Head Bumps in Infants: Identifying Cephalhematoma, Caput Succedaneum, Subgaleal Hematoma, and Pilonidal Cysts

A round, quarter-sized, movable bump on an infant's head has several possible causes. Accurate diagnosis guides management.

1. Cephalhematoma

• Cause: Birth trauma (forceps, vacuum, prolonged labor) → subperiosteal hemorrhage.
• Features: Well-defined, fluctuant, does not cross suture lines. Appears hours–days post-birth. Not painful.
• Course: Resolves weeks–months; may calcify. Monitor for anemia, jaundice (bilirubin load).

2. Caput Succedaneum

• Cause: Pressure on presenting part during labor → scalp edema.
• Features: Diffuse, pitting edema, crosses suture lines. Present at birth. Not painful.
• Course: Resolves in days.

3. Subgaleal Hemorrhage

• Cause: Birth trauma (vacuum/forceps) → bleeding in subgaleal space (loose areolar tissue between galea aponeurotica and periosteum).
• Features: Fluctuant, crosses sutures, may extend to orbits/neck. Can cause significant blood loss (hypovolemia, coagulopathy).
• Urgency: Monitor vitals, Hgb, coagulation. May need transfusion. Neurosurgery consult if expanding.

4. Pilonidal Cyst/Sinus

• Location: Sacrococcygeal midline (base of spine), not top of head.
• Features: Pit/sinus, may drain, become infected (abscess). Rare in infants; more common adolescents/young adults.

Other Considerations

• Dermoid/epidermoid cyst (midline, nuchal/occipital).
• Lymph node (occipital, postauricular).
• Skull fracture (if trauma).
• Hemangioma (vascular, blanchable).

Action

Any new, changing, or symptomatic head bump in an infant warrants pediatric evaluation. Imaging (US, CT) if diagnosis uncertain or subgaleal bleed suspected.