Basal skull fracture

Clinical features may suggest a basal skull fracture even in the absence of a positive skull x-ray.

Evidence of anterior fossa fracture:

• CSF rhinorrhoea:
  • due to damage to the cribriform plate
  • this often requires formal dural repair
    
    
• bilateral periorbital haematoma:
  • bruising limited to the orbital margins indicates blood tracking from behind
    
    
• subconjunctival haemorrhage where the posterior margin cannot be seen

Evidence of petrous temporal fracture:

• bleeding from the external auditory meatus
  
  
• CSF otorrhoea:
  • through a torn tympanic membrane
  • usually a linear injury which does not require formal dural repair
    
    
• Battle's sign:
  • bruising over the mastoid
  • may take 24-48 hr to develop

A basal skull fracture provides a route for infection. Antibiotics are given to prevent meningitis; the course lasts at least seven days, or if there is a CSF leak, until seven days after this has ceased.

NICE state that (1)

Base of open or depressed skull fracture or penetrating head injury

• signs include clear fluid running from the ears or nose, black eye with no associated damage around the eyes, bleeding from one or both ears, bruising behind one or both ears, penetrating injury signs, visible trauma to the scalp or skull of concern to the professional

Reference:

• NICE (June 2017). Head injury: assessment and early management