Malignant external otitis: the use of oral ciprofloxacin

Malignant external otitis: The shifting treatment paradigm

IMPORTANCE

Malignant external otitis (MEO) is an aggressive infection occurring in immunocompromised hosts. Increasing antimicrobial resistance is making the disease more difficult to treat.

OBJECTIVE

Determine if there has been a shift in the microbiology and outcomes of MEO.

DESIGN

A retrospective case series at a tertiary care institution.

SETTING

Inpatient and outpatient tertiary care hospital.

PARTICIPANTS

12 cases of recent MEO were reviewed.

MAIN OUTCOMES AND MEASURES

The primary outcome was progression of disease. Secondary outcomes were drug resistance and complications of MEO.

RESULTS

Only 4 patients were cured of MEO. Four patients expired during the study period and at least one of these deaths was a direct result of the MEO. 7 patients developed Cranial nerve palsies, and 3 patients developed abscesses.

CONCLUSIONS

Select cases of MEO now require multi-drug and long-term parenteral antibiotic therapy with extended hospital stays.

Necrotising otitis externa: clinical profile and management protocol

BACKGROUND

Necrotising otitis externa, which is typically seen in elderly diabetics, is a severe infective disorder caused by Pseudomonas aeruginosa. There is lack of standard management policy for necrotising otitis externa, hence this study attempted to frame a protocol for management based on clinical parameters.

METHOD

A retrospective study of 27 patients with necrotising otitis externa was conducted over 6 years in a tertiary care hospital. Data were analysed with regards to demographic characteristics, clinical features, investigations, staging and treatment modalities.

RESULTS

Out of 27 patients, 26 were diabetics. The commonest organism isolated was P aeruginosa, which was sensitive to third generation cephalosporins and fluoroquinolones. Nine patients had cranial nerve involvement. Twelve of 15 patients treated with medical therapy recovered, as did 11 of 12 patients that underwent surgery.

CONCLUSION

A high index of suspicion, early diagnosis and prompt intervention are key factors to decrease morbidity and mortality. Fluoroquinolones, third generation cephalosporins and surgical debridement are the mainstay of treatment.

The changing face of malignant (necrotising) external otitis: clinical, radiological, and anatomic correlations

Malignant (necrotising) external otitis is an invasive infection of the external auditory canal. Although elderly patients with diabetes remain the population most commonly affected, immunosuppressed individuals (eg, from HIV infection, chemotherapy, etc) are also susceptible to malignant external otitis. Pseudomonas aeruginosa is isolated from the aural drainage in more than 90% of cases. The pathophysiology is incompletely understood although aural water exposure (eg, irrigation for cerumen impaction) has been reported as a potential iatrogenic factor. The typical patient presents with exquisitely painful otorrhoea. If untreated, cranial neuropathies (most commonly of the facial nerve) can develop due to subtemporal extension of the infection. The diagnosis of malignant external otitis is based on a combination of clinical findings, an increased erythrocyte sedimentation rate, and radiographic evidence of soft tissue with or without bone erosion in the external canal and infratemporal fossa. Treatment consists of prolonged administration (6-8 weeks) of an antipseudomonal agent (typically an orally administered quinolone). With the introduction and widespread use of both oral and topical quinolones, there are reports of less severe presentation of malignant external otitis and even the emergence of ciprofloxacin resistance. Reservation of systemic quinolones for the treatment of invasive ear infections is recommended.

Malignant otitis externa with optic neuritis

Malignant otitis externa is a serious condition that presents difficulties in treatment, and also in monitoring its progress. A case of malignant otitis externa with optic neuritis is presented that remained refractory to standard treatment but was cured by adjuvant hyperbaric oxygen therapy. This is the only reported case that has survived this disease with optic neuritis. The usefulness of imaging techniques in this condition is discussed, as well as the ESR, in evaluating the effectiveness of treatment.

Ciprofloxacin. A review of its pharmacological profile and therapeutic use in the elderly

Ciprofloxacin belongs to the fluoroquinolone class of antimicrobial agents which primarily inhibit bacterial DNA gyrase. It is effective after oral or intravenous administration, demonstrating potent antibacterial activity against most Gram-negative, and many Gram-positive bacteria. Although most bacterial strains have remained susceptible to the drug, low rates of resistance have been observed in some strains of Pseudomonas aeruginosa and enterococci and higher rates in methicillin-resistant Staphylococcus aureus. Ciprofloxacin attains concentrations in most tissues and body fluids sufficient to inhibit the majority of susceptible pathogens. Its pharmacokinetic profile in the elderly (> or = 65 years) is broadly similar to that reported in younger persons, although plasma concentrations are higher, and renal clearance is decreased in elderly persons. Ciprofloxacin is an effective treatment for those infections most common in elderly patients, including infections of the urinary tract, lower respiratory tract, skin and soft-tissues, and bone and joints, and is an effective agent for prophylaxis in transurethral surgery. Orally administered ciprofloxacin appeared to be at least as effective as alternative orally administered antimicrobial agents (trimethoprim, cotrimoxazole [trimethoprim/sulfamethoxazole], amoxicillin, amoxicillin/clavulanic acid) and also as effective as various parenteral agents (ceftriaxone, cefamandole, ceftazidime, cefotaxime) in a small number of comparative clinical trials. However, further studies are needed to clarify the comparative efficacy of ciprofloxacin with that of other oral and parenteral agents in the elderly. Initial trials have also indicated therapeutic efficacy of oral ciprofloxacin in malignant external otitis and bacterial prostatitis. Nevertheless, with its good tolerability profile and potent antimicrobial activity following oral administration, ciprofloxacin appears to offer a valuable alternative for treating various acute and chronic infections in elderly patients. Causative pathogens are frequently multiresistant in this patient group, and ciprofloxacin avoids or minimises the need for parenteral therapy.

Malignant external otitis: management policy

Malignant external otitis is a progressive pseudomonal infection of the external auditory canal and adjacent structures. In the literature there is no unified policy regarding the management of malignant external otitis. The development of an effective nuclear scanning method and antibiotics active against Pseudomonas aeruginosa have helped in formulating our management policy. A review of four years personal experience with this condition is presented. All of our cases were cured from the disease with no fatality. Gallium citrate scans showed that antipseudomonal treatment should continue for up to three months.

Otitis externa malignum

Twelve elderly diabetic patients with Pseudomonas otitis externa malignum were successfully treated with norfloxacin as monotherapy for 2-5 weeks, using 400 mg b.i.d. Patients tolerated the courses with no side effects, except some drowsiness in two patients, and all completed the course. The bacteriological and clinical cure rate was 100%, without resorting to surgery.

Use of quinolones for treatment of ear and eye infections

Malignant otitis externa is a severe, necrotizing infection of the external auditory canal which is sometimes fatal. The traditional antimicrobial treatment has usually been the combination of an antipseudomonal beta-lactam and an aminoglycoside, given intravenously for 4 to 8 weeks. Over 100 patients have been treated with a fluoroquinolone alone, most commonly ciprofloxacin given by mouth in a dosage of 750 mg b.i.d. for 6 to 12 weeks. About 90% of patients have been cured. Treatment with a quinolone has the advantage over older treatments that it can be given orally and has a low rate of side-effects. The ocular penetration of the fluoroquinolones has been studied in patients with unifected eyes. After the administration of a single dose of ciprofloxacin, pefloxacin, ofloxacin or norfloxacin, penetration into the aqueous humor, expressed as the ratio of the peak concentration in the aqueous humor to that in the serum, is about 20%. The penetration of ciprofloxacin into the vitreous humor, based primarily on the data from one report, is about 20%. The concentrations are likely to be higher after repeated doses or in the inflamed eye. Whether the concentrations achieved will be adequate for therapeutic or prophylactic purposes has not been determined.

Biocompatible implantable antimicrobial release for necrotizing external otitis

The efficacy of a biocompatible, surgically implantable, antimicrobial release system (IARS) as the exclusive antimicrobial therapy of necrotizing external otitis (NEO) was evaluated in six NEO patients. Gentamicin incorporated polymethyl-methacrylate beads were implanted, following surgical debridement and were removed two months later. Post-implantation alleviation of clinical symptoms: pain, periauricular tissue swelling, otorrhoea, eradication of pseudomonal infection (100 per cent) and substantially shortened hospitalization (4-15 days) were the salient results of this therapeutic modality. Three patients recovered. Two patients who died, one of sudden cardiac arrest and the other of paralytic ileus, 15 and 60 days post-operatively while the beads were still implanted, were symptomless. Recurrence was seen in one patient with early bead extrusion. Ipsilateral sensorineural hearing loss (one patient) and external meatal stenosis were the main complications. IARS appears to offer an effective alternative to long-term systemic antibiotic administration for the eradication of NEO-pseudomonal infection in patients who are sensitive, develop resistance, or when quinolone medical treatment has failed or is contra-indicated.