NEW YORK (Reuters Health) – Four clinical factors can help rule out bacterial conjunctivitis in children, New York City researchers say.

The four factors are: age at least 6 years, only watery discharge (or no discharge), no glued eyes in the morning, and presentation between April and November, according to Dr. James A. Meltzer and colleagues from Jacobi Medical Center in the Bronx.

Children who met all four of these criteria had more than a 90% likelihood of a negative culture for bacterial conjunctivitis, the investigators report in the March issue of the Archives of Pediatrics and Adolescent Medicine.

The researchers say the goal of their study — which involved 368 patients ages 6 months to 17 years — was to determine whether a low risk of bacterial conjunctivitis could be predicted based on history and physical examination findings.

They note that up to 80% of the time, conjunctivitis in children is bacterial. But since there are no guidelines to help distinguish bacterial from nonbacterial cases, most clinicians prescribe antibiotics for all cases of acute conjunctivitis, even though “bacterial resistance to antibiotic drugs is an ever-increasing problem, and there is a nationwide effort to find conditions for which antibiotic drug use can be restricted.”

The children in the study had come to the authors’ pediatric emergency department with conjunctival erythema, eye discharge, or both. Any child with eye trauma, chemical exposure, contact lens use, or antibiotic use in the last 5 days was excluded. The study group was 52.7% male and the median age was 3 years.

For each child, the treating clinician completed a checklist of signs and symptoms and collected a conjunctival swab for bacterial culture.

Roughly 35% of subjects had negative conjunctival cultures. Using the researchers’ model, children with none of the specified characteristics had an 11.8% rate of negative cultures, compared to a 76.4% rate in children with three factors and a 92.3% likelihood of negative cultures for children whose eye conditions met all four criteria.

“If these findings are validated in other populations, we may be able to limit routine antibiotic drug administration for children with acute conjunctivitis,” the authors conclude.

Reference:

Arch Pediatr Adolesc Med 2010;164:263-267.