Identifying children at low risk for bacterial conjunctivitis.

OBJECTIVE To identify a population of children at low risk for bacterial conjunctivitis on the basis of history and physical examination findings. DESIGN Prospective observational cohort study. SETTING Urban pediatric emergency department. PARTICIPANTS Children aged 6 months to 17 years with conjunctival erythema, eye discharge, or both. The exclusion criteria were eye trauma, exposure to a noxious chemical, contact lens use, and antibiotic drug use in the past 5 days. INTERVENTIONS Clinicians completed a checklist of signs and symptoms and collected a conjunctival swab for bacterial culture. MAIN OUTCOME MEASURES The chi(2) test, the Mann-Whitney test, and logistic regression were used to create a prediction model for a negative bacterial culture. RESULTS Of 368 patients enrolled, 194 (52.7%) were males. The median patient age was 3 years (interquartile range, 1-5 years). Conjunctival cultures were negative in 130 patients (35.3%). Age 6 years or older, presentation in April through November, no or watery discharge, and no glued eye in the morning were the clinical factors found to be independently associated with a negative conjunctival culture. If 3 factors were present, 76.4% (95% confidence interval, 63.6%-85.6%) of patients had a negative culture. If all 4 factors were present, 92.3% (95% confidence interval, 66.1%-98.2%) of patients had a negative culture. CONCLUSION The combination of 4 clinical factors may enable clinicians to identify children at low risk for bacterial conjunctivitis and may reduce routine antibiotic drug administration.