Here is how to manage/ treat a case of malignant O.E.
- Hospitalization is a must.
- Consultation of infectious diseases specialists.
- Culture and sensitivity should be made before starting antibiotic therapy in order to guide antimicrobial selection.
Bacterial malignant otitis externa:
- Start treatment with Antipseudomonal antibiotics (systemic) as detailed below.
- Recently, Combined theraby (aminoglycosides or third-generation cephalosporins) has been replaced by "Fluoroquinolones".
- Treatment course goes as follows:
- Start with Ciprofloxacin 400mg IV/8 hours, As soon as treatment response is seen, transition to oral 750mg po twice daily should be done.
- Only Ciprofloxacin has aclinical effect, not other fluoroquinolones.
- Poor vascularization of EAC may require higher doses.
- Culture and sensitivity is essential to guide treatment because there is increasing pseudomonal resistance to fluoroquinolones.
List of antibiotics that can be used as anti-pseudomonas with doses:
- Ciprofloxacin: 400mg/ 8hours, IV (as described above).
- Piperacillin-tazobactam (usually combined with an aminoglycoside): 4-6 gm/4-6 hours, IV.
- Ticarcillin-clavulanate (usually combined with an aminoglycoside) : Dose 3g/4 hours, IV.
- Cefepime: 2g/12 hours, IV.
- Tobramycin (combined with an antipseudomonal pencillin): 1-1.66mg/kg/8 hours, IV.
- Gentamicin: the same dose as Tobramycin.
- Ceftazidime: the same dose as Cefepime.
Treatment of Fungal malignant otitis externa
- This kind should be suspected if there is negative cultue and failure of patient's response to antibiotics.
- Drugs of choice are liposomal amphocterin followed by oral itraconazole for up to 12 weeks.
Surgical management (E.N.T):
- Debridement of the EAC.
- Biopsy is mandatory to rule out malignancy.
- Surgical removal of infected bone, just in case of failure of antimicrobial therapy.
Therapies under experiments:
Hyperbaric oxygen (till now, no proved efficacy) can be used in resistant cases as an adjuvant measure.
Monitoring management of malignant otitis externa (Prognosis)
- Examination of the external auditory canal, and assessing soft tissue erythema.
- Cranial nerves examination.
- Lymph node examination: Pre- and post-auricular in addition to cervical.
- Hearing tests should also be done prior to therapy.
B. Monitoring laboratory tests:
- E.S.R: done every week to assess response to treatment course.
- CBC, C7, LFTS: Done during IV antimicrobial therapy to monitor drug side effects.
- Prolonged treatment of 6-8 weeks is usually required depending on clinical symptoms (night pain), physical findings.
- Formal auditological hearing test after completion of treatment.
Common hazards of management
- Fungal infection should be considered if the patient doesn't respond to antibiotics or negative C&S.
- Culture of discharge should be done before starting anti-microbial course.