Necrotizing external otitis. The importance of prolonged drug therapy

Thirty-Day Readmission and Prolonged Length of Stay in Malignant Otitis Externa

OBJECTIVES

To determine independent risk factors for 30-day readmission, prolonged length of stay (PLOS), and discharge to a rehabilitation facility for those with malignant otitis externa.

METHODS

Retrospective cohort study of patients hospitalized with malignant otitis externa (International Classification of Diseases, 9th edition, code 380.14) in the Nationwide Readmissions Database (2013-2014). Overall and disease-specific complication and mortality data were analyzed using chi-squared and multivariate analysis.

RESULTS

There were 1267 cases of malignant otitis externa extracted. A PLOS of ≥8 days (90th percentile) was found in 14.2% (n = 180) of patients, and 13.7% (n = 174) were discharged to a facility. Patients were readmitted within 30 days at a rate of 12.5% (n = 159). The overall rates of uncomplicated and complicated diabetes were found to be 42.1% and 17.8%, respectively. Factors independently associated with PLOS included undergoing a surgical procedure (odds ratio [OR] 2.08, P < .001), and having central nervous system complications (OR 3.21, P < .001). Independent risk factors for disposition to a facility included nutritional deficiency (OR 1.91, P = .029), PLOS (OR 4.61, P < .001), and age 65-79 years (OR 6.57, P = .001). Readmission was independently linked to PLOS (OR 3.14, P < .001). Diabetes was not an independent risk factor for any outcome.

CONCLUSIONS

Thirty-day readmission, PLOS, and ultimate discharge to a rehabilitation facility were common and closely intertwined. Despite the classic association between diabetes and malignant otitis externa, diabetes was not an independent risk factor for any of our outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2220-2228, 2020.

Surgical management of benign necrotizing otitis externa

Benign necrotizing otitis externa (BNOE) is a rare condition of unknown aetiology which is characterized by the formation of an avascular bony sequestrum of the tympanic plate. The vascular supply of the tympanic plate is easily compromized as demonstrated by the development of avascular necrosis in radionecrosis of the tympanic plate and malignant otitis externa. Recognition of BNOE as distinct from malignant otitis externa and carcinoma of the external ear is important as the treatment differs greatly. BNOE also forms an important part of the differential diagnosis of recalcitrant otitis externa.

Management of BNOE has been unclear with long-term medical treatment being advocated. In this series of five patients, the surgical management of four patients with BNOE is described. Surgery was successful in all these patients and is advocated as an alternative to medical management.

Skull base osteomyelitis interpreted as malignancy

Lesions in the skull base may present difficulties in diagnosis primarily because the access needs to be invasive and one has to rely on imaging that may still be misleading. The case presented here illustrates this example in that the patient had abnormalities on computed tomography (CT) and magnetic resonance image (MRI) scans quite convincing of malignancy but which with time proved, essentially through clinical judgment, to be skull base osteomyelitis secondary to malignant external otitis (OME).

Benign necrotizing osteitis of the external auditory meatus

Benign necrotizing osteitis of the external auditory meatus is a rare condition which occurs in non-diabetic healthy people. The aetiology of the necrotic process with the formation of sequestrum in the bony external meatus is unknown. It is important to differentiate this benign process from malignant otitis externa and radionecrosis of the temporal bone as the management of these conditions differs. We present two cases, one managed surgically and the other medically, and review the literature. Immediate surgical excision of the sequestrum is advocated instead of long-term medical therapy and waiting for it to separate spontaneously.

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.

Relapsing malignant otitis externa successfully treated with ciprofloxacin

Two cases are presented, both patients with advanced relapsing malignant otitis externa. The antibiotic ciprofloxacin has strong anti-pseudomonal activity. It was given orally for six months to both patients, following administration of the traditional parenteral antibiotic courses, and in each case the disease has been extinguished. We therefore recommend that the management of patients shown to have malignant otitis externa should include strict diabetic control, regular local aural toilet, gentamicin ear drops and a six week course of parenteral antipseudomonal antibiotic agents (usually gentamicin and azlocillin) together with metronidazole to cover any anaerobic element in the infection. This regimen should be followed by a six month course of oral ciprofloxacin (750 mg b.d.). Indium scans should be used to monitor recovery. We believe that this regimen can significantly reduce the morbidity and mortality of patients suffering from malignant otitis externa with cranial nerve involvement.

Malignant external otitis: insights into pathogenesis, clinical manifestations, diagnosis, and therapy

Malignant external otitis is an infection of the external ear canal, mastoid, and base of the skull caused by Pseudomonas aeruginosa. The condition occurs primarily in elderly patients with diabetes mellitus. Current theories on pathogenesis and anatomic correlations are reviewed. Severe, unrelenting otalgia and persistent otorrhea are the symptomatic hallmarks of the disease, whereas an elevated erythrocyte sedimentation rate is the only distinctive laboratory abnormality. Iatrogenic causes such as administration of broad-spectrum antibiotics and aural irrigation may play a predisposing role in high-risk populations. The disease can result in cranial polyneuropathies (with facial nerve [VII] paralysis being the most common) and death. The mainstay of treatment is administration of antipseudomonal antibiotics for four to eight weeks. Recurrence is common, and mortality remains at about 20 percent despite antibiotic therapy. Given the increasing longevity of diabetic patients, the frequency of this disease is increasing. Internists, family practitioners, and ambulatory care physicians must now be cognizant of the presenting symptoms, while infectious disease specialists and otolaryngologists need to be appraised of strides in diagnosis and therapy. The role of surgery should be minimized. Use of new diagnostic radiologic modalities and new antipseudomonal antibiotics discussed in this review should lead to improved outcome.