Malignant otitis externa
Osteomyelitis of the skull; Otitis externa - malignant; Skull-base osteomyelitis; Necrotizing external otitisMalignant otitis externa is a disorder that involves 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 not common.
Risks for this condition include:
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Chemotherapy
Chemotherapy
The term chemotherapy is used to describe cancer-killing drugs. Chemotherapy may be used to:Cure the cancerShrink the cancerPrevent the cancer from ...
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Diabetes
Diabetes
Diabetes is a long-term (chronic) disease in which the body cannot regulate the amount of sugar in the blood.
Read Article Now Book Mark Article - Weakened immune system
External otitis is often caused by bacteria that are hard to treat, 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 swelling may damage or destroy the bones. The infection may affect the cranial nerves, brain, or other parts of the body if it continues to spread.
Symptoms
Symptoms include:
- Ongoing drainage from the ear that is yellow or green and smells bad.
Drainage from the ear
Ear discharge is drainage of blood, ear wax, pus, or fluid from the ear.
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Ear pain deep inside the ear. The pain may get worse when you move your head.
Ear pain
An earache is a sharp, dull, or burning pain in one or both ears. The pain may last a short time or be ongoing. Related conditions include:Otitis m...
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Hearing loss.
Hearing loss
Hearing loss is being partly or totally unable to hear sound in one or both ears.
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Itching of the ear or ear canal.
Itching
Itching is a tingling or irritation of the skin that makes you want to scratch the area. Itching may occur all over the body or only in one location...
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- Trouble swallowing.
- Weakness in the muscles of the face.
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) exam may show that the cranial nerves are affected.
If there is any drainage, the provider may send a sample of it to the lab. The lab will culture the sample to try to find the cause of the infection.
To look for signs of a bone infection next to the ear canal, the following tests may be done:
Bone infection
Osteomyelitis is a bone infection. It is caused by bacteria or other germs.
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CT scan of the head
CT scan of the head
A head computed tomography (CT) scan uses many x-rays to create pictures of the head, including the skull, brain, eye sockets, and sinuses.
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MRI scan of the head
MRI scan of the head
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...
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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.
You will need to take antibiotic medicines for a long period of time. The medicines may be given through a vein (intravenously), or by mouth. Antibiotics should be continued until scans or other tests show the inflammation has gone down.
Dead or infected tissue may need to be removed from the ear canal, using a procedure called debridement. In some cases, surgery may be needed to remove dead or damaged tissue in the skull.
Outlook (Prognosis)
Malignant otitis externa most often responds to long-term treatment, especially if treated early. It may return in the future. Severe cases may be deadly.
Possible Complications
Complications may include:
- 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
When to Contact a Medical Professional
Contact your 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:
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Convulsions
Convulsions
A seizure is the physical changes in behavior that occurs during an episode of specific types of abnormal electrical activity in the brain. The term ...
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Decreased consciousness
Decreased consciousness
Decreased alertness is a state of reduced awareness and is often a serious condition. A coma is the most severe state of decreased alertness from whi...
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Severe confusion
Confusion
Confusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...
Read Article Now Book Mark Article - Facial weakness, loss of voice, or difficulty swallowing associated with ear pain or drainage
Prevention
To prevent an external ear infection:
- Dry the ear thoroughly after it gets wet.
- Avoid swimming in polluted water.
- Protect the ear canal with cotton or lamb's wool while applying hair spray or hair dye (if you are prone to getting external ear infections).
- After swimming, place 1 or 2 drops of a mixture of 50% alcohol and 50% vinegar in each ear to help dry the ear and prevent infection.
- Maintain good glucose control if you have diabetes.
Treat acute otitis externa completely. Do not stop treatment sooner than your provider recommends. Following your provider's plan and finishing treatment will lower your risk of malignant otitis externa.
References
Araos R, D'Agata E. Pseudomonas aeruginosa and other pseudomonas species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 219.
Matlock AG, Pfaff JA. Otolaryngology. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 58.
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Ear anatomy - illustration
The ear consists of external, middle, and inner structures. The eardrum and the 3 tiny bones conduct sound from the eardrum to the cochlea.
Ear anatomy
illustration
Review Date: 5/2/2024
Reviewed By: Josef Shargorodsky, MD, MPH, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.