When to Worry About Scalp Hematoma
You should be most concerned about scalp hematomas that are nonfrontal (temporal/parietal or occipital), large and boggy, or present in infants under 6 months of age, as these characteristics significantly increase the risk of intracranial injury. 1, 2
Age-Specific Risk Stratification
Children Under 2 Years
- Nonfrontal scalp hematoma (temporal, parietal, or occipital) places the child at intermediate risk and warrants serious consideration for CT imaging 1
- Infants aged 0-6 months have the highest risk (OR = 13.5) for intracranial injury when a scalp hematoma is present 2
- A palpable skull fracture beneath the hematoma elevates the child to high-risk status requiring immediate imaging 1
Children 2 Years and Older
- Scalp hematomas are not specifically listed as intermediate or high-risk criteria in this age group by PECARN 1
- However, research demonstrates that nonfrontal and large/boggy hematomas still independently increase intracranial injury risk across all pediatric age groups 2
Hematoma Characteristics That Increase Concern
Location Matters Most
- Temporal/parietal hematomas: 6-fold increased odds of intracranial injury (OR = 6.0) 2
- Occipital hematomas: 5.6-fold increased odds of intracranial injury (OR = 5.6) 2
- Frontal hematomas: Lower risk compared to other locations 2
Size and Consistency
- Large and boggy hematomas: 10-fold increased odds of intracranial injury (OR = 9.9) 2
- Small and localized hematomas: Still carry increased risk but to a lesser degree 2
- The presence of any scalp hematoma increases intracranial injury odds 4.4-fold overall 2
Additional Red Flags Requiring Immediate Action
Beyond the hematoma itself, worry when accompanied by:
- Glasgow Coma Scale (GCS) score ≤14 or altered mental status (agitation, somnolence, repetitive questioning, slow verbal response) 1
- Signs of basilar skull fracture (hemotympanum, Battle's sign, raccoon eyes, CSF otorrhea/rhinorrhea) 1
- Loss of consciousness: Any duration in children ≥2 years; ≥5 seconds in children <2 years 1
- Persistent vomiting (more than once) 1
- Severe mechanism of injury (motor vehicle crash with patient ejection, death of another passenger, or rollover; pedestrian/bicyclist without helmet struck by motorized vehicle; fall >3 feet for children <2 years or >5 feet for older children) 1
- Age >64 years in adults 1
Critical Pitfall: Skull Fracture Doesn't Explain Everything
A common misconception is that ruling out a skull fracture beneath the hematoma eliminates concern. Research shows that only 51% of patients with both scalp hematoma and intracranial injury had an underlying linear skull fracture—meaning 49% had intracranial injury without fracture 2. The association between scalp hematoma and intracranial injury remains significant even after excluding patients with skull fractures (OR = 3.3) 2.
Timing of Presentation
Children presenting >24 hours after injury with isolated scalp hematoma and no neurological symptoms, focal signs, or severe mechanism generally have good outcomes without neurosurgical intervention 3. However, this does not eliminate the possibility of positive CT findings 3. For late presenters without red flags, observation may be appropriate rather than immediate imaging 3.
When Imaging Is Indicated
Based on validated decision rules (PECARN, NEXUS Head CT):
- Mandatory imaging: High-risk features (GCS ≤14, altered mental status, signs of basilar skull fracture, palpable skull fracture in infants) 1
- Strong consideration for imaging: Nonfrontal scalp hematoma in children <2 years, large/boggy hematomas, infants 0-6 months with any hematoma 1, 2
- May observe without imaging: Frontal hematomas in older children (≥2 years) with GCS 15, no loss of consciousness, no vomiting, normal behavior, and non-severe mechanism 1, 3
Rare but Life-Threatening: Massive Subgaleal Hematoma
Watch for rapidly increasing head circumference with progressive soft tissue swelling, which can lead to severe anemia, hemodynamic instability, and death if not recognized 4. This occurs from tearing of emissary veins in the loose areolar tissue beneath the galeal aponeurosis 5. Most cases respond to conservative management with compression bandaging, but surgical drainage is reserved for failed conservative treatment or severe complications 5.