Osteomyelitis of the skull; Otitis externa - malignant; Skull-base osteomyelitis; Necrotizing external otitis DefinitionMalignant otitis externa is a disorder that involves infection and damage of the bones of the ear canal and at the base of the skull. CausesMalignant 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:
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. SymptomsSymptoms include:
Exams and TestsYour 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:
TreatmentThe 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 ComplicationsComplications may include:
When to Contact a Medical ProfessionalContact your provider if:
Go to the emergency room or call the local emergency number (such as 911) if you have:
PreventionTo prevent an external ear infection:
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. ReferencesAraos 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. | |
| |
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. The information provided herein 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. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | |
| |
Ear anatomy
