Conjunctivitis

Conjunctivitis causes

Conjunctivitis is caused by infection or irritants, including allergens.

The most common infective reason for a mild conjunctivitis, lasting just a few days, is the simple inflammation of the conjunctiva that occurs with a viral illness such as colds or flu. This type of viral conjunctivitis is rarely serious, causing temporary redness, watering and discomfort. There is no specific treatment for this form, other than cleansing with cooled, boiled water.

Other viral infections, such as the herpes virus, can be more serious and may cause a more prolonged inflammation that can be hard to treat, resulting in ulcers and damage to the corneal surface of the eye.

If symptoms last more than four days, are not associated with a cold or are severe you should get your eyes checked.

In newborn babies, there is a higher risk of bacterial infection contracted from the normal bacteria that exist in the mother's birth canal, or more seriously, from the mother carrying untreated sexually transmitted pathogens such as chlamydia, gonorrhoea or herpes.

Bacterial infections can occur in all ages, are more likely to cause sticky discharge and crusting then viral infections. They may need antibiotic cream if it doesn't clear after a few days.

Conjunctivitis symptoms

Conjunctivitis causes redness of the conjunctiva (the white of the eye and inside the eyelids), usually of both eyes. The eyes may be sore, itchy, burning and sometimes extremely painful. Bright light can make the condition seem worse.

If the cause is a bacterial infection, the eye may discharge a white/yellow sticky pus. This can crust on the eyelashes and glue the eyelids together, especially after sleep.

If an allergen is causing the conjunctivitis, the eyes may be swollen, itchy and produce a thin, watery discharge.

Conjunctivitis treatments

If you suspect conjunctivitis, your doctor will be able to confirm it.

With newborn babies, simply cleaning the eyes may be all that's needed to help the condition settle.

Viral conjunctivitis usually lasts a matter of days, and complications are extremely rare.

For most people, the infection clears up within a week without needing specific treatment. Antibiotics make very little difference, so nowadays they're less often recommended. Occasionally a more severe conjunctivitis can develop which involves the cornea (the area of the surface membrane that covers the iris and pupil). This type of conjunctivitis, for example caused by an infection with the Herpes virus in adults, may last several weeks and may require more intensive treatment with antibiotics and steroids, and careful follow-up by a specialist.

Allergic conjunctivitis is treated with anti-inflammatory eye drops. Gently bathing the eye and lashes with cooled boiled water may help.

So to sum up, most simple viral and bacterial infections in a healthy person with a good immune system will settle without treatment, but look out for prolonged or severe symptoms. See your GP if you are at all worried.