Is this red eye a bacterial conjunctivitis? – a user’s guide to correct treatment

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Goodfellow Gems

"Is this red eye a bacterial conjunctivitis? – a user’s guide to correct treatment"

There are some features that distinguish a bacterial from a viral/allergic conjunctivitis. As the authors point out most bacterial conjunctivitis spontaneously resolves within seven days without antibiotics so we are often shortening the duration of symptoms by 0.5 to 1.5 days.1 The NNT to get 1 extra patient into remission in the first two to five days is 6. Preauricular adenopathy was not helpful contrary to traditional belief. The “pink eye” of day care concern is usually a viral/allergic conjunctivitis and the information below may help with a rational approach to treatment.

Tend to rule in a bacterial eye infection.

  1. Both eyes stuck down in the morning.
  2. Redness that obscures the tarsal vessels.
  3. Occurs during winter/spring.
  4. Observed purulent discharge.

Tend to rule out a bacterial eye infection

  1. Cannot observe a red eye at 20 feet.
  2. Absence of morning gluing of either eye.
  3. History of conjunctivitis.



  1. Narayana S et al. Bedside Diagnosis of the 'Red Eye': A Systematic Review. Am J Med. 2015 Nov;128(11):1220-1224.e1. doi: 10.1016/j.amjmed.2015.06.026.

Gems are chosen by the Goodfellow director Dr. Bruce Arroll to be either practice changing or practice maintaining. The information is educational and not clinical advice.

As published in NZ Doctor 11/05/2016