Malignant otitis externa

Definition

Malignant otitis externa is a disorder involving infection and damage of the bones of the ear canal and at the base of the skull.

Causes

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.

Risks for this condition include:

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.

Symptoms

Exams and Tests

Your health care provider will look into your ear for signs of an outer ear infection. 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:

Treatment

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.

Outlook (Prognosis)

Malignant otitis externa usually responds to long-term treatment, especially if treated early. It may return in the future. Severe cases may be deadly.

Possible Complications

When to Contact a Medical Professional

Call for an appointment with your health care provider if:

Go to the emergency room or call the local emergency number (such as 911) if you have:

Prevention

To prevent an external ear infection:

Treat acute otitis externa completely. Do not stop treatment sooner than your health care provider recommends. Following your doctor's plan completely will reduce the risk of malignant otitis externa.


Review Date: 8/30/2012
Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Seth Schwartz, MD, MPH, Otolaryngologist, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc

This information should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.