What does the term "raccoon sign" indicate?

The term "raccoon sign" refers specifically to periorbital ecchymosis, which is the discoloration around the eyes that resembles the dark circles often associated with a raccoon. This specific clinical sign is indicative of a basilar skull injury, where blood leaks into the tissue surrounding the eyes due to trauma to the skull base.

In cases of a basilar skull fracture, the integrity of the facial bones and surrounding structures may be compromised, leading to the characteristic bruising under the eyes. The presence of this sign often suggests a more serious underlying condition, which could include damage to the venous sinuses or the base of the skull.

While head trauma can be a general factor in many cases, "raccoon sign" specifically points to the nature and location of the injury, emphasizing the association with a basilar skull fracture rather than just any head trauma.