ABSTRACT
Osteomyelitis of the lateral skull base may be divided into two main conditions: necrotising otitis externa (NOE) and petrous apicitis. NOE is much rarer than otitis externa, but should be considered in patients who have been diagnosed with otitis externa who fail to resolve, particularly those who fit the typical demographic group. NOE is infection of the external auditory meatus and neighbouring temporal bone, which may spread through the fissures of Santorini and osseocartilagenous junction to involve the rest of the temporal bone and jugular foramen. NOE is most commonly caused by Pseudomonas aeruginosa. It may also be caused by other bacteria, including Staphylococcus aureus, E. coli, Proteus mirabilis and fungal species. Petrous apicitis is rarer still. Both conditions have the potential to cause significant disability or mortality and so it is important to consider the diagnosis and treat them appropriately as soon as possible.
