A positive halo sign on a dressing confirms leakage of CSF from which source?

• A. Indicates hearing loss
• B. Sign of meningitis
• C. Confirms leakage of CSF from the ears
• D. Indicates otitis externa

Answer: (C)

A halo sign on a dressing indicates that cerebrospinal fluid is leaking. In head trauma, CSF can escape through the ears or nose when the base of the skull is injured. The CSF creates a pale yellow ring around the central blood stain on the dressing because CSF diffuses into the surrounding fluids. This finding points to CSF otorrhea, meaning the source is leakage from the ears. It’s not a sign of hearing loss, meningitis by itself, or otitis externa—the halo simply confirms CSF leakage, with meningitis being a potential complication if the leak isn't managed.