Head injury is one of the most common reasons for pediatric emergency visits, but most cases do not involve significant brain injury. CT scans are the most accurate way to detect intracranial bleeding or fractures, but they expose children to ionizing radiation, which increases lifetime cancer risk.

The PECARN rule, developed through the largest prospective pediatric head trauma study to date, offers evidence-based criteria to minimize unnecessary CT scans without missing clinically important brain injuries. The algorithm uses a small set of high- and intermediate-risk factors tailored to each age group.

For children under 2 years, risk factors include signs of skull fracture, non-frontal scalp hematomas, severe injury mechanisms and abnormal mental status. For children 2 years and older, risk factors include severe headache, vomiting, loss of consciousness and signs of skull fracture.

By following the PECARN rule, clinicians can improve diagnostic accuracy, protect children from unnecessary radiation exposure and make care more efficient in emergency settings.