treating the symptoms with home remedies. If it relates to an allergy or irritant, the person should also try to avoid the substance that causes the reaction.

If the doctor suspects a bacterial infection, they may recommend antibiotics. Some doctors prescribe antibiotic eye drops or other preparations just in case, but it is not certain that these will help.

Antibiotics will not help manage a viral infection.

Return to the doctor if symptoms do not improve with treatment or if there is pain or blurry vision.

In newborns

In many states, a doctor will put antibiotic drops or ointment in all newborns’ eyes to prevent conjunctivitis.

If necessary, a doctor will prescribe treatment. This may include:

  • antibiotics, which may be oral, intravenous, drops, or ointment
  • gently applying a warm compress to relieve swelling and irritation
  • rinsing the eyes gently with a saline solution
  • a gentle, warm massage for a blocked tear duct

Take care to follow the doctor’s instructions for managing newborn conjunctivitis. Always wash the hands well before and after using any treatment.

Eye drops or eye ointment are for putting straight onto the eye. The dosage depends on the type. Some people may find ointments easier to use than eye drops with an infant or young child.

Avoid touching the eye with the dropper or sharing eye drops with others, as this may pass on the infection.

Vision can become blurry shortly after using eye drops. Make sure you can see clearly before driving or operating machinery.

People can lower their risk of contracting or transmitting infective conjunctivitis by:

  • not touching or rubbing the eyes
  • washing the hands frequently or using hand sanitizer
  • always removing contact lenses at night and following all lens hygiene instructions
  • keeping eyeglasses clean
  • not sharing personal items, such as towels and makeup
  • using goggles in a swimming pool
  • not swimming while an infection is present

Ways of reducing the risk of irritant and allergic conjunctivitis include:

  • ventilating rooms effectively
  • regularly cleaning and maintaining air conditioning units
  • avoiding smoky atmospheres

What is the correct way to wash hands? Find out here.

Conjunctivitis does not usually lead to complications. However, it can be a symptom of a more serious condition.

A person with severe or persistent symptoms should seek medical attention to reduce the risk of further problems.

In newborns

Most infants make a full recovery from infective conjunctivitis with no complications.

However, infective conjunctivitis can sometimes be severe and progress rapidly in newborns. In very severe cases, it may affect vision.

If an STI is present, other complications can arise.

For example, without treatment, 10–20% of newborns with infective conjunctivitis due to C. trachomatis will also develop pneumonia, which can be life-threatening.

Pinkeye can result from many causes. Infective conjunctivitis can be highly contagious.

Home and OTC remedies are the most common treatments, and most cases pass without prescription drugs. Antibiotics will only help if a bacterial infection is present.

To prevent transmission, people should practice good hand washing and avoid touching the eyes and face.