Malignant otitis externa is a disorder involving inflammation and damage of the bones and cartilage at the base of the skull.
Osteomyelitis of the skull; Otitis externa - malignant
Causes, incidence, and risk factors
Malignant otitis externa is caused by the spread of an outer ear infection (otitis externa, also called swimmer's ear). It is an uncommon complication of both acute swimmer's ear and chronic swimmer's ear.
External otitis is often caused by difficult-to-treat bacteria such as pseudomonas. The infection spreads from the floor of the ear canal to the nearby tissues and into the bones at the base of the skull. The infection and inflammation may damage or destroy the bones. The infection may spread more and affect the cranial nerves, brain, or other parts of the body.
A doctor will look into your ear for signs of an outer ear infection (otitis externa). The head around and behind the ear may be tender to touch. A nervous system (neurological) examination may show that the cranial nerves are affected.
If there is any drainage, the doctor may send it to the lab for a culture. The purpose of the culture is to look for bacteria or fungi, usually the bacteria Pseudomonas.
To look for signs of a bone infection next to the ear canal, the following tests may be performed:
The goal of treatment is to cure the infection. Treatment often lasts for several months, because it is difficult to treat the bacteria and reach an infection in bone tissue.
Antibiotics that are effective against the microorganism are given for long periods of time. They may be given through a vein (intravenously), or by mouth. Antibiotics should be continued until scans or other tests show that inflammation has gone down.
Occasionally, surgery to remove dead or damaged tissue (surgical debridement) in the skull is needed.
Malignant otitis externa usually responds to long-term treatment, but it may return in the future. Severe cases may be deadly.
Damage to the cranial nerves, skull, or brain
Return of infection, even after treatment
Spread of infection to the brain or other parts of the body
Calling your health care provider
Call for an appointment with your health care provider if:
You develop symptoms of malignant otitis externa
Symptoms continue despite treatment
You develop new symptoms
Go to the emergency room or call the local emergency number (such as 911) if you have:
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Seth Schwartz, MD, MPH, Otolaryngologist, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.