What Are the Main Causes of Conjunctivitis?
Conjunctivitis can be caused by a virus, bacteria or by allergies. Bacterial and viral conjunctivitis are easily spread from person to person. Allergic conjunctivitis is not contagious.
Viral conjunctivitis is the most common type of conjunctivitis. This type of pink eye is very contagious and often spreads through schools and other crowded places. It usually causes burning, red eyes with a watery discharge. Viral conjunctivitis is usually caused by the same virus that causes runny nose and sore throat in people with the common cold.
Bacterial conjunctivitis is also very contagious. An infection from bacteria causes this form of pink eye. With bacterial conjunctivitis, you have sore, red eyes with a lot of sticky pus in the eye. Some bacterial infections, however, may cause little or no discharge. Sometimes the bacteria that cause pink eye are the same that cause strep throat.
Allergic conjunctivitis is a type of pink eye that comes from an allergic reaction to pollen, animals, cigarette smoke, pool chlorine, car fumes or something else in the environment. It is not contagious. Allergic pink eye makes your eyes very itchy, red and watery, and the eyelids may get puffy.
Treatment isn’t usually needed for conjunctivitis, because the symptoms often clear up within a couple of weeks. If treatment is needed, the type of treatment will depend on the cause. In severe 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, you should 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 eyelids or lashes can be cleansed with cotton wool and water.
Washing your hands regularly and not sharing pillows or towels will help prevent it spreading.
See your GP immediately if you have:
- eye pain
- sensitivity to light (photophobia)
- disturbed vision
- intense redness in one eye or both eyes
- a newborn baby with conjunctivitis
Work and school
It is advised that you don’t need to stay away from work or school if you or your child has conjunctivitis, unless you (or they) are feeling particularly unwell.
If there are a number of conjunctivitis cases at your child’s school or nursery, you may be advised to keep them away until their infection has cleared up.
Generally, adults who work in close contact with others, or share equipment such as phones and computers, shouldn’t return to work until the discharge has cleared up.
Conjunctivitis can be a frustrating condition – particularly allergic conjunctivitis – but in most cases it doesn’t pose a serious threat to health.
Complications of conjunctivitis are rare, but when they do occur they can be serious and include:
- a severe case of allergic conjunctivitis can lead to scarring in the eye
- in cases of infective conjunctivitis, the infection can spread to other areas of the body, triggering more serious secondary infections, such as meningitis