Which of the following is NOT a common sign of a skull fracture?

Superficial scalp lacerations are not specifically considered a common sign of a skull fracture because they can occur independently of any cranial injury. Scalp lacerations may arise from various causes such as blunt trauma, but they do not necessarily indicate that a fracture of the skull has occurred. In contrast, the other signs listed are directly associated with skull fractures.

For instance, bruising of the mastoid process (known as Battle's sign) and ecchymosis around the eyes (raccoon eyes) are both classic indicators of a possible skull fracture, particularly involving the base of the skull. These signs often reflect underlying injuries to the cranial bones. A noted deformity to the skull typically suggests structural damage, indicating that a fracture has occurred. Therefore, while scalp lacerations can present with any head injury, they are not uniquely or commonly indicative of a skull fracture itself, making them stand out as an exception among the other options provided.