Conjunctivitis is redness and inflammation of the thin layer of tissue that covers the front of the eye (conjunctiva). It is very common.
People often refer to conjunctivitis as red eye.
Other symptoms of conjunctivitis include itchiness and watering of the eyes, and sometimes a sticky coating on the eyelashes (if it's caused by an allergy). Read more about the symptoms of conjunctivitis.
Conjunctivitis can affect one or both eyes.
What causes conjunctivitis?
The conjunctiva can become inflamed as as result of:
Read more about the causes of conjunctivitis.
Conjunctivitis often doesn't require treatment as the symptoms usually clear up within a couple of weeks. If treatment is thought necessary, the type of treatment will depend on the cause but in most cases antibiotic eye drops can be used to clear the infection.
Irritant conjunctivitis will clear up as soon as whatever is causing it is removed.
Allergic conjunctivitis can usually be treated with anti-allergy medications such as antihistamines. If possible, avoid the substance that triggered the allergy.
It's best not to wear contact lenses until the symptoms have cleared up. Any sticky or crusty coating on the eylids or lashes can be cleansed with cotton wool and water.
Infective conjunctivitis is easily spread, although it isn't necessary to stay away from work or keep your child away from school. Washing your hands regularly and avoiding sharing pillows or towels will help prevent it spreading.
Read more about treating conjunctivitis.
See your GP immediately if you have:
Conjunctivitis can be a frustrating condition - especially allergic conjunctivitis - but in most cases it doesn't pose a serious threat to health.
Complications of conjunctivitis are very rare but when they do occur they can be serious, such as:
Read more about the complications of conjunctivitis.
Symptoms of conjunctivitis
The symptoms of conjunctivitis will depend of the cause, but the general symptoms include:
If you have infective conjunctivitis you may also have:
You may also have itchy eyes if you have allergic conjunctivitis.
The pattern of symptoms for allergic conjunctivitis depends on the substance you are allergic to.
Allergies to pollen (hay fever) occur during certain parts of the year. You can have an allergy to:
It is highly likely that the pollen will also cause other symptoms such as sneezing and a runny or blocked nose.
Allergies to dust mites or animal fur cause symptoms throughout the year. Both eyes are usually affected and you may find the symptoms worse in the morning.
Some people develop an allergy to eye drops. This is known as contact dermatoconjunctivitis and can also affect your eyelids, causing them to become dry and sore.
Some people are allergic to wearing contact lenses, which is known as giant papillary conjunctivitis. The symptoms progress much more slowly and you may also develop small spots on the inside of your upper eyelids. This type of conjunctivitis carries a high risk of complications so you need to get medical advice.
When to seek medical advice
Most case of conjunctivitis are not a cause for concern but contact your GP if you think you have it - especially if you think the conjunctivitis is related to wearing contact lenses.
Your GP will be able to check whether there is a more serious underlying cause of your symptoms.
When to seek immediate medical advice
The following symptoms could be the sign of a more serious eye condition:
If you experience any of these symptoms, contact your GP immediately. If this isn't possible, visit your nearest accident and emergency (A&E) department.
Causes of conjunctivitis
Conjunctivitis is a condition that occurs when the conjunctiva (a thin layer of cells covering the front of your eyes) becomes inflamed.
The three most common causes of this inflammation are:
These are discussed in more detail below.
Eye infections are most commonly caused by:
There are no particular signs or symptoms that will allow your GP to distinguish between a bacterial or viral cause of infective conjunctivitis. If your condition is does not heal quickly, an eye swab will determine the cause of the infection (read more about diagnosing conjunctivitis).
Spreading the infection
You are more likely to develop infective conjunctivitis if you have been in close contact with someone who is already infected with it.
It is therefore very important to wash your hands thoroughly after coming into contact with anyone who has infective conjunctivitis. Don't share pillows or towels with anyone with the infection.
You may be more at risk of infective conjunctivitis if:
Allergic conjunctivitis is caused when your eyes come into contact with an allergen. An allergen is a particular substance that causes your immune system to react abnormally. This is known as an allergic reaction.
There are four main types of allergic conjunctivitis:
Seasonal and perennial conjunctivitis
Seasonal and perennial allergic conjunctivitis are usually caused by:
These types of conjunctivitis are more common among people who also have other allergies, such as asthma, and often occur with allergic rhinitis (an allergy that affects the nose, causing sneezing and a blocked or runny nose).
Contact dermatoconjunctivitis is usually caused by eye drops, but it can also be caused by make-up or chemicals.
Giant papillary conjunctivitis
Giant papillary conjunctivitis is caused by:
Giant papillary conjunctivitis is estimated to affect around 1%-5% of people who use soft contact lenses and 1% of people who use hard contact lenses.
Irritant conjunctivitis can have a wide range of potential causes. Some common causes include:
Your GP should be able to diagnose conjunctivitis by asking about your symptoms and examining your eyes.
It can be helpful to describe to your GP how your conjunctivis started as this will help them diagnose which type it is and whether it needs to be treated.
The most common symptoms of infective conjunctivitis are sticky, red and watery eyes. However, infective conjunctivitis can sometimes be confused with other types of conjunctivitis, which are treated differently.
Your GP may suggest further tests (such as a swab test) if your conjunctivitis hasn't responded to treatment or to help decide what treatment to use.
A swab looks similar to a small cotton bud. It's used to collect a small sample of mucus from your infected eye, which is sent to a laboratory to find out the cause of your conjunctivitis.
Find out more about treatments for infective conjunctivitis.
If your symptoms are severe or do not respond to treatment, you may need to see an eye specialist (ophthalmologist).
Most cases of conjunctivitis clear within one to two weeks, sometimes sooner, without needing any medical treatment.
If you have any unusual symptoms such as severe pain, blurred vision or sensitivity to light, these may mean that you have a more serious condition.
If you have any of these symptoms, it is very important to seek medical assistance immediately, either by contacting your GP or visiting a hospital.
Other more serious conditions include:
Contact your GP straight away if you think your baby may have infective conjunctivitis (also called neonatal conjunctivitis).
If this is not possible, call NHS Direct on 0845 46 47 or your local out-of-hours service. Your GP will examine your baby closely to see if they have sticky eyes or infective conjunctivitis.
Any newborn baby with infective conjunctivitis must be referred to an eye specialist straight away for treatment.
Find out more about the symptoms of infective conjunctivitis.
The recommended treatment for conjunctivitis will depend on whether it is caused by infection, an allergic reaction or an irritant such as a stray eyelash.
Each treatment option is discussed in more detail below.
Most cases of infective conjunctivitis do not require medical treatment and will clear up in one to two weeks.
There are several ways that you can treat infective conjunctivitis at home. The following advice should help ease your symptoms:
Antibiotics are not usually prescribed for infective conjunctivitis because they make little difference to your recovery and there is a very low risk of complications for untreated conjunctivitis.
However, if the infection is particularly severe or it has lasted for more than two weeks, you may be prescribed antibiotics. Some schools or playgroups may insist that a child is treated with antibiotics before they can return, although this is rarely necessary (see preventing infective conjunctivitis).
The two main types of antibiotics that may be prescribed are:
Chloramphenicol is usually the first choice and comes in the form of eye drops. They are used as follows:
You only need to use the drops while you are awake. If your symptoms improve within the first five days, continue to use the eye drops for another two days.
If eye drops are not suitable for you, you may be prescribed the antibiotic as an eye ointment instead.
Fusidic acid may be prescribed if chloramphenicol is not suitable for you. It's often better for children and elderly people as it doesn't need to be used as often. It is also the preferred treatment for pregnant women.
Fusidic acid comes in the form of eye drops, which are normally used twice a day for seven days.
Eye drops can briefly cause blurred vision. Avoid driving or operating machinery straight after using eye drops.
Usually, neither chloramphenicol nor fusidic acid cause side effects, although they can cause a slight stinging or burning sensation in your eye. This feeling should not last long.
If you still have symptoms after two weeks, it is very important to go back to your GP. Also contact your GP immediately if you experience any of the following symptoms:
Your GP may suggest that you are tested for sexually transmitted infections (STIs). Some STIs, such as chlamydia, can cause infective conjunctivitis. In this case, your symptoms may last for several months.
Your treatment will depend on which type of allergic conjunctivitis you have.
The four main types of allergic conjunctivitis are:
Whatever the cause, you will find that some self-help methods can ease your symptoms.
If you have allergic conjunctivitis, you can follow the guidelines below to treat your condition at home:
See preventing allergic conjunctivitis for more advice.
Seasonal and perennial allergic conjunctivitis
If you have seasonal or perennial conjunctivitis you may be prescribed the following medicines:
These are described in more detail below.
If your allergic conjunctivitis requires rapid relief, your GP will probably prescribe a medicine known as an antihistamine.
Antihistamines work by blocking the action of the chemical histamine, which the body releases when it thinks it is under attack from an allergen. This prevents the symptoms of the allergic reaction from occurring.
Antihistamine eye drops
You may be prescribed antihistamine eye drops, such as:
Antazoline with xylometazoline (Otrivine-Antistin) is also available over the counter from pharmacies without prescription. Always follow the manufacturer's instructions.
If you are pregnant or breastfeeding, some antihistamine eye drops may not be suitable. Speak to your GP for advice.
You may be prescribed an antihistamine such as:
You will usually only have to take an antihistamine once a day.
If possible, oral antihistamines should not be taken if you are pregnant or breastfeeding. Speak to your GP for advice.
Although new antihistamines should not make you drowsy, they may still have a sedating effect. This is more likely if you take high doses or drink alcohol while you are taking antihistamines.
Mast cell stabilisers
Mast cell stabilisers are an alternative type of medicine. Unlike antihistamines, they will not provide rapid relief from your symptoms, but they are more effective at controlling your symptoms over a longer period of time.
It may take several weeks to feel the effects so you may also be prescribed an antihistamine to take at the same time.
Mast cell stabilisers that are commonly prescribed in the form of eye drops include:
If your symptoms of allergic conjunctivitis are particularly severe, you may be prescribed a short course of oral corticosteroids (steroids tablets, capsules or a liquid you can drink). However, these are not usually prescribed unless absolutely necessary.
Read more about corticosteroids.
Giant papillary conjunctivitis
As giant papillary conjunctivitis is usually caused by contact lenses, the symptoms often clear up after you stop wearing them. The spots that form on the inside of your upper eyelid may last slightly longer.
If you develop giant papillary conjunctivitis as a result of recent eye surgery, you will be immediately referred to an ophthalmologist. This is to ensure that your eyes can be carefully monitored and the most effective treatment given.
Most cases of irritant conjunctivitis do not require any treatment as the condition should clear up once the irritant is removed from the eye.
An exception to this is if your eyes were exposed to harmful substances such as bleach or acid. This is usually regarded as medical emergency and you will need to be admitted to hospital so your eyes can be washed out with saline solution.
Complications of conjunctivitis
Complications with conjunctivitis depend on whether the condition is an infection (infective conjunctivitis) or an allergic reaction (allergic conjunctivitis).
Infective conjunctivitis caused by any type of bacteria can cause a number of complications, particularly in babies born prematurely (before week 37 of pregnancy).
Possible complications include:
In newborn babies (neonates) who are up to 28 days old, infective conjunctivitis can lead to a severe and rapidly progressive eye infection. If this is not treated, it can result in permanent damage to your child's vision.
If your newborn baby is found to have infective conjunctivitis, they will be referred immediately for specialist assessment and treatment. Their condition will be closely monitored. Complications are rare and most babies make a full recovery from infective conjunctivitis.
After having infective conjunctivitis caused by chlamydia, around one-in-five babies may develop pneumonia (a type of lung infection). This is a potentially life-threatening condition in young babies and may require treatment in hospital.
If your conjunctivitis is due to an allergic reaction to pollen, dust mites or similar (seasonal and perennial allergic conjunctivitis), it is very rare to experience any serious complications.
However, you may find your reoccurring symptoms frustrating. For example, if your conjunctivitis is caused by pollen, you may find it difficult to go outside during the spring and summer months without triggering your symptoms.
This type of allergic conjunctivitis can affect your daily life and could make it difficult for you to concentrate at work or school, particularly if your eyes are severely irritated. Although this can affect your quality of life, it should not cause any long-term health problems. Read more about living with an allergy.
Punctate epithelial keratitis
Some types of conjunctivitis can cause a condition called keratitis. Keratitis is where your cornea (the front of your eye) becomes inflamed (swollen).
This can be painful and make your eyes sensitive to light (photophobia). Sometimes, ulcers (open sores) form on the cornea. If the ulcers scar your cornea, your vision may be permanently damaged.
Contact your GP immediately if you experience any unusual symptoms (read more about the symptoms of conjunctivitis) or visit your nearest accident and emergency (A&E) department.
Eye expert Professor Harminder Dua on the questions to ask
Infective conjunctivitis is an infection of the delicate membrane that covers the eyeball and stretches to the inside of the eyelids. Infective conjunctivitis can cause sticky, red and watery eyes. Most cases soon clear.
Professor Harminder Dua, consultant in ophthalmology at University Hospital, Nottingham, tells us what he would want to know about infective conjunctivitis.
What's the difference between infective and allergic conjunctivitis?
Infective conjunctivitis is caused by viruses or bacteria. Infective conjunctivitis is often spread from one person to another by direct contact, such as with fingers, tissues or towels contaminated with discharge from the eyes. A sticky discharge, which may be white, yellow or greenish in colour, is often a symptom of infective conjunctivitis. Eyes with infective conjunctivitis tend not to itch as much as those with allergic conjunctivitis, but the symptoms are similar.
Allergic conjunctivitis is caused when the immune system has an abnormal response to common allergens such as pollens, dust and animal hair. Itching is the main symptom of allergic conjunctivitis, together with burning and smarting (blinking) of the eyes. Watering eyes and sensitivity to light are also common features. The discharge is clear and watery or mucoid (stringy).
Will conjunctivitis affect my vision?
Conjunctivitis generally doesn't affect eyesight, and most people make a complete recovery. You may experience temporary obscured or blurred vision in some instances, but this will pass.
Infective conjunctivitis can spread to the cornea (the clear window of the eye) and sight can be affected, although this isn't common.
Are there any long-term effects?
Most cases of conjunctivitis recover completely without any long-term effects.
My child has infective conjunctivitis. Should I keep them off school?
If your child has infective conjunctivitis and they feel unwell, they should stay away from school.
Any sign of conjunctivitis in a newborn child should be taken very seriously, and you should seek medical attention immediately.
I have conjunctivitis in one eye. Will I get it in the other eye?
Conjunctivitis usually affects both eyes, although one eye may be worse than the other. Occasionally, infective conjunctivitis can affect only one eye. In this case, take extreme care to avoid touching the eye area because fingers, towels or tissues can spread the infection to the other eye.
Is there anything I can do to relieve the itching?
A cold compress applied to the closed eyelids can provide relief from itching and sore eyes.
Avoid rubbing your eyes no matter how strong the urge, because this can damage the clear surface of the eye.
Can it be treated?
Infective conjunctivitis usually goes away on its own and doesn't need antibiotic treatment. However, antibiotic drops are often prescribed by GPs to prevent any secondary bacterial infection.
Infective conjunctivitis with discharge, especially in children, is more likely to require antibiotic eye drops or ointment.
It's difficult for me to open my eyes in the morning. How can I ease this?
A common cause for the eyelids being stuck together in the morning is the large amount of discharge that dries on the lids during the night. You can gently wipe it away with a ball of cotton wool soaked in warm water.
Can I wear contact lenses if I have conjunctivitis?
Contact lenses of any type should be avoided until your conjunctivitis has completely settled.
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