What is the Best Test for Diagnosis and Monitoring Treatment Response in Malignant Otitis Externa?

Evaluation of the clinical and radiological features of patients with Malignant otitis externa (MOE)

INTRODUCTION

Malignant otitis externa (MOE) is a life-threatening infection of the external auditory canal and temporal bone.

OBJECTIVE

This study is designed to identify the clinical features, predisposing factors, radiological findings, complications, diagnoses, and management of MOE patients.

STUDY DESIGN

Retrospective cross-sectional study.

SETTING

Loghman-e-Hakim Hospital, Tehran, Iran.

METHODS

The study included 40 patients diagnosed with MOE from 2011 to 2023. The data extracted from medical records included demographic data, clinical signs and symptoms, radiological findings, laboratory data, predisposing factors, complications, treatments, and outcomes. Out of 37 patients, 21 were followed up.

RESULTS

The study found that the mean age of patients was 62.24 ± 11.44 years, with 62.2% being male. Otalgia and otorrhea were the most commonly reported symptoms, and mastoiditis was the most common radiological finding. Bone erosions and osteomyelitis were other important complications. Vascular complications were also observed in 7 patients. The study also found that most patients had underlying conditions such as diabetes mellitus, hypertension, ischemic heart disease, and renal disease. One patient passed away during hospitalization, while others improved and were discharged. Then, at follow-up, 11 patients died, mainly due to the progression of underlying disorders including cardiac, and renal manifestations.

CONCLUSION

Based on our findings, although MOE most commonly occurs in poorly-controlled diabetic or immunocompromised patients, it can also occur in individuals without known conditions. Furthermore, increasing the age and severity of DM could lead to more complications. In terms of medical therapy, coverage of gram-positive bacteria and an antipseudomonal regimen would be an effective treatment.

Epidemiology and risk factors for extension of necrotizing otitis externa

PURPOSE

Necrotizing otitis externa (OEN) is an aggressive and morbid infection of the external acoustic meatus. What are the risk factors for OEN extension?

METHODS

French monocentric retrospective study (2004-2021), including patients with OEN defined by the association of an inflamed EAM, a positive nuclear imaging, the presence of a bacteriological sample and the failure of a well-followed local and/or general antibiotic treatment. OEN was extensive if it was associated with vascular or neurological deficits, if nuclear imaging fixation and/or bone lysis extended beyond the tympanic bone.

RESULTS

Our population (n = 39) was male (74%), type 2 diabetic (72%), aged 75.2 years and pseudomonas aeruginosa was found in 88% of cases. Complications for 43% of patients were extensive fixation on nuclear imaging, for 21% of them the presence of extensive bone lysis, for 13% the appearance of facial palsy, for 5.3% the presence hypoglossal nerve palsy and for 2.5% the presence of thrombophlebitis or other nerves palsies. 59% of our population had extensive OEN. The diagnosis of the extensive OEN was made 22 days later (p = 0.04). The clinical presentation was falsely reassuring due to easier identification of the tympanic membrane (70% vs 46%, p = 0.17) but associated with periauricular oedema (42% vs 0%), bone exposure (16% vs 0%) and a temporomandibular joint pain (41% vs 12%).

CONCLUSION

Delayed treatment of OEN, identification of clinical bone lysis, especially when the tympanic membrane is easily visualized, and the presence of unbalanced diabetes are potential risk factors for extension of OEN.

Necrotizing external otitis: diagnostic clues in the emergency department

PURPOSE

The assessment of necrotizing external otitis requires a high index of suspicion by the attending physician. The purpose of the study is to determine the accuracy of parameters available at the Emergency Department for the diagnosis of this pathology.

METHODS

Retrospective diagnostic accuracy study. Patients consulting at the Emergency Department for longstanding ear swelling, severe otalgia, and failure to respond to topical treatment were included. Otoscopy, physical examination, CT appearance, and analytical results were tested for the diagnosis of necrotizing external otitis, using nuclear imaging as gold standard. Sensitivity, specificity, likelihood ratios and ROC curves were calculated.

RESULTS

24 patients were included; 13 cases were necrotizing external otitis, and 11 cases were other external ear pathologies. Erythrocyte sedimentation rate and C-reactive protein levels were significantly associated with necrotizing external otitis (AUC 0.92 p < 0.001, and 0.8 p < 0.001). Positive likelihood ratios were 10.15 for values of erythrocyte sedimentation rate over 26 mm/h, and 8.25 for C-reactive protein levels over 10 mg/L. Negative likelihood ratios were 0.08 and 0.28, respectively. These results were significant. The rest of clinical and radiological parameters were less accurate.

CONCLUSIONS

Erythrocyte sedimentation rate and C-reactive protein are useful parameters in the evaluation of a case of longstanding otitis with clinical suspicion of necrotizing external otitis. If any of them is elevated, the probability of suffering this condition is significantly increased. If they are within normal ranges, an alternative diagnosis should be sought.

Management and Outcomes of Necrotizing Otitis Externa: A Retrospective Cohort Study in a Tertiary Referral Center

Objectives

Necrotizing otitis externa (NOE) is a rare infection of the ear that causes osteomyelitis. We aimed to evaluate treatment outcomes and the role of imaging in diagnosing and monitoring disease resolution in a single-center study of patients with NOE.

Methods

In this retrospective cohort study, patients with NOE who were diagnosed and treated in a tertiary otology center in Utrecht, The Netherlands, between January 1, 2013 and August 1, 2022, were included. Data were retrieved from the medical records on demographics, symptoms, physical and diagnostic findings, type and duration of treatment, and course of disease.

Results

A total of 24 cases were included. Patients were often elderly (mean age = 75 years) and diabetic (88%). Pseudomonas aeruginosa was the most commonly found microorganism (63%). Twenty-two cases (92%) received intravenous antibiotic treatment, and 7 cases (29%) received additional systemic antifungal treatment. The mean duration of systemic treatment was 29 weeks. In 20 out of 22 cases (91%), imaging was used to determine the end point of treatment. None of the cases with a total resolution of disease activity (n = 5) on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography imaging at the time of cessation of therapy showed clinical relapse, compared with 1 out of 4 cases on gallium single-photon emission computerized tomography.

Conclusion

Based on the experience from our center, we demonstrated that patients with NOE can successfully be treated with prolonged systemic treatment. Molecular imaging is reasonably successful for disease evaluation and decision-making on the eradication of disease.

Clinical Spectrum and Treatment Response of Malignant Otitis Externa Patients: A Rural Tertiary Care Centre Experience

INTRODUCTION

Malignant otitis externa (MOE) is an invasive external ear infection that has a tendency to spread through the temporal bone and can further progress to involve intracranial structures. Though the prevalence of MOE is rare, high morbidity and mortality are often associated. Complications of advanced MOE include cranial nerve involvement, most commonly facial nerve, and intracranial infections such as abscesses and meningitis.

MATERIALS AND METHODS

In this retrospective case series of nine patients diagnosed with MOE, demographic data, clinical presentations, laboratory data, and radiological findings were reviewed. All patients were followed up for a minimum period of three months after discharge. Outcomes were measured in terms of reduction in obnoxious ear pain (Visual Analogue Scale), ear discharge, tinnitus, need for re-hospitalization, recurrence of disease, and overall survival.

RESULTS

In our case series of nine patients (seven males and two females), six underwent surgery, and three patients were managed with a medical line of treatment. All patients had a significant reduction in otorrhea, otalgia, random venous blood sugars, and improvement of facial palsy implicating good response to treatment.

CONCLUSION

Prompt diagnosis of MOE warrants clinical expertise and aids in preventing complications. A prolonged course of intravenous anti-microbial agents is the mainstay of treatment, but timely surgical interventions in treatment-resistant cases can prevent complications.

Malignant external otitis complicated by spinal cord compression: Case report

Introduction

Malignant otitis externa is a life-threatening infectious pathology that occurs mainly in diabetic patients; in a picture of otorrhea, with facial paralysis. We report the case of a necrotizing otitis externa, treated with antibiotics, which was complicated a few months later by spinal compression.

Observation

This is the case of a 60-year-old patient, diabetic, who presented a painful otorrhea associated to left facial palsy.The diagnosis of necrotizing otitis externa was retained after performing a CT scan of the temporal bone.6 months after medical treatment, the patient became has been complicated by tetraparesis with respiratory distress.

Discussion

Necrotizing otitis externa is an osteitis of the base of the skull, which occurs in the diabetic patient and which starts in the external ear and spreads by contiguity after infection of the temporal bone.It represented clinically by otalgia and purulent otorrhea.The role of imaging is to confirm the involvement and to specify the extension of the lesions. CT scan is useful to evaluate the bone involvement. MRI is the examination of choice for the study of soft tissues and is essential in advanced forms.Its treatment is based on antibiotic therapy for a minimum of 6 weeks.

Conclusion

OEM is an infection occurring in elderly and diabetic patients. Imaging allows to confirm the diagnosis and to carry out the assessment of extension; but also has a great interest in the follow-up of these immunocompromised patients who are subject to complications with insidious evolution.

Emerging themes in necrotising otitis externa: a scoping review of the literature from 2011 to 2020 and recommendations for future research

OBJECTIVE

Necrotising otitis externa is an invasive, infective condition, with minimal evidence underpinning its diagnosis and management. This work aimed to analyse literature from the past decade, to identify emerging themes and important topics for future research.

METHODS

A robust literature search and review were conducted by two researchers. Sixty studies were filtered into the final review. A grounded theory approach was used to identify core themes. Data within these themes formed the basis of the review.

RESULTS

There is no consensus regarding a clinical definition or outcome measures of necrotising otitis externa, and there exists no level 1, 2 or 3 evidence to diagnose, investigate, monitor or treat necrotising otitis externa. Emerging themes in the literature direct researchers to important topics for future clinical trials, including risk factors, microbiological culture, management strategies and radiology.

CONCLUSION

In order to optimise understanding and management of necrotising otitis externa, future research requires robust clinical trials and consistently reported outcome measures.

Predictive value of radiologic studies for malignant otitis externa: a systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of Necrotizing Otitis Externa (NOE) based on radiologic studies.

METHODS

The PubMed, Cochrane, Embase, Web of Science, SCOPUS, and Google Scholar databases were searched. True-positive and false-negative results were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool.

RESULTS

The included studies contained data on 37 studies diagnosed with NOE. The sensitivity of gallium-67, technetium-99m, and Magnetic Resonance Imaging (MRI) was 0.9378 (0.7688-0.9856), 0.9699 (0.8839-0.9927), and 0.9417 (0.6968-0.9913), respectively. For Computed Tomography (CT), the positive criteria consisted of bony erosion alone and bony erosion plus any soft tissue abnormality. The sensitivity of CT based only on bony erosion was 0.7062 (0.5954-0.7971); it was higher 0.9572 (0.9000-0.9823) when based on bony erosion plus any soft tissue abnormality.

CONCLUSION

The diagnostic sensitivity of technetium-99m, gallium-67, and MRI was favorable. On CT, the presence of bony erosion may be a useful diagnostic marker of NOE, but the diagnostic sensitivity will be even higher if the criterion of any soft tissue abnormality is also included; however, care should be taken when interpreting the results. Our study demonstrates the potential utility of radiology studies for diagnosing NOE, but their lack of specificity must be considered, and standardized anatomic criteria are still needed.

LEVEL OF EVIDENCE

2A.

Current management of skull base osteomyelitis

PURPOSE OF REVIEW

Skull base osteomyelitis (SBO) is a life-threatening condition. Due to an aging and increasingly multimorbid population, clinicians are more often challenged with this disease. Yet, there is no consensus on the optimal diagnostic and follow-up management. This review should aid clinicians in decision-making for their patients.

RECENT FINDINGS

Treatment-resistant otalgia or headache is suspicious of SBO. Pseudomonas aeruginosa remains the most common pathogen but clinicians are challenged with increasing rates of sterile or fungal cultures due to previously applied antibiotics/steroids. No single imaging modality is able to detect the full extent of the disease. Whereas functional nuclear imaging with gallium-67 or methylene diphosphonate-technetium-99m was once advocated, its actual benefit is questionable. Newer modalities such as fluoro-D-glucose-positron emission tomography (PET)/computed tomography, PET/magnetic resonance imaging (MRI), or diffusion-weighted MRI seem to be promising in diagnosis and follow-up. Finding the causative pathogen is of utmost importance followed by long-term intravenous antibiotics until the disease has completely resolved. Surgery plays a minor role in treatment but can be helpful in selected cases.

SUMMARY

The numerous challenges in SBO render management difficult, but with a clear work-up including regular clinical, laboratory and imaging examinations, outcome can be improved.

Evaluation and Management of Otalgia

Otalgia can be broadly categorized into primary otologic causes and secondary nonotologic causes. Isolated otalgia in the absence of hearing loss, otorrhea, or abnormal otoscopic findings is typically secondary to referred pain from nonotologic causes, as the sensory nerve supply to the ear arises from 4 cranial nerves and the cervical plexus. The most common causes of primary otalgia are acute otitis media and otitis externa, whereas the most common causes of secondary otalgia are temporomandibular joint disorders and dental pathology. Persistent unilateral ear pain and other alarm symptoms warrant further evaluation for possible neoplasm.

Malignant Otitis Externa: How to Monitor the Disease in Outcome Estimation?

Objective

Malignant otitis externa (MOE) is a serious disease affecting mainly the elderly diabetic patients that may result in mortality. It was aimed to evaluate the relationship between treatment responses and clinical and radiologic parameters among progress of the disease. Secondary aim was to present our clinical outcomes in the treatment of malignant otitis externa.

Method

This study was retrospectively conducted in a single center. Reviewed data included history of complaints, duration of symptoms, addition of hyperbaric oxygen treatment, presence of surgical intervention, pathological findings, culture positivity and microorganism, laboratory findings, scintigraphy, imaging modalities and outcome of disease.

Result

A total of 26 cases with malignant external otitis including 17 females (65.4%) and nine males (34.6%) patients were included in our study. Duration of symptoms before the initiation of treatment, and hyperbaric oxygen treatment did not positively influence the outcome. Inflammatory markers and Peleg staging significantly reflected the treatment response.

Conclusion

Close monitoring of inflammatory parameters is the key point in the prediction of prognosis. Planning the management and predicting the outcomes rely on proper radiological and clinical assessment of the extent of disease. In the assessment of MOE, universal scoring systems should be preferred for pooling the data in comparable manner.

Skull Base Fungal Osteomyelitis: A Case Report and Review of the Literature

Skull base osteomyelitis (SBO) is an invasive infection refractory to therapy, closely linked with malignant otitis externa (MOE). It is characterized by a mild clinical presentation that can delay cross-sectional imaging considered as the key to revealing it. Skull base osteomyelitis typically affects elderly diabetics and immunocompromised patients (>70 years). It most commonly has an otogenic origin due to an extension of MOE. The prognosis can be very poor without the administration of adequate and timely therapy at an early disease stage. Nowadays, Pseudomonas aeruginosa remains the most common pathogen associated with SBO. Fungi are a rare cause of MOE. This report documents a rare case of otogenic SBO caused by Candida parapsilosis in a diabetic patient, with persistent otologic symptoms as clinical onset and resistance to medical treatment. Fungal MOE has more subtle symptoms and is more aggressive than its bacterial counterpart. When MOE is resistant to antibacterial drugs, this should raise the suspicion of a fungal etiology of MOE. The current guidelines do not exhaustively describe the diagnosis, antifungal drugs of choice, and optimum duration of treatment. The description of these rare clinical cases should help with the multidisciplinary management of this disease in order to optimize the diagnosis and therapeutic protocol.