Definition: what is a malignant (necrotizing) external otitis?
L’malignant otitis externa is also known as necrotizing otitis externa.
“It refers to a rare and extremely dangerous infection of the outer ear, which can extend to the temporal bone (the bone of the skull)”, emphasizes Dr. Laurent Gaillardin, a doctor specializing in otolaryngology (ENT) and cervico-facial surgery. In other words, it isexternal otitis that turns to bone infection (osteomyelitis) and sometimes threatens the vital prognosis of patients.
Note: this type of otitis occurs mainly indiabetics and immunocompromised people.
Cause: where does malignant otitis externa come from?
Malignant otitis externa is usually caused by the bacteria Pseudomonas aeruginosa or to Staphylococcus aureus methicillin resistant (MRSA). It can also be linked to a fungus: theAspergillus.
The initial infection may be related to frequent and untimely manipulation of the external auditory canal, says Dr. Gaillardin. A prolonged stay in water can also be problematic. As well as anatomical deformities that might interfere with the self-cleaning function of the skin and retain moisture and / or secretions.
In all cases, the infection becomes more complicated and spreads to areas near the external auditory canal : cartilage, temporal bone (at the temple), facial nerve, meninges, etc.
Symptoms and diagnosis: how to recognize this otitis?
Malignant otitis externa is characterized by severe, persistent pain (we speak of otalgia). Impossible to ignore this symptom. Patients may also experience:
- of itching at ear level;
- of one clear or purulent discharge (otorrhoea), sometimes nauseating;
- and/or redness in the ear canal.
“Sometimes we see the presence of ‘pimples’ in the infected ear (granulations)”, says Dr. Gaillardin. And in the most serious cases, it is even possible to see exposed bone in the ear canal (usually at the junction of the bony and cartilaginous external auditory canal).
What regarding deafness? Malignant otitis externa can actually be associated with conductive hearing loss of varying importance. Tinnitus and vertigo may also occur.
How to diagnose this ear infection?
The diagnosis of malignant otitis externa necessarily begins with clinical examination of the ear canal using an otoscope. Other examinations can confirm or invalidate the diagnosis:
- a computed tomography (CT) of the temporal bone (which demonstrates bone demineralization);
- a culture of discharges (which makes it possible to identify the germs involved);
- and/or a biopsy (which eliminates the risk of cancer).
Is it serious (spoiler: nothing to do with cancer)?
“Malignant otitis externa is not cancerous, insists Dr. Gaillardin. On the other hand, it must be taken very seriously and treated quickly to limit complications, even life-threatening.”
What are the main complications?
If malignant otitis externa is well established, patients may be plagued by paralysis of the nerves of the face and head.
Diabetics and immunocompromised: how to avoid this type of otitis?
Several measures can limit the risk of occurrence of otitis externa:
- use earplugs during swimming, showers, baths, hammams, etc.;
- dry your ears properly following a stay under water to avoid any maceration in the ear canal;
- ban the use of cotton swabs to clean his ears (prefer spray or ear cleaners);
- treat skin diseases which occur near the ears and avoid scratching.
In addition, people with diabetes must regularly monitor their diabetes to limit any complications.
Treatment: how to treat necrotizing otitis externa?
Management of malignant otitis externa depends on stage of infection.
“In the event of loco-regional complications, patients are hospitalized as quickly as possible. Treatment includes the administration ofintravenous antibioticsthe pose of specific dressings in the ear and the realization of local treatments to remove dead skin and soothe the inflammatory tissue,” says Dr. Gaillardin. If possible, doctors also recommend stopping drugs that inhibit the immune system. Hospitalization can last several weeks.
Milder infections can be treated with antibioticsoral and hyperbaric oxygen therapy sessions. Of the regular cleansing sessions at ENT allow to clean the auditory canal, until the infection is overcome. Surgery is usually unnecessary, but surgical debridement can be performed if the infection is extensive. At the same time, level 1 analgesics (such as paracetamol or aspirin) et 2 (such as codeine or tramadol) can fight pain in parallel.
