Conjunctivitis, an inflammation of the conjunctiva of one or both eyes, characterised by redness, itching, and discharge. Several different forms of this disorder exist and, in infective cases, it may be caused by either bacteria or viruses. Similar symptoms can also occur during an allergic reaction (for example, in hay fever).
Bacterial conjunctivitis may be caused by Haemophilus aegypticus, which is common in warmer weather. Epidemics have been reported and treatment is normally with antibiotic eye drops. Bacterial conjunctivitis may also be caused by chlamydia. Viral conjunctivitis may be caused by adenoviruses and in children this is sometimes associated with pharyngitis (throat infection) and fever. In adults, the conjunctivitis is normally the only symptom. Another type of adenovirus is responsible for keratinoconjunctivitis, which occurs in people who come into contact with dust or other small particles that cause corneal irritation (for example, welders). It is sometimes known as "shipyard eye". This type of conjunctivitis may cause the cornea to become opaque and lead to impaired vision.
A condition known as acute hemorrhagic conjunctivitis is caused by an enterovirus. Also known as Picornavirus epidemic conjunctivitis, this type of conjunctivitis was first recognised in 1969 when it appeared as a pandemic in Africa and South-East Asia. It is highly infectious and passes between members of families; it can also be spread at eye clinics. The redness and inflammation of the eye is also associated with bleeding (acute subconjunctival haemorrhage). This makes the disease more serious than other types of conjunctivitis as it can cause blindness in its severest form; however, complete recovery normally occurs within one or two weeks.
Conjunctivitis is also seen as a complication of other systemic disorders, for example, in ulcerative colitis (a disease of the gut) or in Reiter's disease accompanied by arthritis.