Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS).

The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting.

The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.

Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research.

The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

Necrotising otitis externa is a serious infection with minimal evidence underpinning its management. This review aims to synthesise published evidence of antimicrobial therapies and their outcomes in necrotising otitis externa.

The review was PROSPERO registered (CRD42022353244) and conducted according to Preferred Reporting Items for Systematic Review and Meta-Analyses (‘PRISMA’) guidelines. A robust search strategy filtered 28 manuscripts into the final review. Antimicrobial therapy and clinical outcome data were extracted and analysed.

Published studies are heterogeneous, with high risk of bias and low certainty. Reporting of outcomes is poor and extremely variable. First-line therapy is most commonly in-patient (95 per cent) empiric fluoroquinolone (68 per cent) delivered intravenously (82 per cent). The lack of granular data and poor outcome reporting mean it is impossible to correlate treatment strategies with clinical outcomes.

Robust, consistent outcome reporting with reference to treatments administered is mandatory, to inform clinical management and optimise future research. Optimal antimicrobial choices and treatment strategies require clarification through prospective clinical trials.

Osteomyelitis of the frontal bone is a rare but devastating complication of frontal sinusitis. Treatment involves aggressive surgery to remove all sequestra in combination with long-term antibiotic therapy. However, systemic antibiotics may struggle to penetrate any remaining infection in devascularised areas, and the morbidity associated with surgical resection of some areas of the skull base is too high. In contrast, locally implanted antibiotics provide a reliable, high concentration of treatment to these areas while also minimising potential systemic side effects. The clinical application of tobramycin beads has primarily been used in orthopaedics as an adjunct to the treatment of tibial osteomyelitis or prosthetic joint infection.

To the best of the authors' knowledge, the two cases discussed here represent the first use of tobramycin antibiotic beads in frontal sinus osteomyelitis secondary to chronic rhinosinusitis.

These cases show promising use of tobramycin beads in recalcitrant frontal osteomyelitis.

A key clinical feature of necrotising otitis externa is granulation tissue arising from the ear canal, representing epidermal compromise. The aim of this work was to explore the role of epidermal compromise in the aetiology of necrotising otitis externa.

A structured risk factor history was taken from 54 patients diagnosed with necrotising otitis externa between 2017 and 2022. Primary care records were also reviewed.

A total of 94 per cent of patients reported incidents of potential epidermal compromise preceding severe pain onset, including a 35 per cent incidence of ear syringing. A total of 94 per cent of patients were immunosuppressed, including 78 per cent with diabetes. All patients had medical co-morbidities.

This study proposed an aetiological triad for necrotising otitis externa: immunosuppression, infection and epidermal compromise. Epidermal compromise is a potentially modifiable risk factor for necrotising otitis externa. Meticulous primary ear care for older adult, diabetic and immunosuppressed patients is recommended. These populations should never undergo ear syringing and should avoid ear canal trauma and prolonged exposure to moisture.

This paper reports a case series of three elderly patients who were regularly attending ENT clinic every four to six weeks for ear canal care to address chronic otitis externa. All three patients had been taking bisphosphonate alendronic acid for years, and it is suspected that this drug was partly to blame for the progression of their chronic ear conditions.

Some improvements were noted when the bisphosphonate was discontinued. The regular microsuctioning, and application of topical antibiotics with steroids, provided temporary relief of symptoms. The present pandemic shut down the routine clinic and the patients were not seen for four to five months. On latest review, it was a surprise to see that their ears seemed to have significantly improved, with healthy re-epithelialisation.

It is thus believed that excessive and repeated microsuctioning in bisphosphonate-induced osteonecrosis of that external ear canal can delay re-epithelialisation, and gradually prolonging the intervals between microsuctioning could help in overall resolution of the disease.

Necrotising otitis externa is a serious infective condition. Patients are typically frail, diagnostic delay is common and severe pain is a key feature. This study aimed to qualitatively analyse patient-centred data to identify key themes in the patient's experience.

Open-ended questionnaires were sent to 28 patients. Responses were qualitatively analysed using a grounded theory approach. Iterative cycles were used to develop codes using a constant comparison technique. Emerging categories were refined to identify core themes.

Four main themes emerged: severe pain, mental health, quality of life and diagnostic delays.

This is the first study to explore patients’ perspectives in necrotising otitis externa. It indicates a need to raise awareness of necrotising otitis externa, and to improve symptom management, pain control and quality of life. This valuable information can be used to identify research priorities, guide service improvements, improve clinical care and feed into the development of a Core Outcome Set for necrotising otitis externa.

Necrotising otitis externa is a severe, life-threatening infection. Epidemiological data demonstrate a dramatic rise in reported cases in England from 2002 to 2017. The reasons for this remain elusive.

A quantitative descriptive study was undertaken using epidemiological data from the Hospital Episode Statistics database. Cases from 2002 to 2017 were compiled and analysed. Four potential theories were explored to explain the rise in incidence.

Within the 16-year period, 7327 necrotising otitis externa cases were reported. Annual necrotising otitis externa incidence increased 1142 per cent within the 16-year period, from 123 recorded cases in 2002 to 1405 cases in 2017. This correlates with an increasing prevalence of diabetes, an ageing population and likely increased physician awareness of necrotising otitis externa. There is insufficient evidence to support antibiotic resistance as a significant associated factor.

Correlation does not imply causation. It is likely that a combination of factors is contributing to the rise in necrotising otitis externa incidence, including increased physician recognition, diagnosis and accurate clinical coding.

The increased incidence of necrotising otitis externa over the last decade has had a significant burden on healthcare providers. Several factors may affect outcome, and stratifying risk may allow personalised treatment.

Retrospectively identified patients were prospectively surveyed over 12 months. The Cox proportional hazards model was used to identify predictors of poor prognosis.

Twenty-six patients with necrotising otitis externa (average age of 80 years) were admitted from 2018 to 2019. At one year, 19 per cent mortality was observed. A high Charlson Comorbidity Index was associated with increased mortality (p = 0.03), prolonged in-patient stay (p = 0.047) and increased odds of adverse outcomes (odds ratio = 1.48, 95 per cent confidence interval = 0.26–2.67, p = 0.019). The Charlson Comorbidity Index in our prognostic model was validated using the receiver operating characteristic curve (area under the curve = 0.76). Charlson Comorbidity Index score of 5 or more independently predicted one-year morbidity and mortality (hazard ratio = 1.30, 95 per cent confidence interval = 0.94–1.79, p = 0.03).

Risk-stratifying patients may enable clinicians to holistically counsel patients and tailor their treatment to improve their prognosis and subsequently alleviate the burden of necrotising otitis externa.

Otitis externa accounts for 1.1–1.3 per cent of patient presentations in primary care and 25 per cent of urgent referrals to ENT. This study aimed to explore otitis externa clinical decision-making at the primary-secondary care interface, otitis externa prevalence and recent trends in antimicrobial resistance in otitis externa related bacterial isolates and ototopical prescribing.

This is a mixed-methods study drawing on data from primary and secondary care and open National Health Service sources.

A total of 101 general practitioner survey respondents reported frequently prescribing oral antibiotics for otitis externa. General practitioner consultations for otitis externa increased 25 per cent over 15 years. General practitioner ototopical preparations cost the National Health Service £7 410 440 in 2006 and £11 325 241 in 2016. A total of 162 consecutive hospital otitis externa-related bacterial isolates yielded 128 pseudomonas species, with 18 that were resistant to gentamicin and 7 that were resistant to ciprofloxacin. Ten guidelines reviewed showed systematic inconsistencies.

General practitioners reported regularly prescribing oral antibiotics for otitis externa. Antimicrobial drug resistance is common in otitis externa. The available guidance is suboptimal.

Necrotising otitis externa is a serious condition that requires hospital admission. Longer hospital stays are associated with increased complications.

This was a closed audit cycle in a tertiary ENT centre of patients presenting with necrotising otitis externa to the ENT department between 2015 and 2019. The aim was to audit the length of hospital stay in comparison to national figures as well as the time needed for investigations.

The number of patients with necrotising otitis externa is increasing in England. Length of stay, however, appears to be more stable. A total of 66 admissions occurred over the study period for 48 patients in total, and mean length of stay was 12.4 days. After implementation of a new protocol, length of stay was reduced to 7.1 days.

Patients with necrotising otitis externa require prompt diagnosis and management in order to shorten length of stay in hospital and avoid serious complications. Multi-disciplinary protocol development and implementation could help in reducing length of stay of necrotising otitis externa patients.

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.

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.

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.

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

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

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.

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.

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

Pott's puffy tumour is a rare complication of sinusitis. This osteomyelitis can affect the outer and inner tables of the frontal sinus. The treatment of Pott's puffy tumour combines medical and surgical approaches. Surgical approaches have traditionally been open, but endoscopic techniques have been adopted recently in select cases. The bony defect from debridement can be left alone, or closed with autografts or allografts.

To describe a technique for the reconstruction of a large skull vault after the debridement of extensive osteomyelitis of the anterior cranial vault.

Modified distraction osteogenesis is used in the cranial vault, to induce new bone formation. This is customarily used to lengthen long bones. The advantages of this technique include avoiding autologous grafts or alloplastic cranioplasty in the infected surgical bed, and allowing primary closure.

Early post-operative imaging results have been encouraging, with no reported complications.

Modified distraction osteogenesis is a novel technique in the primary reconstruction of calvarial bone.

Necrotising otitis externa is a severe inflammatory process affecting soft tissue and bone, mostly in diabetic patients. Diabetic patients are also at risk of diabetic foot osteomyelitis, another inflammatory condition involving soft tissue and bone. This review aimed to describe the similarities and differences of these entities in an attempt to further advance the management of necrotising otitis externa.

A PubMed search was conducted using the key words ‘otitis externa’, ‘necrotising otitis externa’, ‘malignant otitis externa’, ‘osteomyelitis’ and ‘diabetic foot’.

The similarities regarding patient population and pathophysiology between necrotising otitis externa and diabetic foot osteomyelitis raise basic questions concerning the effects of long-standing diabetes on the external ear. The concordance between local swabs and bone cultures in diabetic foot osteomyelitis is less than 50 per cent. If this holds true also to necrotising otitis externa, the role of deep tissue cultures should be strongly considered. Similar to diabetic foot osteomyelitis, magnetic resonance imaging should be considered in selected necrotising otitis externa subgroups.

Non-traumatic bone fractures in cancer patients are usually pathological fractures due to bone metastases. In head and neck cancer patients, clavicle stress fractures may occur as a result of atrophy of the trapezius muscle after neck dissection in which the accessory nerve becomes structurally or functionally damaged.

A 71-year-old man underwent modified radical neck dissection with accessory nerve preservation and post-operative radiotherapy for submandibular lymph node metastases of tongue cancer. Four weeks after the radiotherapy, a clavicle fracture, with osteomyelitis and abscess formation in the pectoralis major muscle, occurred. Unlike in simple stress fracture, long-term antibiotic administration and drainage surgery were required to suppress the inflammation.

As seen in the present patient, clavicle stress fractures may occur even after neck dissection in which the accessory nerve is preserved, and may be complicated by osteomyelitis and abscess formation owing to risk factors such as radiotherapy, tracheostomy and contiguous infection.

Central skull base osteomyelitis is clinically difficult to distinguish from malignancy.

The computed tomography and magnetic resonance imaging scans of six patients with central skull base osteomyelitis were compared with scans from patients with a range of skull base conditions.

Computed tomography scans of central skull base osteomyelitis show much less bony destruction relative to the magnetic resonance imaging changes, whereas malignancy cases were associated with similar bony destruction on computed tomography and magnetic resonance imaging. In magnetic resonance imaging scans, it was possible to confirm previous findings of clival hypointensity on T1-weighted images relative to normal fatty marrow. In addition, there were signs of pre- and para-clival soft tissue infiltration, with the obliteration of normal fat planes and frank soft tissue masses in all six central skull base osteomyelitis patients. Signal intensity on T2-weighted images of the clivus was high in five central skull base osteomyelitis patients. With intravenous contrast, fascial plane anatomy appeared restored in central skull base osteomyelitis cases, almost in keeping with that of non-involved areas. This was not a feature in any of the malignant conditions.

Necrotising (malignant) otitis externa is a severe infection causing temporal bone osteomyelitis. Although rare, our experience (reported herein) shows local doubling of cases in 2013. Hospital Episodes Statistics data for England over 14 years also indicate increased incidence nationally. Specific learning points in management are also discussed.

A retrospective review was conducted of patients admitted in 2013 to Wexham Park Hospital, Slough, UK (catchment population, 450 000). In addition, the UK Government Hospital Episodes Statistics data were interrogated.

There were five cases of necrotising (malignant) otitis externa in 2013, representing a local doubling on previous years. The mean age of patients was 82 years. All cultures grew Pseudomonas aeruginosa; no isolates were antibiotic resistant. All patients responded to systemic anti-pseudomonals on clinical, biochemical and radiological parameters. Hospital Episodes Statistics data showed a six-fold increase in the number of cases from 1999 (n = 67) to 2013 (n = 421).

Our experience suggests increasing necrotising (malignant) otitis externa incidence, and retrospective analysis of Hospital Episodes Statistics data supports this observation. Necrotising (malignant) otitis externa poses challenges in management, as exemplified in our cases, requiring a high index of suspicion and early aggressive treatment to achieve cure.

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.

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.

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.

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.