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Should all patients with acute conjunctivitis be treated with antibiotics?

Three Part Question

In [patients with acute conjunctivitis], does [treatment with antibiotics] have any [effect on clinical improvement]?

Clinical Scenario

A healthy 25 year-old male presents to the emergency department with acute conjunctivitis. You suspect that it is likely viral in etiology, but you cannot rule out a bacterial source. You wonder if he should be started on antibiotics.

Search Strategy

Medline 1950-04/08 using the OVID interface, Cochrane Library (2008), PubMed
clinical queries [(exp conjunctivitis) AND (Anti-Bacterial Agents/tu )]. LIMIT to human AND English

Search Outcome

158 papers found of which only six randomised controlled trials were found in which any form of antibiotic treatment had been compared with placebo in the management of acute bacterial conjunctivitis. This included topical, systemic and combination (for example, antibiotics and steroids) antibiotic treatments. A Cochrane Systematic Review (updated in 2006) included five of these controlled trials.


Few studies exist in which patients with acute conjunctivits are randomized to topical antibiotics versus placebo. While the majority of cases are likely caused by viruses, some cases are bacterial, though still considered self-limiting. Antibiotics are often prescribed to supposedly speed recovery and prevent complications; however, the actual incidence of complications in either treatment group is questionable. The cost effectiveness of antibiotic treatment still needs to be studied. The above studies found that clinical improvement was hastened in the treatment groups early, yet by day 6 the difference was minimal.

Clinical Bottom Line

Treatment of acute conjunctivitis with antibiotics may result in early improvement of symptoms, yet the full course of illness is less likely to be hastened. In addition, one must weigh the risks and benefits of treatment against the fact that this is generally a self-limited illness.