This condition describes otitis externa (inflammation of the ear canal) which progresses to osteomielitis when infection spreads onto the skull base and petrous portion of the temporal bone.

It is most common in elderly diabetic or immunocompromised patients and is usually caused by Pseudomonas Aeruginosa.

Symptoms

Most commonly overwhelming constant deep otalgia (earache) and malodorous discharge from the ear. VII- XII cranial nerves palsies may occur and cause symptoms similar to those with a stroke- facial weakness, hearing loss, difficulties in swallowing and breathing, hoarseness and impaired speech.

Sometimes Malignant Otitis Externa may lead to meningitis, sigmoid sinus thrombosis, brain abscess and death.

This condition should be suspected in patients with granulation tissue at depth of ear canal which does not settle with the usual treatment. The diagnosis often is not considered until cranial nerve palsy has developed. Histological and microbiological examination of granulation tissue, and a high definition CT scan of the head are required to make a diagnosis.(1)

Treatment

Conventional treatment of MOE is with topical, oral and intravenous antibiotics and regular aural toilet by ENT (microscope guided suction of the ear canal. ) with application of topical AB and cauterisation/debridement of granulation tissues. The dose and duration of treatment is decided after discussion with microbiologist and by monitoring clinical response. Often therapy has to be continued for 6 weeks or more. Opiate analgesia often required to control the ear pain. Even with aggressive treatment there is still significant mortality.(1)

HBO application

Recent reports by Davis et al., with dual–modality therapy with antibiotics and Hyperbaric Oxygen Therapy show (HBO) improved success rate of upward of 90 to 100 % (2). Application of HBO has shown to reduce the swelling of damaged tissues, reverses tissue hypoxia, promotes new blood vessels formation hence improves blood supply and speeds up regeneration of tissues damaged by infection. It also enhances the therapeutic effect of antibiotics. Therefore adjuvant HBO therapy should be considered in advanced or recurrent cases of malignant otitis externa.

References:

1- Key Topics in Otolaryngology- N J Roland, R D R McRae,A W McCombe

2- Essential Otolaryngology Head & neck surgery,8th edition- K J Lee.

3- Value of Hyperbaric oxygen in bacterial and fungal malignant external otitis treatment.W Narozny, J Kuczkowski..Eur Arch Otorhinolaryngology (2006)

4- Adjuvant hyperbaric oxygenin malignant external otitis- Davis JC, Gates GA, Davis MG Jr, Mader JT, Dinesman A. Arch Otol Head Neck surg.1992