Conjunctivitis: More Than Meets the Eye

Source: Frost HM, Jenkins TC, Meece JC, et al. Etiology and outcomes of acute infectious conjunctivitis in children. J Pediatr. 2025;276:114368; doi: 10.1016/j.jpeds.2024.114368.Investigators from multiple institutions conducted a case-control study to identify viral and bacterial pathogens associated with acute conjunctivitis in children. Secondary goals of the study were to compare the clinical presentation, response to ophthalmic antibiotics, and time to resolution among pediatric patients with conjunctivitis in whom a pathogen was, or wasn’t, identified. Cases were patients 6 months to 17 years old who presented with acute conjunctivitis to primary care clinics, urgent care centers, and pediatric emergency departments in Denver, CO, and Marshfield, WI, between 2019 and 2023. Controls were age-matched 1:1 to cases. Half the controls had symptoms consistent with an upper respiratory illness (URI), and half were “healthy” without signs of a URI. Conjunctival samples were obtained from cases and controls and PCR used to identify the presence of multiple viruses and bacteria. Multivariate regression was used to identify pathogens that were statistically associated with conjunctivitis, after controlling for multiple confounders. The medical records of patients with conjunctivitis were reviewed and information on physical examination findings and ophthalmic antibiotic ointment prescriptions abstracted. Parents of these children completed a survey 5 days after the index visit to indicate clinical improvement, resolution and adverse events related to antibiotic use. Regression analyses were used to compare these outcomes in patients with conjunctivitis in whom a pathogen was, or wasn’t, identified.Data were analyzed on 194 children with conjunctivitis and 196 controls. The median age of study patients was 5 years. Bacteria were identified in 76% of cases and 57% of controls, and viruses were identified in 5% and 11%, respectively. Among all pathogens, only H. influenzae was identified significantly more frequently in children with conjunctivitis than in controls (62% of cases vs 29% of controls; P <0.001). Among children with conjunctivitis, 77% of those with H. influenzae had purulent discharge compared to 53% of those with no specific pathogen identified (P = 0.012). Clear discharge, cough, and runny nose/congestion were associated with a significantly decreased rate of identification of H. influenzae in patients with conjunctivitis. Ophthalmic antibiotics were prescribed for 105 (54%) children with conjunctivitis. By day 5, conjunctivitis was improved in 96% of patients and resolved in 85%. Neither clinical improvement nor resolution were associated with a prescription for ophthalmic antibiotics, both among all patients with conjunctivitis and in those in whom H. influenzae was the pathogen. Among children prescribed an ophthalmic antibiotic, 21 (20%) had an adverse event reported by their parent.The authors conclude that H. influenzae was the only pathogen tested that was associated with acute conjunctivitis in children.Dr Dubik has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Most cases of conjunctivitis are self-limited, resolving in 7–10 days without treatment with antibiotics,1 yet antibiotics usually are prescribed.2 (See AAP Grand Rounds. 2023;49[1]:4.)3Transmission may occur via contaminated fingers, from the nasopharynx, or fomites (eg, contact lenses).4 In the current study, bacteria were detected in the conjunctiva of most children, ill or healthy. However, only H. influenzae was significantly associated with conjunctivitis. Clinical resolution occurred in 85% of children by day 5, regardless of whether they were prescribed an antibiotic.The current authors opted “to test for organisms historically associated with conjunctivitis,” and it is not clear whether their PCR panel included C. trachomatis or N. gonorrheae, organisms that should be considered if sexual abuse is suspected.5 If the patient wears contact lenses, P. aeruginosa must also be considered.4Many factors ought to be considered when deciding whether to prescribe an antibiotic for conjunctivitis, including parent expectations, clinical presentation, school/day care policies, and lost parenteral work hours. Pediatric guidelines state that antibiotic treatment is not required to return to school or day care.6 However, school and day care policies vary widely.7 These may require a health care assessment, treatment with an antibiotic, or absence from school until all signs and symptoms have resolved.8A recent article explored the clinical decision-making for pediatric conjunctivitis. They argued for clear guidelines for evaluating and managing infectious conjunctivitis and updated school/daycare exclusion guidelines.9The authors of the current study conclude that because this is a self-limiting condition and the efficacy of antibiotics is debatable, clinicians ought to judiciously weigh the risks and benefits before prescribing.Think twice before prescribing antibiotics for conjunctivitis.Less is often more in pediatrics. The results of this study suggest that we should prescribe ophthalmic antibiotics less, and exclude from day care/school less, in children with uncomplicated conjunctivitis.