Differential diagnosis and treatments of necrotizing otitis externa: a report of 19 cases

Role of surgery along with antimicrobials in refractory skull base osteomyelitis-A prospective observational study

INTRODUCTION

Study aimed to ole of surgery along with antimicrobials to improve clinical outcomes in treating refractory cases of skull base osteomyelitis (SBO).

METHODS

A prospective observational study in a tertiary care centre with 70 SBO patients meeting eligibility criteria. The study population comprised 35 patients refractory to systemic antimicrobials of at least 4 weeks duration who later underwent surgery in addition to medication (surgical group). They were compared with a medical group that responded to medications alone. The outcome variables studied were the resolution of clinical features (pain, discharge, radiology, and inflammatory markers), culture yield, and total duration of treatment.

RESULTS

According to our study, relief of pain was faster in the surgical group (1.66 against 4.57 months) with statistical significance (p < 0.001). Relief of symptoms (p < 0.001), radiological improvement (p = 0.001), and normalising of inflammatory markers (p < 0.001) were better in the surgical group than in the medical group. The duration of treatment was an average of 9.2 months in the surgical group compared to 11.3 months in the medical group (p = 0.019). Microbial culture from deep tissue sampling was positive in 24 surgical patients (68.57%).

CONCLUSIONS

The treatment response in selected patients of refractory SBO who underwent surgery along with antimicrobials was better than the group who responded to antimicrobials alone. Surgery provided higher microbial yield resulting in culture-specific antimicrobials. The surgical group observed faster relief of symptoms, reduced hospital stay, and total treatment duration.

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.

The Association Between Malignant Otitis Externa and Diabetes Mellitus in Africa: A Systematic Review

Diabetes mellitus is one of the risk factors for malignant otitis externa. There are very few studies on the disease in Africa and there is a need to pool the prior studies to highlight the characteristics of the disease. The study type is a systematic review and the PRISMA guidelines were followed. Using the appropriate terms, relevant medical databases were systematically searched. Thirty-two studies met the eligibility criteria with a total sample size of 848, who were mainly elderly. Diabetes mellitus was present in 94% of the participants. Average duration of diabetes diagnosis in the participants was 12.4 years. The pooled HbA1c was 9.8%. The most common symptoms were otalgia (96.1%), otorrhoea (75.8%) and hearing loss (56.1%). Pseudomonas was the most common isolate (72%). Fluoroquinolones and the 3rd-generation cephalosporins were the preferred antibiotics. The pooled cure rate from antimicrobial usage was 76.2%. In addition to medications, 24.6% of the affected individuals required debridement. About 1.6% of the participants died from malignant otitis externa. Malignant otitis externa is associated with poorly controlled diabetes. Pseudomonas is the most common cause and a significant proportion gets cured with prolonged antibiotherapy.

Systematic review of the diagnosis and management of necrotising otitis externa: Highlighting the need for high-quality research

OBJECTIVES

To present a systematic review and critical analysis of clinical studies for necrotising otitis externa (NOE), with the aim of informing best practice for diagnosis and management.

DESIGN

Medline, Embase, Cochrane Library and Web of Science were searched from database inception until 30 April 2021 for all clinical articles on NOE. The review was registered on PROSPERO (ID: CRD42020128957) and conducted in accordance with PRISMA guidelines.

RESULTS

Seventy articles, including 2274 patients were included in the final synthesis. Seventy-three percent were retrospective case series; the remainder were of low methodological quality. Case definitions varied widely. Median patient age was 69.2 years; 68% were male, 84% had diabetes and 10% had no reported immunosuppressive risk factor. Otalgia was almost universal (96%), with granulation (69%) and oedema (76%) the commonest signs reported. Pseudomonas aeruginosa was isolated in 62%, but a range of bacterial and fungal pathogens were reported and 14% grew no organism. Optimal imaging modality for diagnosis or follow-up was unclear. Median antimicrobial therapy duration was 7.2 weeks, with no definitive evidence for optimal regimens. Twenty-one percent had surgery with widely variable timing, indication, or procedure. One-year disease-specific mortality was 2%; treatment failure and relapse rates were 22% and 7%, respectively.

CONCLUSION

There is a lack of robust, high-quality data to support best practice for diagnosis and management for this neglected condition. A minimum set of reporting requirements is proposed for future studies. A consensus case definition is urgently needed to facilitate high-quality research.

Clinical and Current Microbiological Profile with Changing Antibiotic Sensitivity in Malignant Otitis Externa

Malignant otitis externa (MOE) is a rare and fatal condition affecting temporal bone. It is also known as skull base osteomyelitis and is a rapidly progressive condition. This retrospective study evaluates the clinical, haematological, microbiological profile and management of malignant otitis externa in a tertiary care hospital and literature review. A retrospective review of 79 patients diagnosed with Malignant Otitis Externa from January 2015 to June 2021 was analyzed. History and Clinical findings, Imaging, Bacteriology, Random blood sugar on admission, Erythrocyte Sedimentation rate, HbA1C level, Biopsy of the granulation tissue from Externa auditory canal, cranial nerve involvement, duration of hospital stay, and treatment outcomes were analyzed. Out of 79 patients, otorrhea, otalgia, EAC oedema, and granulation were the most common findings. Facial nerve paralysis was found in 20 patients (25.3%) and multiple cranial nerve paralysis in 5 patients (6.3%). Uncontrolled diabetes mellitus and older age have increased duration of hospital stay, while cranial nerve paralysis did not affect this duration. Six different microorganisms were isolated. Pseudomonas aeruginosa was the most common organism cultured. Ciprofloxacin resistance was detected in 79% of cases. Amikacin, Cefaperazone-Sulbactam, and Piperacillin were the most sensitive antibiotics for gram negative organisms in our study. This study reviews the current microbiological profile and shows the need for higher-end antibiotics to treat MOE in present times. Early diagnosis, aggressive control of diabetes mellitus, and long duration culture-sensitive antibiotic therapy with regular monitoring are essential to reducing morbidity and mortality due to MOE.

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.

Necrotizing Otitis Externa: A Systematic Review and Analysis of Changing Trends

OBJECTIVE

To assess for changes in trends of the disease process, management, and outcomes of necrotizing otitis externa (NOE) over the last decade.

DATA SOURCES

Articles in English, published between January 2011 and June 2019, were searched in PubMed, Scopus, Web of Science, ScienceDirect, and the Cochrane Database.

STUDY SELECTION

Inclusion criteria: 1) reported evidence of NOE, 2) details on patient demographic and underlying medical disorder, 3) details on treatments, 4) documented outcomes, and 5) greater than 10 cases.

DATA EXTRACTION

Study demographics, underlying conditions, infectious etiology, treatments, signs and symptoms, and outcomes.

DATA SYNTHESIS

Ten studies, totalling 284 patients with a mean age of 67.8 years, were included. The time period of collected patient data ranged from 2000 to 2018. Temporal subgroup analysis was conducted before and after 2009. Cure rate was lower in the post-2009 group (76.0 versus 94.1%, p < 0.01) while disease-specific mortality remained stable. Increases in proportions of diabetes and culture negative results (p < 0.01) were also observed in this latter group. Rate of extensive surgery and the use of ciprofloxacin decreased (p < 0.01), while the use of ceftazidime increased in the post-2009 group (p < 0.01).

CONCLUSION

A decrease in cure rate of NOE patients was observed in the setting of an increase in prevalence of diabetes. Various antipseudomonal agents are being used and an increase in culture negative results is seen.

Agricultural systems as potential sources of emerging human mycoses caused by Trichoderma: a successful, common phylotype of Trichoderma longibrachiatum in the frontline

Trichoderma species are abundant in different agricultural habitats, but some representatives of this genus, mainly clade Longibrachiatum members are also emerging as causative agents of various human diseases with even fatal outcome. Strains of these species frequently show resistance to commonly used azole antifungals. Based on previous data it is hypothesized that Trichoderma isolates identified in human infections derive from environmental-including agricultural-origins. We examined Trichoderma longibrachiatum Rifai and Trichoderma bissettii Sandoval-Denis & Guarro strains recovered from four novel cases of human mycoses, along with isolates from previous case reports and different agricultural habitats, using multilocus phylogenetic analysis, BIOLOG Phenotype Microarrays and Etest. Strains attributed to T. bissettii were more abundant in both clinical and agricultural specimens compared to T. longibrachiatum. The majority of the isolates of both taxa could tolerate >256, >32 and >32 μg/ml fluconazole, itraconazole and posaconazole, respectively. None of the obtained results revealed characteristic differences between strains of clinical and agricultural origin, nor between the two taxa, supporting that agricultural environments may be significant sources of infections caused by these emerging human fungal pathogens. Furthermore, based on our findings we propose the re-classification of T. bissettii as T. longibrachiatum f. sp. bissettii.

Malignant Otitis Externa is Associated with Diabetes: A Population-Based Case-Control Study

Objective:

Despite studies reporting a possible association between malignant otitis externa (MOE) and diabetes, there are no large-scale population-based empirical studies. This nationwide, population-based case-control study explored the association of MOE occurrence with previously diagnosed diabetes.

Methods:

Data were retrieved from Taiwan’s National Health Insurance Research Database, 753 patients with MOE (cases) and 2 259 propensity score-matched patients without MOE (controls). Multiple logistic regressions were conducted to examine the association of MOE with previously diagnosed diabetes.

Results:

In total, 728 (24.2%) out of 3 012 sample patients had diabetes prior to the index date. Chi-square test revealed a significant difference in diabetes prevalence among cases and controls (54.8% vs 13.9%, p < 0.001). Simple logistic regression showed the odds ratio for prior diabetes among cases versus controls was 7.50 (95% CI, 6.22~9.03). The adjusted odds ratio of prior diabetes for cases versus controls was 10.07 (95% CI, 8.15~12.44) after adjusting for patient demographics and medical co-morbidities.

Conclusions:

This study found an association between MOE and diabetes. One clinical practice implication of our study is that when a patient with diabetes complains of otalgia or otorrhea, and physical examination shows swelling of the ear canal or granulation growth, physicians should consider the possibility of MOE.

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.

Sub-clinical middle ear malfunctions in elderly patients; prevalence, pattern and predictors

Background

Little is known about functioning of the middle ear with advancing age.

Objectives

To estimate the prevalence and describe tympanometric patterns of sub-clinical middle ear malfunctions,( S-MEM) in elderly patients. It also assessed clinical factors that could predict S-MEM.

Methods

Cross-sectional, analytical study of patients aged ≥ 60 years in a tertiary hospital in Nigeria between 2011–2014. Pure tone audiometry (PTA), tympanometry and acoustic reflexes were recorded. S-MEM was based on audiometric and tympanometric evident abnormalities. Descriptive, univariate and multivariate analyses performed to detect independent clinical predictors of S-MEM at p-value of <0.05.

Results

121 patients , M: F of 1.1:1. Mean age was 70.1 ± 6.2 years, 77.7% were married. Prevalence of S-MEM was 21.5%. Abnormal tympanometric tracings were type A_S>C>B>A_D. The parameters that were statistically-significant on univariate analyses were subjected to logistic regression analysis which confirmed previous head injury, diabetes, osteoarthritis of knee joint, and absent acoustic reflex as clinical predictors for S-MEM.

Conclusion

21.5% of elderly Africans had subclinical abnormalities in their middle ear functioning, mostly with type AS tympanogram. Independent clinical predictors of S-MEM included previous head injury, diabetes, history of osteoarthritis of knee joints, and absent acoustic reflex.

Current management of necrotising otitis externa in the UK: survey of 221 UK otolaryngologists

INTRODUCTION

Necrotising otitis externa (NOE) is a rare infection causing skull base osteomyelitis. The evidence regarding NOE consists mostly of case series. Hence, there is a limited evidence base to guide decision-making. This survey aims to report the experience of 221 otolaryngologists in this condition.

MATERIALS AND METHODS

Internet survey administered to the membership of the British Association of Otorhinolaryngology - Head and Neck Surgery (ENT UK).

RESULTS

Respondents' detailed replies on diagnosis, treatment and follow up are presented. One third of respondents reported increasing incidence of NOE. Over 80% diagnosed NOE based on pre-existing risk factors, severe pain, non-resolution of infection and CT scan. Most respondents managed NOE with intravenous antibiotics (90%) and blood sugar control (82%). There was less agreement in certain aspects of management including the role of surgery and the nature and duration of follow up.

CONCLUSIONS

Our survey provides a picture of NOE management in the UK. While there is consensus in some aspects of NOE management, other aspects attract widely differing answers. This may reflect the lack of strong evidence in the literature. Future work should aim to address this.

A Treatment Protocol for Management of Bacterial and Fungal Malignant External Otitis: A Large Cohort in Tehran, Iran

AIMS

High rates of negative microbiologic test results highlight the potential role of empiric antimicrobial agents in management of malignant otitis externa (MOE). This study investigates the clinical presentation, laboratory findings, and response to empiric treatment in a large group of patients admitted to a tertiary academic hospital in Tehran, Iran.

METHODS AND MATERIALS

We recruited 224 patients diagnosed with MOE in a prospective observation from 2009 through 2015. All patients received a 2-agent antibacterial regimen at baseline (phase I). Patients with no improvement within 10 days and/or nonresponders to a second course of antibacterials were switched to antifungals (phase II). Response to treatment was observed and documented in both groups.

RESULTS

All patients had physical symptoms for more than 12 weeks before admission. In total, 127 patients responded well to antibacterials. Eighty-seven out of 97 patients who were switched to antifungals had complete response to treatment; patients in the latter group had significantly higher A1C levels at baseline.

CONCLUSION

Our findings provide evidence to develop clinical guidelines that accelerate diagnosis and treatment of MOE to improve patient outcomes.

Clinical outcome parameters for necrotizing otitis externa

OBJECTIVE

To investigate the duration of time elapsed between the onset of symptoms for necrotizing external otitis (NEO) and admission to hospital that may play a role in patient outcome.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Fourteen consecutive male patients with NEO with no improvement from the previous course of antibiotherapy and with findings of osteomyelitis on temporal bone CT, MRI, and positive detection of Tc-99m methylene diphosphonate on temporal bone, admitted as inpatients between 2008 and 2012.

INTERVENTION(S)

Medical treatment of NEO and surgical debridement.

MAIN OUTCOME MEASURE(S)

Patients were divided into 2 groups according to median time elapsed between onset of symptoms and hospitalization (<30 d or >30 d). HbA1c, fasting blood sugar, erythrocyte sedimentation rate, C-reactive protein, pain intensity, radiologic grade, improvement since diagnosis, and total time to cure were compared according to the groups. The relationships between the laboratory data were analyzed to determine the parameters associated with time to recovery.

RESULTS

Otalgia was significantly worse in patients who were admitted to hospital greater than 30 days after symptom onset (Mann-Whitney U test, p < 0.002). Blood glucose increased related to delayed admission time (p < 0.001). CRP results were independently elevated from the admission time (p < 0.112). There was a statistically significant difference between groups according to ESR levels and recovery time (Mann-Whitney U test, p < 0.004 and p < 0.01). There was a positive correlation between HbA1c levels and recovery time in Group 1 and between ESR levels and recovery time in Group 2 (r = 0.872, p = 0.044; r = 0.630, p = 0.039).

CONCLUSION

Clinical, laboratory, and outcome data worsen later than 30 days in NEO.

Necrotizing otitis externa: a systematic review

OBJECTIVE

To carry out a systematic review of scientific evidence available about necrotizing otitis externa, emphasizing epidemiologic data, diagnosis criteria, treatment protocols, follow-up criteria, prognosis factors, and chronologic evolution.

DATA SOURCES

PubMed/MEDLINE and the Cochrane Database of Systematic Reviews were searched for publications in English and French languages, between 1968 and October 1, 2011.

STUDY SELECTION

We included publications of all types including at least 6 cases. We excluded publications focused on cranial base osteomyelitis not originating from the external ear and publications limited to a specific population.

DATA EXTRACTION

We assessed publication quality according to international guidelines.

DATA SYNTHESIS

For each publication, data were entered in a spreadsheet software for analysis. We excluded individual data already published in other studies or reviews.

CONCLUSION

Our review revealed the absence of strong scientific evidence regarding diagnosis criteria, treatment protocols and follow-up criteria. This implies the use of highly empirical indexes of suspicion in clinical practice. Our review confirmed the existence of a typical but not exclusive population at risk (aged, male, and diabetic patient) and also revealed major issues: lack of primary prevention in population at risk, delays before referral and management, bacteriologic issues caused by antibiotic misuse (agent identification problems, rise of resistant strains), persistence of recurrent cases. A better diffusion of medical information should help improve the management of this severe disease.

Antibiotic therapy in necrotising external otitis: case series of 32 patients and review of the literature

Necrotising external otitis (NEO) is a rare but severe bone infection, usually due to Pseudomonas aeruginosa, the management of which is not standardised. Systemic antibiotic therapy is usually prescribed for at least 6 weeks, but no review has been published on this topic. We report our experience and have reviewed the literature regarding antibiotic therapy in NEO. Here we describe a case-series of consecutive NEO cases seen over an 8-year period (2004-2011) in a French tertiary-care teaching hospital. Since 2009 we have shortened the duration of antibiotic therapy to 6 weeks. We also present a review of the literature regarding antibiotic therapy in NEO. We include 32 NEO cases, with positive microbiological cultures in 30 cases. Among the 30 patients with suspected or proven P. aeruginosa infections, 27 received an initial combination therapy of ceftazidime and ciprofloxacin. The duration of antibiotic therapy and length of hospital stay were significantly reduced after 2009 (9.4 ± 3.2 weeks versus 5.8 ± 0.7, P < .0.001; and 18.2 ± 8.7 days versus 11.6 ± 6.9, P = .0.03, respectively). Patient outcomes were favorable in all cases, with a 14-month median duration of follow-up. Our literature review (30 case series) shows that initial combination therapy is associated with better outcomes as compared with single therapy (97 % versus 83 %, P < .0.001). We suggest 3 weeks of initial combination therapy (ceftazidime + ciprofloxacin, high doses) followed by 3 weeks single therapy with ciprofloxacin in susceptible P. aeruginosa NEO. A close collaboration between ear, nose and throat and infectious diseases specialists is needed.