Pediatric Head Injuries: More than Just PECARN?!

Clinical Scenario

A 6-month-old rolls off the couch, bumps his head, and immediately lets everyone know with a loud cry. Now he's back to his usual self—smiling, feeding like a champ, and trying to chew on your stethoscope. The only catch: a large, ominous-looking temporal hematoma that makes his parents' hearts race. They turn to you: "Doc, does our baby need a CT scan?"

PECARN has been THE decision rule for guidance on management of kids with head injuries, but the Infant Scalp Score dives even deeper for babies with scalp hematomas. Which rule should you use in this situation?

Summary

PECARN: well-validated, widely accepted tool to assess head injury risk in children of all ages.

Infant Scalp: adds age- and hematoma-specific nuance, most applicable to children <1 year of age.

Tool Comparison

	PECARN	Infant Scalp
Purpose	Identify children at very low risk of clinically important TBI (ciTBI) to reduce unnecessary CT.	Stratify risk of TBI in infants <2 years with isolated scalp hematomas.
Use When...	Children <18 years with blunt head trauma, GCS ≥14. Separate pathways for <2 yrs and ≥2 yrs.	Infants <24 months with scalp hematoma only (no LOC, vomiting, neuro deficit, etc.).
Scoring	Rule-based: <2 yrs: GCS, LOC, palpable skull fracture, severe mechanism, AMS, non-frontal scalp hematoma, abnormal behavior. ≥2 yrs: GCS, LOC, vomiting, basilar skull signs, severe mechanism, AMS, severe headache.	Point-based (0–8): Age (<3, 3–6, 6–12, 12–24 months) Hematoma size Hematoma location (temporal/parietal, occipital, frontal)
Action	😃 Very low risk: avoid CT. 😐 Intermediate risk: observe vs CT. 🙁 High-risk: CT recommended.	Stratifies into low or high risk -> guides CT vs. observation.
Performance	Sensitivity >99% for ciTBI; specificity ~50%. Widely validated in large cohorts.	AUC ~0.80 for ciTBI in this subgroup; refines PECARN decisions in isolated scalp cases.
Workup	Low risk: no CT. Intermediate: observe vs CT. High risk: CT. Clinical judgment + parental input key..	Score <4, imaging may not be necessary. Score ≥4, imaging (usually with a CT) should be considered.
Common Pitfalls	• Confusing ciTBI with any ICI on CT • Over-reliance without considering clinical context and caregiver preference • Babies less than 2 months of age are at higher risk for ciTBI with minor trauma • Always consider non-accidental trauma, especially in infants 4 months and younger	• Only validated for isolated scalp hematomas • Not for cases with LOC, vomiting, neuro deficits • Misuse outside <2 yrs • Always consider non-accidental trauma, especially in infants 4 months and younger
In intermediate-risk cases, consider the caregivers' level of anxiety and preference. After an informed discussion about the risks of cumulative radiation exposure versus the benefits of identifying a possible intracranial injury, it may be reasonable to obtain a CT scan if this shared decision-making helps the family feel safe and supported.

Case Resolution

Although our kiddo looked fantastic—smiling, feeding, and charming the staff—the combination of his age, hematoma size, and location tipped the scales toward imaging when the Infant Scalp Score was applied. A CT was performed and, thankfully, came back negative. With a negative scan, he went home happy, leaving his parents more exhausted than he was.