Otitis externa is a common ear infection that is also known as “swimmer’s ear.” It develops in the inner ear. In some cases, otitis externa can spread to the outer ear and surrounding tissue, including the bones of the jaw and face. This infection is known as malignant otitis externa.
Although malignant otitis externa shares part of its name with swimmer’s ear, the condition is not caused by water remaining in the ear canal. The condition is caused by bacteria such as Pseudomonas aeruginosa.
Malignant otitis externa is an aggressive infection rather than a malignancy (cancer). An alternative name for malignant otitis externa is necrotizing external otitis. If left untreated, malignant otitis externa can be a life-threatening condition.
Malignant otitis externa is not commonly a complication of swimmer’s ear. Typically, the condition is associated with health problems that can weaken your immune system. Examples include:
When aggressive bacteria enter the ear canal of a patient with a compromised immune system, the body is unable to ward off infection. Once the bacteria cause an infection, the infection can damage the tissue of the ear canal, as well as the bones at the base of the skull. If left untreated, the infection can spread to the brain, cranial nerves, and other parts of the body.
The symptoms of malignant otitis externa are easily recognizable. They can include:
- yellow or green drainage from the ear that is persistent and foul-smelling
- ear pain that gets worse when moving the head
- hearing loss
- persistent itching in the ear canal
- difficulty swallowing
- weakness in the facial muscles
- loss of voice (laryngitis)
If any of these symptoms develop, contact your doctor immediately. Early treatment will help stop the spread of the infection. This will reduce other health complications that result from the infection.
To determine if you have malignant otitis externa, your doctor will complete a physical exam. The exam will include a complete health history to identify underlying conditions that may have compromised your immune system.
During the exam, your doctor will look into your ear to see if there is an infection. Your doctor will also examine your head and behind your ear. If there is drainage from the ear, your doctor may take a sample (culture) of the drainage. This sample will be sent to a lab for analysis. This will help identify the bacteria causing the infection.
If you have malignant otitis externa, your doctor may order additional tests to see if the infection has spread. Such tests would include:
- a neurological exam
- a CT or MRI (imaging) scan of the head
- a radionuclide scan
Treatment for malignant otitis externa typically involves antibiotic therapy. The condition can be difficult to treat. As such, you may need to remain on antibiotics for several months. If your condition is severe, antibiotics may need to be delivered intravenously (through a vein in your arm). Treatment must be continued until tests show that the infection is cured.
If significant tissue damage has occurred as a result of the infection, surgery may also be required. Surgery is sometimes used to remove damaged tissue. Your doctor will tell you if you need surgery. Surgery is performed after the infection has been cured.
Treatment is usually effective, making the outlook of your recovery quite good. However, if you have a compromised immune system, the infection may return.
Recurrent infections can cause damage to the cranial nerves and brain. Spread of the infection to the brain is rare, but it may result in permanent injury and even death.
The best thing you can do to prevent malignant otitis externa is to treat all swimmer’s ear infections until they are gone. This means following your doctor’s advice and finishing the complete dose of your antibiotics.
In addition, if you have a compromised immune system, you should take steps to protect your health. For patients with diabetes, this means controlling blood sugar levels. For patients with HIV, this means adhering to medications to prevent the spread of the virus in the body. Protecting your health is important in boosting your immune system and preventing the onset of an infection.