What Is Malignant Otitis Externa?
Otitis externa is the infection of external auditory canal. In some cases, the infection can spread to adjacent structures(bone); then, the infection is called malignant otitis externa. It is most commonly seen in diabetic patients.
Malignant otitis externa, also called necrotizing external otitis, is a serious condition of the ear and requires urgent treatment. In malignant otitis externa, there is an infection of the ear canal and the adjacent structures. It can lead to serious life-threatening conditions if it is not treated immediately. This disease can cause an infection of the bones of the skull, which starts as a simple external ear infection. The spread of the infection from the external auditory canal to the skull base can be through various routes, like the osseous canal towards the mastoid process posteriorly or towards the temporomandibular joint, parotid gland, and cervicofacial spaces anteriorly. Malignant otitis externa can cause many serious complications like cranial nerve involvement and has an increased rate of morbidity and mortality.
Even though malignant otitis externa is not very common at present due to the development of various antimicrobials and other drugs, this condition is not completely eliminated to categorize it as a rare disease.
What Causes Malignant Otitis Externa?
The common causative organism of malignant otitis externa is Pseudomonas aeruginosa. Also, fungi like Aspergillus fumigatus can cause this condition.
Malignant otitis externa is not just a complication of otitis externa. This can occur in patients who are immunocompromised or patients who take immunosuppressants.
1. Diabetes -
This is due to immune dysfunction seen in diabetic patients. Diabetic patients have compromised responses to antimicrobial agents, and the pH of the ear wax of these patients is higher than that of normal people. The prevalence of malignant otitis externa in both type 1 and 2 diabetic patients is the same.
2. Immunosuppressed Patients (Like Patients With HIV, Chemotherapy, Etc.) -
Patients with immunosuppression are more susceptible to malignant otitis externa and have worse outcomes when compared to patients with diabetes.
When someone has compromised immunity, and then aggressive bacteria enter the ear canal, the body will find it difficult to fight off them. In such cases, the infection can cause damage and spread from the ear canal to the bones at the base of the skull. If still, the condition is untreated, then the infection can spread from there to the brain, cranial nerves, and other parts of the body.
What Are the Signs and Symptoms of Malignant Otitis Externa?
The signs and symptoms are easy to identify, and they are:
-
Foul-smelling greenish-colored discharge from the ear.
-
Ear pain which gets worsens on moving the head.
-
Continuous itching in the ear canal.
-
Difficulty in swallowing.
-
Swelling around the ear.
-
Redness of the skin around the ear.
-
Weakness of the muscles of the face.
-
Hearing loss.
If you notice any of these symptoms, consult your doctor immediately, as the spread can be limited when the treatment is started at the earliest. This will also decrease the chance of developing other complications.
How Is Malignant Otitis Externa Diagnosed?
The healthcare provider will do a physical examination and take a detailed history of the present condition. This will help the doctor to understand the underlying condition which has resulted in the infection.
Also, during the physical checkup, the doctor will examine your ear for ear infections. In case of drainage from the ear, the doctor will take samples and send for a culture of the drainage. This will help to identify the bacteria involved.
The doctor will also advise additional tests for the diagnosis, such as;
-
A CT (computed tomography) scan of the head.
-
MRI (magnetic resonance imaging) scan of the head.
-
Technetium Tc 99m methylene diphosphonate bone scanning.
What Are the Possible Complications of Malignant Otitis Externa?
The complications associated with malignant otitis externa are:
-
Damage to cranial nerves, structures of the brain, and skull bone.
-
Recurrence of the infection.
-
Spread of infection to the brain and other body parts.
How Is Malignant Otitis Externa Managed or Treated?
The management of malignant otitis externa involves the following:
-
Antibiotics- The treatment of malignant otitis externa is done with antibiotics. Even though it is difficult to treat this condition, the duration of the antibiotic therapy could be as long as several months. The antibiotic treatment needs to be administered intravenously in case of severe infection and needs to be treated till the infection subsides.
-
Surgical Therapy- Surgical therapy is advised for patients whose management with medicines has been found to be ineffective. The surgery involves the disposal of the damaged tissue. Surgery is performed once the infection subsides.
What Is the Prognosis of Malignant Otitis Externa?
The prognosis of malignant otitis externa in patients with diabetes is poor. The other factors which resulted in a poorer prognosis are:
-
Involvement of facial nerves.
-
Involvement of additional cranial nerves.
-
Bilateral symptoms.
-
When the infection is caused by Aspergillus.
Elderly patients with malignant otitis externa had more chances of developing complications and had a higher mortality rate compared to younger patients.
How Can Malignant Otitis Externa Be Prevented?
In case you have a swimmer’s ear treat the condition enough so that the infection is completely cured. Follow the doctor’s instructions and complete the dosage of the medicine.
In case you have diabetes, take adequate measures to keep your sugar levels in the normal range. In case you have other immunocompromising conditions take enough care to avoid infections.
Conclusion
Malignant otitis externa is a condition that affects the ear and can spread to infect the skull and other parts of the body. It is an aggressive condition and needs immediate treatment; otherwise, the infection can spread fastly to other parts of the body. In case you have any of the symptoms of malignant otitis externa, seek medical help immediately, as the prognosis of the disease will depend on how early the diagnosis is made.
