malignant otitis externa and diabets

Malignant Otitis ExternaDiabetes

ASIF SHAHAN YMDC

Definition:

Malignant otitis externa is an aggressive & potentially life-threating infection of the soft tissues of the external ear & surrounding structures ,quickly spreading to involve the periostium & bone of the skull base.

Malignant otitis externa is a misnomer as it is not a neoplastic process

• The most common and important risk factor for MOE is long standing diabetes.

• People with recurrent attacks of severe MOE should be screened for diabetes if they aren’t already aware of suffering from it.

• Age especially elderly patients• Any condition causing

immunosuppression

Risk Factor

Infection from the EAC spreads

Through the fissures of Santorini, small perforations in the cartilaginous

portion of the EAC

Infection spreads medially to the tympanomastoid suture, and along venous canals and fascial planes

The compact bone of the skull base becomes replaced with granulation

tissue,

Bone destruction

Progressive spread of infection to skull base foramina causes cranial

neuropathies.

Pathology:

Microbiology:• The causative agent - Pseudomonas

aeruginosa ( a gram-negative – aerobe).

• Other bacteria including:• Staphylococcus aureus.• Staphylococcus epidermidis.• Proteus mirabilis , Klebsiella.• Fungal organism is Aspergillus

fumigatus.

Clinical presentation:• Otalgia –throbbing pain and

aggravated by chewing. • Otorrhea – pus discharge - yellow,

yellow-green, foul smelling, persistent.• Fever.• Hearing loss.• Trouble swallowing.• Weakness in the face.• Voice loss.

Physical examination:• Otoscope - purulent otorrhea with a

swollen, tender external auditory canal are hallmarks.

• Granulation tissue is frequently seen on the floor of the canal at the bony–cartilaginous junction.

Diagnosis:• We will screen all patients with

recurrent MOE for diabetes by testing their fasting blood sugar levels or HbA1c.

• History and physical examination.• Laboratory- ESR level, culture swab. • CT scan- sensitive in diagnosing abscess

formation.• MRI- shows changes in soft tissue.• Biopsy – to rule malignance.• Nuclear imaging.

MANAGEMENT

Medical:• All patients with uncontrolled diabetes are to

control their blood sugar levels.• Aural toilet; It is essential to control the

granulation tissues & improve local pain control.• Long-term antibiotic:• For at least 6 to 8 weeks- oral and intravenous

ciprofloxacin (750 mg twice daily).• Fluoroquinolones are active against P aeruginosa, ,• Ceftazidime provide an alternative to ciprofloxacin.• Aminoglycoside • Amphotericin B is the most commonly used

antifungal agent for fungal

Hyperbaric Oxygen (HBO):HBO increases the partial pressure of oxygen, improving hypoxia and allowing greater oxidative killing of bacteria.

Surgical:• For the removal of sequestra, collections

of pus & debridement of necrotized & granulations tissues can be beneficial.

Complications:• Damage to the cranial nerves, skull, or

brain.• Return of infection, even after treatment.• Spread of infection to the brain or other

parts of the body.

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