Conjunctivitis refers to inflammation of the white part of the eye (the conjunctiva). It typically presents as a red swollen eye that may be tearing excessively and or have a sticky mucous discharge. The eye may feel tender, burning, itchy or actually painful. The eyelids may stick together after sleep.

The most common causes of conjunctivitis are infection and allergy:

  • Infection – viral or bacterial conjunctivitis is spread from person to person (hand to face contact mainly). It often involves a sticky discharge and some pain, although itch is less often noted. These infections usually clear on their own but antibiotic eye drops are commonly used to shorten the illness in bacterial or suspected-bacterial conjunctivitis.
  • Allergy – allergic conjunctivitis may be a once-off short term allergy or a more chronic ongoing one, or a combination of both. It involves less discharge and more itch than infections do. Treatment involves avoiding triggers (e.g. cut grass, animals, pollen) and or the use of antihistamines (eye drops or tablet form) and more specialised eye treatments for allergy.

There are certain less-common special types of conjunctivitis that require different approaches. These include conjunctivitis in newborn babies (may involve a maternal infection being passed on), patients who wear contact lenses (more thorough treatment and eye hygiene  is essential), and cases where infection with an STI is suspected (various STIs like gonorrhoea and herpes can cause conjunctivitis).

Anyone who develops a painful or red eye suddenly should seek medical care promptly because even though conjunctivitis is generally a mild self-limiting illness, there are other more-serious causes for red eyes and painful eyes (e.g. Glaucoma, Herpes infection, corneal ulceration, etc.).

Conjunctivitis is a condition we have probably all had, or will have. It is generally a mild and self-limiting condition although other potentially more serious diagnoses are possible and should always be considered.