Conjunctivitis, infective

The white part of your eye and the inner surfaces of your eyelids are covered by a transparent membrane (thin layer of cells) known as the conjunctiva. If the conjunctiva becomes inflamed, you have a condition called conjunctivitis.

There are three types of conjunctivitis: irritant, allergic, and infective. Each type of conjunctivitis is caused by different factors.

Irritant conjunctivitis

Irritant conjunctivitis occurs when an irritant such as chlorine or an eyelash gets into your eyes. This can make your eyes sore, and if you rub them it can irritate them more. Avoiding the irritant and not rubbing your eyes will help. However, if your eyes are very red and painful, you should seek medical help immediately.

Allergic conjunctivitis

Allergic conjunctivitis occurs when your eye comes into contact with an 'allergen'. An allergen is a particular substance that makes your body's immune system react abnormally, causing irritation and inflammation in the affected body part. See useful links for more information on allergic conjunctivitis.

Infective conjunctivitis

Infective conjunctivitis can be caused by a virus, bacteria or, in rare cases, by a sexually transmitted infection such as chlamydia or gonorrhoea. The most common symptoms include reddening and watering of the eyes. You may also notice a sticky coating on your eyelashes, particularly when you first wake in the morning, which can make your eyes feel like they're stuck together. Infective conjunctivitis is a very common condition and is responsible for 35% of all eye-related problems recorded in GP surgeries. It is most common in children and the elderly.

Infective conjunctivitis rarely requires any medical treatment because the infection will normally heal by itself, usually within one or two weeks. For most people, the condition does not cause any complications.

Those most at risk of developing complications from infective conjunctivitis are newborn babies, who are 28 days old or younger. An infection in the eye at a very young age can cause permanent damage. If you have infective conjunctivitis that is caused by a sexually transmitted infection (STI), your condition may last several months, rather than weeks.

Infective conjunctivitis occurs when the conjunctiva (the thin layer of cells covering the white of your eye and the inner surface of your eyelids) becomes inflamed as a result of an infection. There are a variety of factors which can cause an infection to develop in your eye. The three most common causes are:

  • bacteria,
  • viruses, and
  • sexually transmitted infection (STI).

There are no particular signs or symptoms that will allow your GP to distinguish between a bacterial infection and a viral infection. Both types of conjunctivitis will normally heal by themselves. If your conjunctivitis is caused by a sexually transmitted infection (STI), such as chalmydia, it will usually result in your conjunctivitis lasting for several months, rather than weeks.

If your condition is persistent, you will have an eye swab to determine the cause of the infection (see 'diagnosis' section). If your infective conjunctivitis is caused by an STI, you will have to undergo screening and treatment for the infection. Newborn babies can develop conjunctivitis if the mother has Chlamydia because the infection is often passed to the baby during birth.

Spreading the infection

You are more likely to develop infective conjunctivitis if you have been in close contact with someone who is already infected. It is therefore very important that you make sure that you wash your hands thoroughly after coming into contact with someone who has the condition.

In most cases of infective conjunctivitis, your GP will be able to diagnose the condition from your symptoms and by examination. Red, swollen eyes, which are covered in a sticky discharge, are very common features of infective conjunctivitis.

Other conditions

Most cases of infective conjunctivitis will heal without treatment within one to two weeks. If you are still suffering from the symptoms of conjunctivitis after two weeks, you will need to see your GP again, so that they can reassess your diagnosis and treatment.

Your GP will make sure that you are not suffering from a different form of the condition, such as allergic or irritant conjunctivitis, as this will affect the type of treatment you are prescribed. Your GP will also check to see that you are not suffering from any other eye condition, such as blepharitis which is a condition that causes your eyelids to become inflamed and swollen.

If you experience any of the following symptoms, you should see your GP immediately:

  • moderate to severe pain in your eyes,
  • photophobia (sensitivity to light),
  • disturbed vision, or
  • intense redness in your eyes.

It is very important for you to seek medical assistance if you experience these symptoms because it may be an indication that there is a more serious condition that is causing them. This is why it is important for your GP to rule out any other conditions which, if undiagnosed, may possibly cause serious complications.

Some conditions which may cause reddened eyes are outlined below.

  • Acute glaucoma – this is a rare form of glaucoma which causes a build up of pressure in the eye. Symptoms of pain, and loss of vision, can develop very rapidly. Left untreated, acute glaucoma can result in a permanent loss of vision.
  • Keratitis – this is when your cornea (the clear layer at the front of your eye that allows light to travel through your eye) becomes inflamed, and sometimes ulcerated. In severe cases, this can cause scarring of the cornea, which can lead to a permanent loss of vision.
  • Iritis – this condition causes your iris (the coloured part of your eye, behind the cornea) to become inflamed. If you have iritis, and it is not treated, it can cause the iris to stick to the front surface of the lens, which prevents fluid draining from the pupil. This can cause permanent damage to the eye.

Swab test

If your GP is unsure about the diagnosis, or needs to determine the cause of your infection, they may have to take a swab from your infected eye. This will be tested in a laboratory to find out the cause of your condition. Your GP can then provide you with the most appropriate treatment.

While your GP is awaiting the results of your swabs, you may be prescribed a short course of antibiotics to help keep your symptoms under control. When your GP finds out the results of the swab, you will then be prescribed the most suitable form of treatment for the cause of your condition.

Newborn babies

If your baby is 28 days old or younger and displays symptoms of infective conjunctivitis, it is important to contact your GP straight away. Many babies may have what is known as a 'sticky eye'. This usually occurs when the tear (lachrymal) duct cannot drain properly. If it cannot drain, it produces a discharge of pus, which can look similar to infective conjunctivitis. However, this condition is not serious, and does not require urgent treatment.

If your baby also has redness in their eye, it may be a sign that the eye is infected. Your GP will examine your baby closely to see if this is the case. Any newborn babies with infective conjunctivitis must be referred to an eye specialist (ophthalmologist) straight away, so that their condition can be managed and treated to prevent any damage occurring to the eye. Infective conjunctivitis in newborn babies (neonatal conjunctivitis) can, in rare cases, cause serious complications (see 'complications' section). However, with prompt treatment, most babies will make a full recovery.

The symptoms of infective conjunctivitis will normally begin in one eye. However, after a few days, you will often find that the other eye becomes affected too.

The symptoms of infective conjunctivitis can vary from person to person, but may include those listed below.

  • Reddening of the affected eye(s) – this happens as a result of the irritation and widening of the tiny blood vessels in your conjunctiva (thin layer of skin inside your eyelids). If your eyes are very red and very painful, or if your vision is affected, or if your eyes are extremely sensitive to light (photophobia), you should seek immediate medical assistance.
  • Watering eyes – the conjunctiva contain thousands of cells that produce mucus, and tiny glands that produce tears. Irritation causes the glands to become overactive, so that they water more than usual.
  • Sticky coating on eyelashes – you are more likely to notice this when you first wake in the morning. Your eyelids may feel like they are stuck together because the pus that is produced by the infection forms into sticky clumps on your lashes.
  • Slight soreness.
  • Swollen eyelids.
  • Enlarged lymph node in front of the ear – a lymph node is part of the body's immune system, and helps protect the body from bacteria and infection. You might feel an enlarged lymph node as a raised bump, underneath the skin.

If you are suffering from infective conjunctivitis, you may also have the symptoms of an upper respiratory tract infection. An upper respiratory tract infection is one that affects your throat and airways. Symptoms may include:

  • coughing,
  • fever,
  • headache, and
  • aching limbs.

The majority of cases of infective conjunctivitis do not require any medical treatment. As most infections will heal without treatment within one to two weeks, your GP may not initially prescribe any particular medicines or treatment for you.


If you have infective conjunctivitis, there are a number of ways that you can treat your condition at home. If you follow the guidelines which are outlined below, they should help to speed your recovery.

  • Remove contact lenses – if you wear contact lenses, you should take them out until all the signs and symptoms of the infection have been resolved. You should also avoid using contact lenses until 24 hours after you have finished a course of treatment, such as antibiotics.
  • Lubricant eye drops – these can be purchased over-the-counter (OTC), or they may be prescribed for you. They may help to ease any soreness and stickiness in your eyes.
  • Gently clean away sticky substances – when you wake in the morning, you may notice that your eyes have secreted a sticky substance that sticks to your eyelashes. You can gently clean this away from your eyelids and eyelashes using cotton wool soaked in water.
  • Wash your hands regularly – this is particularly important after you have touched your infected eye to prevent spreading infection to others.


In most cases, antibiotics will make little difference to your recovery from infective conjunctivitis. Therefore, you may be advised to delay using the medicine for seven days to see if the condition can resolve itself first.

About 10% of people who have their infective conjunctivitis treated with antibiotics experience adverse side effects. The risk of any complications from untreated infective conjunctivitis is very low, and so treatment with antibiotics is rarely necessary.

If your infective conjunctivitis is particularly severe, and has lasted for more than two weeks, you may require antibiotic treatment. Some schools, or playgroups, insist that a child is treated with antibiotics before they can return (although this is rarely necessary – see 'prevention' section). However, if this is the case, your GP may agree to prescribe antibiotics.

Which antibiotics may be prescribed?

If your GP decides that antibiotics are necessary for your treatment, there are two main types of antibiotics which may be prescribed. These are outlined below.

  • Chloramphenicol – this is the first choice of antibiotic to be used for severe infective conjunctivitis. It is usually in the form of an eye drop, which is taken every two hours, for two days, and then every four hours, for five days (but only while you are awake). If eye drops are not suitable, you may be prescribed this antibiotic in ointment form instead.
  • Fusidic acid – this is usually prescribed if chloramphenicol is not suitable for you. Fusidic acid is also more suitable for pregnant women. It comes in the form of eye drops, which normally have to be used twice a day, for seven days.

If you have been prescribed eye drops, your vision may become blurred shortly after using them. You should not to drive or operate machinery straight after using eye drops, and before doing so, you should always make sure that your vision is clear.

If you still have symptoms after two weeks, it is very important that you go back to your GP so that your condition can be reassessed, and your treatment reviewed.

You must also contact your GP immediately if you experience any of the following symptoms:

  • moderate to severe eye pain,
  • photophobia (sensitivity to light),
  • loss of vision, or
  • intense redness in your eyes.