Otitis externa; malignant

Alternative names:

malignant otitis externa; osteomyelitis of the skull

Definition:

A disorder involving inflammation and damage of the bones and cartilage of the base of the skull, caused by spread of infection from external ear infection.

Causes, incidence, and risk factors:

Malignant otitis externa is a relatively uncommon complication of both acute otitis externa and chronic otitis externa (swimmer's ear, external ear infection). It occurs in approximately 5 out of 10,000 people. Diabetics and persons whose immune system are compromised from diseases or medications are particularly susceptible to malignant otitis externa.

The infection of external otitis, often caused by difficult-to-treat bacteria such as Pseudomonas, spreads from the floor of the ear canal to the adjacent tissues and into the bones of the base of the skull. The bones may be damaged or destroyed from the resulting infection and inflammation. The infection may further spread and affect the cranial nerves, the brain, or other parts of the body.