Diagnosis and treatment of necrotising otitis externa and diabetic foot osteomyelitis - similarities and differences

The diagnostic conundrum in necrotizing otitis externa

Necrotizing otitis externa (NOE) is an aggressive and fast-evolving infection of the external auditory canal. Late diagnoses and untreated cases can lead to severe, even fatal consequences and so early diagnosis and treatment are paramount. NOE is a notoriously challenging diagnosis to make. It is therefore important to understand what diagnostic modalities are available and how otolaryngologists can use them to accurately treat such an aggressive disease. This review aims to evaluate the different diagnostic options available in NOE and discuss their advantages and limitations, thus, providing an up-to-date picture of the multimodal approach required in the diagnosis of this disease.

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.

Malignant External Otitis: What the Diabetes Specialist Should Know-A Narrative Review

AIMS

Malignant external otitis (MEO) is a special type of external otitis associated with extensive inflammation and osteomyelitis. It is believed to originate from the external auditory meatus and advance regionally to the soft tissues and the bone, eventually involving the skull base. Pseudomonas aeruginosa and diabetes mellitus are factors commonly involved in the pathogenesis of MEO. Although its treatment has changed considerably during the last decades, morbidity and mortality of the disease remain high. Our aim was to review basic aspects of MEO, a disease unknown until 1968, which attracts great interest among Ears, Nose and Throat (ENT), diabetes and infectious diseases specialists.

METHODS AND RESULTS

In this narrative review we mainly include relevant papers written in English or with an English abstract. We searched PubMed and Google Scholar, using the keywords malignant external otitis, malignant otitis externa, necrotizing external otitis, skull base osteomyelitis, diabetes mellitus and surgery up to July 2022. Some of the most recent articles, with specific references to earlier articles and a book reference regarding the pathophysiology, diagnosis and treatment of MEO and its relationship to diabetes mellitus, were included.

CONCLUSION

MEO is not an uncommon disease and is principally treated by ENT surgeons. Nevertheless, diabetes specialists should be aware of the disease presentation and management, since they will often encounter patients with undiagnosed MEO or will need to manage glucose levels in patients hospitalized with the disease.

Malignant Otitis Externa: Diagnostic Dilemma in a Patient with Atypical Presentation

Malignant otitis externa (MOE) is a relatively rare complication of Otitis externa with a tendency to spread to other parts of temporal bone and skull base. Pseudomonas aeruginosa is the most common pathological agent. It generally occurs in the elderly with poorly controlled diabetes. In this report we present a case of MOE with atypical initial presentation causing immense conundrum in deciphering the diagnosis early.

Characteristics, management and outcome of a large necrotising otitis externa case series: need for standardised case definition

Background

Necrotising otitis externa is a severe ear infection for which there are no established diagnostic or treatment guidelines.

Method

This study described clinical characteristics, management and outcomes for patients managed as necrotising otitis externa cases at a UK tertiary referral centre.

Results

A total of 58 (63 per cent) patients were classified as definite necrotising otitis externa cases, 31 (34 per cent) as probable cases and 3 (3 per cent) as possible cases. Median duration of intravenous and oral antimicrobial therapy was 6.0 weeks (0.49–44.9 weeks). Six per cent of patients relapsed a median of 16.4 weeks (interquartile range, 23–121) after stopping antimicrobials. Twenty-eight per cent of cases had complex disease. These patients were older (p = 0.042), had a longer duration of symptoms prior to imaging (p < 0.0001) and higher C-reactive protein at diagnosis (p = 0.005). Despite longer courses of intravenous antimicrobials (23 vs 14 days; p = 0.032), complex cases were more likely to relapse (p = 0.016).

Conclusion

A standardised case-definition of necrotising otitis externa is needed to optimise diagnosis, management and research.

Diabetes and glycemic control in necrotizing otitis externa (NOE)

PURPOSE

Although the association between necrotizing otitis externa (NOE) and diabetes mellitus (DM) is well known, there is little knowledge in regards to the effects of DM and glycemic control on the outcome of NOE. The aim of the study was to determine the effects of DM duration and glycemic control, and in-hospital glycemic control on NOE severity.

METHODS

A retrospective case series analysis, including all patients hospitalized between 1990 and 2018 due to NOE were included. Data collected included NOE disease characteristics, duration of DM, DM-associated comorbidities, glycated hemoglobin (HbA1c), urine microalbumin and in-hospital blood glucose measurements. Disease severity was defined based on duration of hospitalization (above or below 20 days) and need for surgery.

RESULTS

Eighty-nine patients were included in the study. Eighty-three patients (94.3%) had DM. Preadmission HbA1c was 8.13% (5.8-12.6%). Forty-nine patients (65.5%) had mean blood glucose of ≥ 140 mg/dL and 26 (34.5%) had ≤ 140 mg/dL. DM duration was 157.88 months among NOE patients who required surgery, and 127.6 months among patients who were treated conservatively (p value 0.25). HbA1c in patients hospitalized < 20 days was 7.6%, and 8.7% among NOE hospitalized ≥ 20 days (p value 0.027). Seven patients with mean blood glucose of ≤ 140 mg/dL had Pseudomonas Aeruginosa (PA-NOE) (26.7%), in comparison to 25 (51.0%) with mean blood glucose measurement of ≥ 140 mg/dL (p = 0.045).

CONCLUSIONS

HbA1c at admission is associated with longer hospitalization duration among NOE patients. Mean blood glucose during hospitalization was associated with a higher likelihood of PA infection, however, it had no effect on disease outcome.

Malignant otitis externa: An updated review

Malignant otitis externa is a progressive infection of the external auditory canal and skull base. Pseudomonas aeruginosa is the most isolated microorganism and it affects mostly to diabetic, elderly, and immunocompromised individuals. Non-resolving otalgia and chronic otorrhea are the clinical manifestations presented. Facial nerve palsy is a common and well recognized complication. (Computed tomography) CT scan is useful for initial assessment, Technetium-99m is highly sensitive and is part of the protocol for diagnosis. Treatment should be individualized, with multidisciplinary cooperation among specialties. Management involves systemic antipseudomonal antibiotics and monitoring with radiologic techniques, it also involves the strict control of diabetes. It is essential to follow up the patients for at least a year post-treatment. In refractory malignant otitis externa and affection of facial nerve, surgical management is recommended. We reviewed the most recent studies on epidemiology, clinical manifestations, diagnosis, and treatment to provide an update on Malignant Otitis Externa that can offer an overview for clinical practice and future research.

The application of ceragenins to orthopedic surgery and medicine

Osteomyelitis and infections associated with orthopedic implants represent a significant burden of disease worldwide. Ceragenins (CSAs) are a relatively new class of small-molecule antimicrobials that target a broad range of Gram-positive and Gram-negative bacteria as well as fungi, viruses, and parasites. This review sets the context of the need for new antimicrobial strategies by cataloging the common pathogens associated with orthopedic infection and highlighting the increasing challenges of managing antibiotic-resistant bacterial strains. It then comparatively describes the antimicrobial properties of CSAs with a focus on the CSA-13 family. More recently developed members of this family such as CSA-90 and CSA-131 may have a particular advantage in an orthopedic setting as they possess secondary pro-osteogenic properties. In this context, we consider several new preclinical studies that demonstrate the utility of CSAs in orthopedic models. Emerging evidence suggests that CSAs are effective against antibiotic-resistant Staphylococcus aureus strains and can prevent the formation of biofilms. There remains considerable scope for developing CSA-based treatments, either as coatings for orthopedic implants or as local or systemic antibiotics to prevent bone infection.

Necrotising otitis externa: A single centre experience

Introduction

Necrotising otitis externa (NOE) is a rare infection of the ear canal with frequent bone erosion. This study’s objective is to describe the different features of NOE as well as its management in an ear-nose-throat department. We also tried to identify the particularities of the fungal infection.

Patients and methods

It is an observational cohort that included all the patients hospitalised for the management of NOE. The study was carried out in the ear-nose-throat Department of Mahdia University Hospital in Tunisia between January 2006 and december 2019.

Results

A total of 40 patients were included. The mean age was 65 ± 12.9 years and the sex ratio was 0.9. Ninety percent of the patients included were diabetics. The most common signs found were oedema of the external canal (97.5%) and auricular discharge (92.5%). The main pathogen isolated was Pseudomonas aeruginosa (61.7%). Fungi were isolated in 9 cases (26.47%). Computed tomography was performed for 32 patients (80%). Bone erosion was seen in 26 cases (81.3%). The main complications were cerebral venous thrombosis, retropharyngeal abscess and cerebral empyema. Thirty one patients received only antibiotics, 2 received only antifungal treatment, and 7 received both antibiotics and antifungal treatment. All patients had a favorable outcome. Univariate analysis showed a higher median erythrocyte sedimentation rate was associated with fungal infections. No other differences were noted.

Conclusion

Our management protocol seems to be efficient since all patients had initial favorable outcome. A higher median erythrocyte sedimentation rate was associated with fungal infections.

•

Necrotising otitis externa has a variable clinical presentation and a relatively high rate of complications.

•

The patients were mainly diabetics or aged more than 65 years old.

•

The main pathogen isolated was Pseudomonas aeruginosa.

•

A higher median erythrocyte sedimentation rate was associated with fungal infections.

Prediction of skull base osteomyelitis in necrotising otitis externa with diffusion-weighted imaging

OBJECTIVE

To predict skull base osteomyelitis in patients with necrotising otitis externa using diffusion-weighted imaging.

METHODS

A retrospective analysis was conducted of 25 necrotising otitis externa patients with skull base osteomyelitis (n = 10) or without skull base involvement (n = 14) who underwent a single-shot diffusion-weighted imaging of the skull base.

RESULTS

The respective mean apparent diffusion coefficient values of the skull base, as determined by two reviewers, were 0.851 ± 0.15 and 0.841 ± 0.14 ×10-3mm2/s for the skull base osteomyelitis patients, and 1.065 ± 0.19 and 1.045 ± 0.20 ×10-3mm2/s for the necrotising otitis externa patients without skull base involvement. The difference in apparent diffusion coefficients between the groups was significant, for both reviewers (p = 0.008 and 0.012). The optimal threshold apparent diffusion coefficient for predicting skull base osteomyelitis in necrotising otitis externa patients was 0.945 ×10-3mm2/s and 0.915 ×10-3mm2/s, with an area under the curve of 0.825 and 0.800, accuracy of 87.5 and 83.3 per cent, sensitivity of 85.7 and 90.0 per cent, and specificity of 90.0 and 78.6 per cent, for each reviewer respectively.

CONCLUSION

Apparent diffusion coefficient is a non-invasive imaging parameter useful for predicting skull base osteomyelitis in necrotising otitis externa patients.

Malignant Otitis Externa: Causes for Various Treatment Responses

OBJECTIVES

Malignant (necrotizing) otitis externa (MOE) is an aggressive form of skin inflammation of the external ear with a tendency to spread infection to the temporal bone. The study aimed to evaluate a causal relationship between treatment responses and clinical features in patients with MOE.

MATERIALS AND METHODS

In a retrospective, descriptive section study, the database was analyzed between January 2008 and December 2018 in our department, all patients with diagnosed MOE were identified.

RESULTS

A total of 30 patients were evaluated, of which 27 men and 3 women. The youngest patient was 52 years old while he was eldest 88 years, (mean-71 years old). As the most common comorbidity, diabetes mellitus was found in 23 (76%) subjects. Median duration of symptoms was about 3 months. The most common isolated pathogen was Pseudomonas aeruginosa (47%). Patients with facial nerve palsy and erosion of temporal bone find on computerized tomography affect prolonged stationary treatment (Mean, SD 29.2±8.5 and 26,7±11.6 days), while 80% of patients with facial nerve palsy had recurrence of disease (p=0.005) with mean duration of clinical remission of 60±17.3 days. Overall length of treatment is also increased in the presence of comorbidities as well as in patients with cranial nerve involvement.

CONCLUSION

Patients with cranial nerve involvement, erosion of temporal bone and presence of comorbidities affect prolonged treatment and adverse prognosis. Early diagnosis and initiation of aggressive therapy are essential for stopping the further spread of the disease and prevention of serious complications.

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.

Evidence mapping of recommendations on diagnosis and therapeutic strategies for diabetes foot: an international review of 22 guidelines

To systematically review clinical practice guidelines (CPGs) on diabetes foot and assess the consistency of recommendations, quality of CPGs and to present an evidence-map for explicating research trends and gaps. We performed a literature search on PubMed, Embase, and Web of Science, guideline databases and websites of diabetes society to include the diabetic CPGs. The basic information, recommendations for the diabetic foot, methodological quality and reporting quality of diabetic CPGs were exacted by the Excel. Four researchers evaluated the methodological and reporting quality of diabetic foot CPGs by AGREE II instrument and RIGHT checklist. R3.5.1 software was used to create all bubble plots. A total of 22 diabetic CPGs were included, eight CPGs were from different professional diabetes societies. Recommendations on diabetic foot complications involve Diabetic foot ulcer (DFU), Charcot neuropathy (CN) and Osteomyelitis (OM). Eight DFU diagnostic systems presented in 22 CPGs. According to the recommendations of diabetic CPGs, the treatment of DFU can be summarized in four major items; six recommendations on CN diagnosis and six recommendations on treatment of CN were consistent among studies. However, there were inconsistencies in three OM diagnosis recommendations and four OM treatment recommendations. Some recommendations in CPGs were not very specific and clear, and hence they were not reliable for OM diagnosis and treatment. Once these inconsistencies are resolved, validated, accurate and effective diagnosis and treatment of diabetes foot will lead to reduced costs and adverse complications. The results of this review add to our knowledge and promote the development of trustworthy CPGs on diabetes.

Malignant otitis externa in a 21-year-old male patient with Prader-Willi syndrome

Malignant otitis externa is an invasive infection of the external auditory canal and temporal bone with potentially life-threatening complications. Elderly patients with type 2 diabetes mellitus are the population most commonly affected by malignant otitis externa, but any type of immunosuppression predisposes to the disease. Prader–Willi syndrome is a genetic cause of obesity, often associated with insulin resistance and type 2 diabetes mellitus. This report describes a case of a 21-year-old male patient with Prader–Willi syndrome who had malignant otitis externa that progressed to sepsis during hospitalization. To the best of the authors’ knowledge, this is the first description of malignant otitis externa in a young patient with Prader–Willi syndrome.