Malignant otitis external-our experience

Malignant external otitis is an extremly morbid ostomnyelits of external auditary canal, mastoid and skitil base caused by pseudomonas arergenosa. We report our experience with six cases, which we came across in ten years.Patitents’ profile our management and results are presented. A need for increasing awareness tif the condition and the probability uj early diagnosis with a high index of suspicion in the early stages is discussed. Attempt also is done to review a few recent articles with special emphasis on imaging techniques and radioistope scans.     

The use of trichloroacetic acid in the treatment of acute external otitis

The purpose of this study was to evaluate the effectiveness of 5% trichloroacetic acid (TCA) in the treatment of acute external otitis (AEO) in comparison with a standard clinical treatment. All patients who consecutively presented in our emergencies with AEO during the summer months of the previous year were included in the study. They were randomly divided into two groups: the study group included 117 patients treated with TCA and the control group included 98 patients treated with ear drops containing antibiotic and corticosteroid. Occasionally, an antibiotic was administered orally for 7 days, in severe cases of AEO. All patients were evaluated on days 1, 3, 5, 7 and 10, whereas another review appointment was given 20 days later. Outcome measures included evaluation of efficacy using a six-step infection score and tolerability by visual analogue scale. Additionally, adverse reactions, complications and recurrencies were recorded. Treatment was successful for all patients of the study group, whereas 8 failures were found in the control group. The infection score improved faster in the study group than in the control group, resulting in an earlier clinical cure (mean 4.1 and 8.6 days, respectively). Tolerability was significantly better in the study group, on all points of evaluation. Complications and adverse reactions were minimal on both groups. Our results show that TCA is a very effective and nontoxic agent for the treatment of AEO. Rapid pain relief and prevention of recurrencies are its main advantages.     

External ear resonance in children with otitis media with effusion

A middle ear effusion has been shown, in KEMAR, to increase the height of the resonant peak of the external auditory canal by 6 dB SPL. It has also been shown that the hearing impairment due to otitis media with effusion is related to the volume of middle ear fluid. Therefore, it was hypothesized that measurement of the height of the resonant peak of the external auditory canal could be used as a method of assessing the magnitude of any hearing impairment due to otitis media with effusion. 182 ears from 182 children aged 3–12 (mean 6.3) years were studied. Pure-tone audiometry and impedance tympanometry were performed, and the acoustics of the external auditory canal were measured using the Rastronics CCI-10 frequency response analyser. The mean height of the resonant peak (17.9 dB SPL) of children with a type A tympanogram was significantly different from the mean value (23.6 dB SPL) of those with a type B tympanogram. There was a significant correlation between the height of the resonant peak and the speech frequency average of the pure-tone thresholds. The sensitivity and specificity of using the height of the resonant peak to detect hearing impairments in different age groups were calculated and compared with the sensitivity and specificity of tympanometry. The test did not provide the same degree of sensitivity as tympanometry but was more specific. The additional advantages of the test are that it is quick, taking less than 1 min per ear, and is well tolerated by children in whom there was a 99% compliance. It is suggested that measurement of the height of the resonant peak of the external auditory canal holds potential as a quick and objective method of screening and monitoring the hearing impairment of children with otitis media with effusion.     

Skin prick test reactivity in patients with chronic eczematous external otitis

Objectives

To investigate the incidence of skin prick test (SPT) positivity in patients with eczematous external otitis.

Methods

Forty-six patients with eczematous external otitis and forty-four healthy volunteers were included in the study. All the patients were skin-tested by prick test. Reactions were assessed by the degree of redness and swelling and the size of the wheal produced.

Results

According to SPT positivity and total immunoglobulin E values, the difference between the study and the control groups was statistically significant (P<0.05). The most common skin reactions were against to mites and grasses in this study.

Conclusion

Eczematous external otitis is perhaps the most difficult to treat of all forms of external otitis because the provocative agents usually remain undiagnosed. Patients suffering from eczematous external otitis symptoms should be investigated for allergens and be informed for prevention of the causative agents. SPT might be performed in cases of prolonged or treatment-resistant external otitis.     

Malignant external otitis: treatment with prolonged usage of antibiotics and Burow's solution

Malignant external otitis is a severe infection of the external auditory canal, generally caused by Pseudomonas aeruginosa in elderly diabetics patients. We describe a case of malignant external otitis in a 63-year-old man with severe otalgia, purulent otorrhea and polypoid granulation of the external auditory canal. Local debridement, insulin treatment and 6-week intravenous antibiotic therapy with carbapemens were very effective and the granulation tissue disappeared completely. However, the patient readmitted for recurrent disease 3 weeks later, despite the oral and ear drop administration with new quinolone. No recurrence has been noted after 4-week additional treatment with intravenous carbapenems followed by 3-week treatment with Burow's solution as ear drops.     

Intra-arterial administration of antibiotics for refractory skull base osteomyelitis

We report two cases of elderly diabetic men with skull base osteomyelitis (SBO) originating from malignant external otitis (MEO). In both, a devastating infection and neural paralysis deteriorated after conventional therapy, including long-term intravenous administration of culture-directed antibiotics with strict control of blood sugar levels and surgical debridement of infectious granulation tissue. Since poor perfusion of antibiotics in the lesion may be associated with serious nature of MEO/SBO, we administered antibiotics intra-arterially via a retrograde catheter with the tip set at the proximal point of the external carotid artery to increase the tissue drug concentration in the maxillary artery (MA) and ascending pharyngeal artery (APA) supply areas, in which intense inflammation was observed. This intra-arterial administration of antibiotics (IA therapy) followed by long-term intravenous and oral antibiotic treatments eliminated their infection and no recurrence was observed in 2 years follow-up period. Interestingly, CT images of angiography via the catheter demonstrated stronger enhancement in the MA supply area compared to the APA supply area and IA therapy was more effective in the former. These results suggest that IA therapy, which might achieve high antibiotic concentration at the site of infection, is effective in patients with MEO/SBO refractory to conventional treatments.     

Usefulness of CT scans in malignant external otitis: effective tool for the diagnosis,but of limited value in predicting outcome

Computerized tomography (CT) scanning is a well recognised tool for the diagnosis of malignant external otitis. To investigate the degree of correlation between CT findings scan and the patients clinical status focusing on a subgroup of patients with cranial nerve palsies. Diagnosis of malignant external otitis was confirmed in 23 patients (average age 71 years, age range 39–87) based on criteria of severe pain, otitis externa refractory to conventional treatments and possibly diabetes mellitus and pseudomonas detection. CT was performed on 23 of these patients. Results from these scans were analysed and correlated with patient clinical status. Retrospective analysis of CT images and medical notes were used for data analysis.The CT scans of all 23 patients showed evidence of involvement of disease outside the external auditory canal, confirming the diagnosis. Sixteen out of 23 patients (70%) demonstrated evidence of bone erosion. Four of the 16 showed involvement of the petrous apex. From our subset of ten patients with cranial nerve involvement, eight demonstrated evidence of bone erosion and two showed mastoid and middle ear involvement without bone erosion. All four patients with petrous apical involvement presented with cranial nerve palsies (two lower cranial nerve palsies, one seventh nerve palsy and one combined lower and seventh nerve palsy). CT scanning was found to be a fast and economical tool in the initial assessment of patients with malignant external otitis. Petrous apex involvement was constantly associated with cranial nerve palsies, usually the lower cranial nerves. CT findings of temporal bone in itself however, were not closely correlated to the clinical outcome of the patients.     

Low‐cost dual‐action aural foreign‐body extractor

Adequate visualization, appropriate equipment, a cooperative patient, and a skilled physician are keys to successful foreign body removal. The first attempt at removal is critical because success rates markedly decrease after the first failed attempt. Laryngoscope, 119:351–354, 2009     

Cranial nerve involvement in malignant external otitis: implications for clinical outcome

BACKGROUND: Malignant external otitis is an uncommon, potentially lethal infection of the temporal bone primarily affecting elderly diabetic patients. OBJECTIVE: To determine whether cranial nerve involvement in malignant external otitis affects or predicts the clinical outcome in terms of morbidity and mortality. METHODS: Diagnosis of malignant external otitis was established in 23 patients (average age, 71 yr; range, 39-87) based on inclusion criteria of severe pain, otitis externa refractory to conventional treatments, diabetes mellitus, and Pseudomonas aeruginosa detection. Computed tomography confirmed temporal bone involvement extending outside the external auditory canal. DATA ANALYSIS: Retrospective analysis of hospital records. RESULTS: Ten of 23 (43.5%) patients showed cranial nerve involvement. The following cranial nerves were affected: facial nerve (6/10), lower cranial nerves (combination of IX, X, XI, XII) (3/10), and extended nerve palsy (VI, VII, IX, X, XI) (1/10). Thirteen of 23 (56.5%) patients displayed no cranial nerve involvement. All patients were treated with long-term, high-dose antibiotic treatment dependent on the microbiological findings. CONCLUSIONS: All patients with lower cranial nerve palsy recovered normal function; however, the facial nerve palsy was significantly less likely to improve by medical treatment. Cranial nerve involvement did not affect the patient survival rate under an optimized medical treatment in our series.     

Clinical and bacteriological studies in otitis externa in Dar es Salaam,Tanzania

The symptoms and signs as well as the bacterial flora from the auditory canals of 54 Tanzanian patients (74 ears) living in Dar es Salaam and suffering from otitis externa were studied. Itching and pain were the most common symptoms and erythema and secretion were the prevalent clinical findings. Pseudomonas aeruginosa was found in 38%, Aspergillus in 24%, Staphylococcus aureus in 18% and Candida albicans in 14%. Bacterial cultures from the auditory canals of 21 healthy subjects revealed only normal skin flora.     

Necrotizing external otitis: aminoglycoside and β-lactam antibiotic treatment combined with surgical treatment

Necrotizing external otitis is a life-threatening condition that still causes therapeutic problems. A retrospective analysis of 22 patients who were all treated with a short standard course of aminoglycoside and β-lactam antibiotic with thorough local debridement was carried out; 50% (11/22) had diabetes mellitus, and all had a positive culture of Pseudomonas aeruginosa. The frequency of recurrence was 14% (3/22), and 95% (21/22) were eventually cured. The treatment course lasted 17 days on average. Side effects caused by the drug treatment were seen in 14% (3/22), but they were mild and transient consisting of a reversible increase of the serum creatinine level. It was concluded that the treatment was short, efficient, safe, and as successful as treatment with quinolones or third-generation cephalosporins which has been reported during the past years. In our opinion, therefore, these drugs should be reserved for cases of treatment failure, development of resistance, or side effects.     

Necrotizing external otitis in a patient caused by Klebsiella pneumoniae

Necrotizing external otitis is a potentially life-threatening infection involving the temporal and adjacent bones. The most frequent pathogen is attributed to Pseudomonas aeruginosa, but is rarely caused by Klebsiella pneumoniae. Recently, we encountered a 47-year-old diabetic man with a swollen obliterated external ear canal with granulation tissue on the right ear. Image study demonstrated skull base osteomyelitis, epidural abscess and cerebral venous sinus thrombi. It was later proved to be necrotizing external otitis caused by Klebsiella pneumoniae. He then underwent craniotomy for drainage of the epidural abscess, followed by intravenous ciprofloxacin and metronidazole for 2 consecutive weeks until both pus and blood cultures depicted no growth of pathogens. Based on this case, synergistic antibiotic therapy using a third-generation cephalosporin or quinolone (ciprofloxacin), accompanied by metronidazole, and even a short-term aminoglycoside is recommended for the treatment of severe Klebsiella-induced necrotizing external otitis. Surgical intervention should be limited without shedding of the pathogens.     

Microbiology of Acute Otitis Externa

Objective To isolate and characterize bacteria and fungi from acute otitis externa (AOE) and to obtain susceptibility profiles on each bacterial isolate. Study Design Prospective core series. Methods Specimens were collected from the external canals of subjects with clinically diagnosed acute otitis externa. Species‐level identification for each bacterial isolate recovered was obtained by combining phenotypic and genotypic data. End point mean inhibitory concentration (MIC) testing was performed using National Committee for Clinical Laboratory Standards (NCCLS) recommended methods. Results In Alcon‐sponsored clinical studies conducted in 1998 to 2000, microbiology specimens were collected from 2039 subjects (2240 diseased ears) by 101 investigators throughout the United States. A total of 2838 bacteria, 32 yeast, and 17 molds were recovered from 2048 ears clinically diagnosed as acute otitis externa. Of the 202 bacterial species recovered, the species most frequently isolated was Pseudomonas aeruginosa (38%). The next 10 species most frequently isolated were:Staphylococcus epidermidis, 9.1%;Staphylococcus aureus, 7.8%;Microbacterium otitidis, 6.6%;Microbacterium alconae, 2.9%;Staphylococcus caprae, 2.6%;Staphylococcus auricularis, 2.0%;Enterococcus faecalis, 1.9%;Enterobacter cloacae, 1.6%;Staphylococcus capitis subsp. Ureolyticus,1.4%; and Staphylococcus haemolyticus, 1.3%. Susceptibility profiles of S. epidermidis isolates revealed the greatest frequency of high‐level resistance to selected antibiotics (≥8 μg/mL): 23%, neomycin‐resistant; 11%, oxacillin‐resistant; and 12%, ofloxacin‐resistant. Susceptibility profiles of S. aureus isolates revealed a lower frequency of high‐level resistance: 6.3%, neomycin‐resistant; 2.7%, oxacillin‐resistant; and 4.5%, ofloxacin‐resistant. P. aeruginosa with high‐level resistance to quinolones (≥128 mcg/mL for ofloxacin) was recovered from only 1 subject. Likewise, resistance of P. aeruginosa to aminoglycosides was rare. Twenty isolates had neomycin MICs ≥64 mcg/mL and 10 isolates had gentamicin MICs ≥16 mcg/mL. The coryneform isolates identified as Microbacterium otitidis had an intrinsic lack of susceptibility to quinolones (ofloxacin MICs ≥16 mcg/mL) and aminoglycosides (tobramycin MICs ≥32 mcg/mL and gentamicin MICs ≥8 mcg/mL). Conclusions Bacterial infections of the external ear canal are most often caused by P. aeruginosa. However, there are a great number of other gram‐positive and gram‐negative bacterial species that are recovered from patients with acute otitis externa. Because of this diverse etiology, the best topical therapeutic choice for topical therapy is for the most potent, broad‐spectrum (especially anti‐P. aeruginosa) antibiotic available.