For healthcare professionals

PECARN Head Injury Rule

The PECARN rules help decide which children with a minor head injury need a CT scan of the head. There are two versions: one for children under 2 years and one for children 2 years and older. Kuppermann and colleagues published them in 2009. This tool is written for clinicians and is not a diagnosis.

Last reviewed: 2026-11-02 By the uncovermyrisk.com editorial team Educational only, not medical advice.

A child with a head injury who has a seizure, will not wake up normally, keeps vomiting or is getting more drowsy or confused: call 911 now.General safety advice (not part of the published rules). The rules are for children already being assessed; they do not replace urgent care.

Source

Kuppermann N and colleagues, The Lancet 2009. The predictors for each age group are taken from the open-access (CC BY) table by Wickbom and colleagues, EClinicalMedicine 2025, and the three recommendation levels from Alsuwais and colleagues, European Journal of Pediatrics 2025 (CC BY). Definitions follow Sawaya and colleagues, BMC Pediatrics 2020 (CC BY). The tests check every predictor in both age groups, that each group ignores the other group's predictors, and the order of high over intermediate risk.

Validated in

Children with minor blunt head trauma. Cho and colleagues validated the rules in 448 children in Korea, excluding those with a Glasgow Coma Scale score under 14, neurological disease or a trivial mechanism such as a ground-level fall. Wickbom and colleagues compared them with other rules in 3012 children in Sweden and Norway.

Limits

In the Korean study the rules had a sensitivity of 100% in both age groups, with a specificity of 81.1% under 2 years and 74.6% at 2 years and older (Cho 2022). In the Scandinavian study, sensitivity for significant CT findings was 74.1% for the rules for 2 years and older (Wickbom 2025). In the intermediate group, the rules leave the choice to clinical judgement.

Children under 2 years

The predictors for children under 2 years are (Wickbom 2025):

High risk (CT recommended): Glasgow Coma Scale score of 14 (under 15), other signs of altered mental status, or a palpable or unclear skull fracture
Intermediate risk (CT or observation): occipital, parietal or temporal scalp hematoma; loss of consciousness for 5 seconds or more; severe mechanism of injury; not acting normally per parent

Children 2 years and older

The predictors for children 2 years and older are (Wickbom 2025):

High risk (CT recommended): Glasgow Coma Scale score of 14 (under 15), other signs of altered mental status, or signs of basilar skull fracture
Intermediate risk (CT or observation): any loss of consciousness, vomiting, severe mechanism of injury, or severe headache

With none of the high-risk findings, CT or a period of observation is recommended if any intermediate finding is present; with no finding at all, a head CT is not recommended (Alsuwais 2025).

Definitions

Severe mechanism: motor vehicle crash with ejection, death of another passenger or rollover; pedestrian or bicyclist without a helmet struck by a motorized vehicle; a fall of more than 0.9 m (under 2 years) or more than 1.5 m (2 years and older); or the head struck by a high-impact object (Sawaya 2020)
Altered mental status: agitation, somnolence, repetitive questioning or slow response to verbal communication (Sawaya 2020)
Signs of basilar skull fracture: Battle's sign, raccoon eyes, hemotympanum, cerebrospinal fluid otorrhea or rhinorrhea (Sawaya 2020)

The rules were derived and validated by Kuppermann and colleagues (Kuppermann 2009).

Worked example: a 3-year-old who fell 1 m from a sofa, vomited once and is now alert with a Glasgow Coma Scale score of 15 has one intermediate finding (vomiting), so the rules leave the choice between a head CT and a period of observation.

What the studies found

In 448 children in two Korean pediatric emergency departments, no clinically important traumatic brain injury was found in the very low risk group, the rules had a sensitivity of 100% in both age groups, and CT was used in 14.7% of children compared with 33.8% in the original PECARN study (Cho 2022).

In 3012 children in 16 emergency departments in Sweden and Norway, sensitivity for significant CT findings ranged from 74.1% (PECARN and PREDICT for 2 years and older) to 100% (the Scandinavian guideline) across the rules compared (Wickbom 2025).

Related calculators

For adults with minor head injury, see the Canadian CT Head Rule. To score the level of consciousness, use the Glasgow Coma Scale calculator. Other bedside scores are listed under For healthcare professionals.

For a febrile infant 60 days old or younger, see the Rochester criteria.

Sources

Wickbom F, Thornberg S, Sotoca Fernandez J, et al. Comparison of predictive tools for management of paediatric mild TBI: a prospective cohort study. EClinicalMedicine. 2025;88:103484. doi:10.1016/j.eclinm.2025.103484. PMID 40979218. Open access (CC BY 4.0). Table 1: PECARN predictors for age under 2 years and 2 years or older; 3012 children; sensitivity 74.1% for PECARN 2 years or older. pmc.ncbi.nlm.nih.gov/articles/PMC12447897/
Alsuwais S, Kennedy C, Bressan S, Lyttle M, Body R. An update on paediatric traumatic brain injury in the emergency department: a narrative review. Eur J Pediatr. 2025;184(8):523. doi:10.1007/s00431-025-06345-9. PMID 40751746. Open access (CC BY 4.0). Table 4: PECARN high-risk (CT recommended), moderate-risk (CT or observation) and no-risk-factor (CT not recommended) groups. pmc.ncbi.nlm.nih.gov/articles/PMC12317874/
Sawaya RD, Wakil C, Wazir A, et al. Does implementation of the PECARN rules for minor head trauma improve patient-centered outcomes in a lower resource emergency department: a retrospective cohort study. BMC Pediatr. 2020;20(1):439. doi:10.1186/s12887-020-02328-x. PMID 32943022. Open access (CC BY 4.0). Table footnotes: definitions of severe mechanism of injury, altered mental status and signs of basilar skull fracture. pmc.ncbi.nlm.nih.gov/articles/PMC7499971/
Cho S, Hwang S, Jung JY, et al. Validation of Pediatric Emergency Care Applied Research Network (PECARN) rule in children with minor head trauma. PLoS One. 2022;17(1):e0262102. doi:10.1371/journal.pone.0262102. PMID 35041677. Open access (CC BY). 448 children; sensitivity 100% in both age groups; specificity 81.1% (under 2 years) and 74.6% (2 years or older). pmc.ncbi.nlm.nih.gov/articles/PMC8765658/
Kuppermann N, Holmes JF, Dayan PS, et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet. 2009;374(9696):1160-1170. doi:10.1016/S0140-6736(09)61558-0. PMID 19758692. Original paper (cited; the predictors used here are taken from Wickbom 2025 and Alsuwais 2025, CC BY). doi.org/10.1016/S0140-6736(09)61558-0

Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-02. Spotted an error? See About.