Conjunctivitis

Conjunctivitis is inflammation of the transparent surface layer that covers the white of the eye (the conjunctiva).
 
About conjunctivitis
Types of conjunctivitis
Symptoms of conjunctivitis
Causes of conjunctivitis
Diagnosis of conjunctivitis
Treatment of conjunctivits
 
 

About conjunctivitis

There are two main types of conjunctivitis, based on what has caused the condition – an infection or an allergy.
 
Conjunctivitis can also be caused if an irritant such as a chemical, or a foreign body such as a piece of grit, gets into your eye.
 

Types of conjunctivitis

Infective conjunctivitis

Infective conjunctivitis is caused by infection of your eye with bacteria or a virus.
 
Sometimes babies develop conjunctivitis in the first few weeks after they are born. This can happen if an infection is passed from the mother's cervix (neck of her womb) or vagina during delivery, or if the baby has a reaction to a treatment applied to his or her eye. Contact your GP if your newborn baby has signs of an eye infection.
 

Allergic conjunctivitis

Allergic conjunctivitis can be caused by an allergy, such as an allergy to pollen (hay fever), house dust mites or cosmetics.
 
There are four types of allergic conjunctivitis:
 

• seasonal allergic conjunctivitis – this affects both of your eyes and people often get it at the same time as hay fever
• perennial allergic conjunctivitis – people with this type of allergic conjunctivitis have symptoms every day throughout the year in both eyes, often on waking each morning
• contact dermatoconjunctivitis – this type of conjunctivitis can irritate your eyelids and it occurs most often in people who use eye drops
• giant papillary conjunctivitis – this is common in people who use soft contact lenses, although it can also occur in people using hard contact lenses and after eye surgery

 
[Insert illustration with label: The different parts of the eye]
 

Symptoms of conjunctivitis
 

Conjunctivitis can affect one or both of your eyes and cause symptoms including:
 

• soreness, often described as a gritty or burning feeling
• redness of the whites of your eye
• blurred vision
• watering or discharge from your eye
• a slight sensitivity to light

 
Your symptoms will depend on which type of conjunctivitis you have.
 
If you have allergic conjunctivitis, you may also have:
 

• swollen eyelids
• itchy and watery eyes
• other hay fever symptoms, including sneezing, a runny, itchy nose and itchiness at the back of your throat
• a rash on your eyelids (if your conjunctivitis is caused by an allergic reaction to a medical or cosmetic product)

 
If you have infective conjunctivitis, you may also have:
 

• yellow pus-like discharge from your eyes, which might make your eyelids stick together after you sleep (if you have a bacterial infection)
• a watery discharge that can be crusty in the morning but isn’t pus-like (if you have a viral infection)
• cold-like symptoms, such as a fever and sore throat
• swollen lymph nodes in front of your ears (lymph nodes are glands throughout your body that are part of your immune system)

 
When to see a doctor

See your GP straight away if your eyes are very red, or if you have red eyes as well as:
 

• severe pain in your eyes
• sensitivity to light
• difficulty seeing

 
You should also contact your GP if you have had symptoms of conjunctivitis for more than a few days.
 

Causes of conjunctivitis

Infective conjunctivitis

Viruses are thought to be a more common cause of conjunctivitis than bacteria. The type of virus that usually causes the condition is called an adenovirus. This virus can also cause the common cold, so you may develop conjunctivitis at the same time as having a cold.
 
Common causes of bacterial conjunctivitis include the bacteria Staphylococcus aureus and Streptococcus pneumoniae. You can catch infective conjunctivitis from being in close contact with another person who has it. It’s important to wash your hands after coming into contact with someone who has the condition.
 
Infective conjunctivitis is most common in children and older people.
 

Allergic conjunctivitis

You might develop allergic conjunctivitis if you're allergic to plant pollens that are released into the air at around the same time each year. This is called seasonal allergic conjunctivitis or hay fever conjunctivitis.
 
Perennial (all year round) allergic conjunctivitis can be caused by house dust mites or animal fur.
 
Eye drops, cosmetics, and other chemicals can also cause allergic conjunctivitis – eye drops are the most common cause.
 
You can get a form of allergic conjunctivitis called giant papillary conjunctivitis if you use contact lenses, or after eye surgery.


 

Irritants

Foreign bodies, such as an eyelash or a piece of grit, or chemicals, such as chlorine, getting in your eye can cause conjunctivitis. Conjunctivitis caused by a foreign body may only affect one of your eyes.
 

Diagnosis of conjunctivitis

 
Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. You may be asked to read a chart to check your vision.
 
Your GP may use a special dye and a blue light to look at the surface of your eye. This is called a fluorescein examination. If your GP thinks that you have infective conjunctivitis, he or she may take a swab of your eye to identify the cause. The swab will be sent to a laboratory for testing.
 
Your GP may refer you to an ophthalmologist (a doctor who specialises in eye heath).
 

Treatment of conjunctivitis

Self-help

If you normally use contact lenses, don't wear them until the conjunctivitis has cleared up. It's also important that you don't rub your eyes because this can make inflammation worse.
 
If you have allergic conjunctivitis, try to keep away from whatever is causing the allergy. For example if you’re allergic to a cosmetic, don’t use it again and try an alternative product (wait until your symptoms have gone before you try the new product). It may be more difficult if you’re allergic to pollen, but keeping windows and doors closed on days when the pollen count is very high may help to reduce your symptoms. A cool compress (a facecloth soaked in cold water) may help to soothe your eyes.
 
Infective conjunctivitis usually settles without treatment within one to three weeks but this can vary between individuals. It may help if you clean your eyes and remove any secretions from your eyelids and lashes with cotton wool soaked in water.
 
Infective conjunctivitis is contagious. So it’s important to wash your hands regularly, particularly after touching your eyes. It’s best not to share pillows and towels. Don’t go swimming until your conjunctivitis has cleared up. You don't necessarily need to take time off work when you have conjunctivitis, and if your children develop it they can still go to school – unless there are many people affected in an ‘outbreak’ of conjuntivitis.
 

Medicines

If you have bacterial conjunctivitis, your GP may prescribe antibiotic eye drops or ointment. These are also available over-the-counter at a pharmacy.
 
Viral conjunctivitis will clear up on its own without the need for medicines.
 
If you have allergic conjunctivitis, antihistamine medicines may help. These are available over-the-counter from a pharmacy or your doctor can prescribe them. They are available in the form of eye drops or tablets.
 
Your doctor may also prescribe eye drops called mast cell stabilizers. These are also available over-the-counter. These are more effective at controlling your symptoms over a longer period of time (rather than antihistamines that will give rapid relief). It may take several weeks before you feel that they are having an effect, but you can take an antihistamine at the same time so that your symptoms can be controlled while you’re waiting.
 
Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist or doctor for advice.