Diseases of The Ear
Malignant otitis externa is characterized: [PGI Dec 2012]
|A||Caused by pseudomonas aeruginosa|
|B||Malignancy of external auditory canal|
|C||Granulation tissue is seen in the floor of extra auditory canal|
|D||Radiotherapy can be given|
|E||Gallium scan is helpful for monitoring treatment|
Ref. Dhingra 5th/ed pg 58, 6th/ed p 52 Scott's Brown 7th/ed vol 3 pg 3336-3339; Harrison 7 7th/ed pg 208
Malignant Otitis Externa : Brief summary
• It is an inflammatory condition of external ear,?
• Most commonly caused by Pseudomonas.
• Other organisms responsible are: S. aureus, S. epidermidis, Aspergillus, Actinomyces.
• Seen in elderly diabetics Q /immuno compromised patients Q /patients on immunosuppressive drug. Q
• Called as malignant because it behaves like a tumor in causing destruction of tissues of canal and pre and post auricular region
• by various enzymes. Q
• Characterised by presence of granulation tissue in external auditory canal Q, at the junction of bony and cartilaginous part. Q
• It is very painful
• It can spread to base of skull and temporal bone (causing osteomyelitis of temporal bone).
• As the infection spreads to temporal bone, and base of skull, it may involve cranial nerves (most common being facial nerve).
• Gold standard for diagnosis: positive technetium 99 bone scan.
• Treatment: high dose IV antibiotics
• Cefepime lteftazidine (3rd generation cephalosporin).
• Antipseudomonal penicillin with an aminoglycoside f.f1uoroquinolone.