BACKGROUND: Eczematous external otitis (EEO) is the most difficult-to-treat otitis externa, and characterized by the symptoms of inflammation with hypersensitivity of the external ear canal skin. It is acknowledged as a chronic skin inflammation primarily caused by dermatological and allergic reactions. Food allergens are also considered a cause to induce the inflammation. However, the role of food specific IgG4 in this disease is unclear yet.
METHODS: A 54-year-old woman complained of recurrent itching of the external auditory meatus for 3 years and nails chapping of hands for 2 years.
METHODS: She was diagnosed with EEO and underwent the therapeutic strategy as food elimination of egg, milk and wheat, guided by the result of food specific IgG4 together with probiotics on the basis of previous symptom controlling therapy.
RESULTS: After 17 months\' treatment, she was finally free of all the symptoms and the serum IgG4 specific to all foods are under normal limit.
CONCLUSIONS: To the best of our knowledge, it is the first report revealing the clinical significance of food specific IgG4 in EEO, and the successful treatment with diet elimination guided by food specific IgG4 threw a new light on the clinical management of refractory EEO.

Necrotizing otitis externa (NOE) is a severe infection primarily affecting the external auditory canal, seen mainly in immunocompromised individuals as patients with diabetes mellitus (DM). This case report highlights unusual complications of NOE: temporal bone and nasopharyngeal abscesses. These complications underscore the severity of NOE, particularly when caused by rare pathogens such as Klebsiella species. We detail the case of a 70-year-old male with uncontrolled DM who presented with severe right ear pain, purulent discharge, and significant postauricular swelling. Laboratory investigations revealed elevated inflammatory markers and poorly controlled diabetes. Cultures confirmed Klebsiella pneumoniae, and imaging showed diffuse edema and abscess formation in the temporal bone and nasopharynx. The patient was treated with intravenous Ceftazidime and ciprofloxacin for 6 weeks, followed by oral ciprofloxacin. Effective management of NOE necessitates a comprehensive, multidisciplinary approach. Early intervention, regular monitoring, and imaging are critical for promptly detecting and managing complications.

BACKGROUND: Otitis externa (OE) is one of the most frequently diagnosed dermatological diseases in dogs, having a multifactorial aetiology. Among the bacterial agents associated with canine OE, Pseudomonas aeruginosa is of special concern owing to its frequent multidrug resistance profile and ability to form biofilms related to the infection\'s chronicity and recurrence.
OBJECTIVE: The main objective of this study was to evaluate and compare the antibiofilm activity of two innovative antimicrobials-an otological gel containing a synthetic antimicrobial peptide and Lavandula angustifolia essential oil-with gentamicin (a conventional antibiotic) using biofilm-producing P. aeruginosa isolates obtained from dogs with OE.
METHODS: The biofilm eradication capacity of gentamicin, otological gel and lavender oil was determined against a collection of 12 P. aeruginosa biofilm-producers among 35 clinical isolates obtained from the ear canals of dogs with OE. Also, the antimicrobial activity of the otological gel against P. aeruginosa biofilms was assessed in an in vitro model of dog cerumen.
RESULTS: Lavender oil showed the best effectiveness after 30 min of contact, eradicating 58.3% (seven of 12) of the isolates, and gentamicin showed full eradication (12 of 12) after 24 h. The otological gel acted more slowly than the lavender oil; yet at 24 h, the antibiofilm capacity of both compounds was similar, with no significant difference between them. It also was found that triglycerides from synthetic cerumen earwax had antipseudomonal activity and, when combined with the otological gel, led to the full eradication of P. aeruginosa.
CONCLUSIONS: The results of this in vitro study indicate that lavender oil and the otological gel may be effective topical treatments for canine OE promoted by P. aeruginosa biofilm-producers, as alternatives to gentamicin.

BACKGROUND: Ear cleaning is often recommended for management of canine otitis externa (OE). Few in vivo studies evaluate how ear cleaning affects treatment outcome.
OBJECTIVE: To determine the effect of ear cleaning on canine OE by comparing treatment outcome in cleaned versus noncleaned ears.
METHODS: Twenty-three client-owned dogs with ceruminous or purulent OE.
METHODS: Forty ears were randomised to one of two groups: 20 ears were wiped with dry or saline-moistened gauze (grp1), and 20 external ear canals received manual cleaning (grp2) with a commercial product. One millilitre of a commercial otic suspension containing hydrocortisone aceponate, miconazole nitrate and gentamicin sulfate was applied to affected ears every 24 h for five days. Cytological scores, modified otitis index score (OTIS3), pruritus Visual Analog Scale (PVAS), modified PVAS and client questionnaire were compared on Day (D)0 and D7.
RESULTS: There were no statistical differences between cytological scores, modified OTIS3, PVAS, modified PVAS or client assessments between groups at D7. Both groups had significant reduction in all treatment parameters from D0 to D7 with the exception of cytological rod scores that were only significantly decreased in cleaned ears. There was a significant difference in OTIS3 before and after cleaning on D0.
CONCLUSIONS: Both groups achieved successful outcome regardless of cleaning. Ear cleaning may be more important when rod-shaped bacteria are present.

BACKGROUND: Silver sulfadiazine (SSD) is commonly formulated into otic preparations to treat otitis externa, although evidence of stability and antimicrobial efficacy with long-term storage is lacking.
OBJECTIVE: To evaluate the effect of storage time on chemical stability and in vitro antimicrobial activity of SSD diluted in sterile water, including two 1% suspensions using SSD pharmaceutical-grade powder stored at room temperature (RT) in plastic or sterile glass bottles, and a 1:9 dilution using prescription SSD 1% cream stored at RT in a sterile glass bottle.
METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assessed chemical stability. Trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazole-resistant strains of Staphylococcus pseudintermedius (SP), meticillin-resistant (MR) SP, S. schleiferi (SS), MRSS, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli evaluated by 24 h time-kill analysis assessed in vitro antimicrobial efficacy. Each assessment was performed at zero, one, three and six months of storage.
RESULTS: LC-MS/MS showed no significant change in concentration over time for any suspension. When adjusted for time and species/strain, all SSD suspensions showed significant reductions in colony forming units (cfu)/mL at 24 h (p < 0.001). Including all suspensions, a bactericidal effect (minimum 3-log cfu/mL reduction at 24 h) occurred against 94% of total isolates, with failure against 33 of 552 isolates (6%). Bactericidal failure was more likely with the cream-based suspension (p < 0.05) and at six months (p < 0.01).
CONCLUSIONS: Powder-based and cream-based SSD/sterile water suspensions showed no significant change in concentration and demonstrated in vitro antimicrobial activity for six months. Bactericidal failure was more likely with the cream-based suspension and after six months of storage.

BACKGROUND: Although rare, Malignant otitis externa is responsible for a high morbidity and could sometimes be fatal. The management of this condition is still challenging.
OBJECTIVE: To analyse the clinical, microbiological and radiological profile of malignant otitis externa, and the management of this condition.
METHODS: A descriptive, cross-sectional study was conducted at ENT Department of Kairouan\'s hospital including 38 patients hospitalised and treated for malignant otitis externa from January 2013 to August 2021.
RESULTS: The mean age of patients was 67.7 ± 12.9 years (35-98). All patients presented with continuous otalgia that resists to usual analgesics. Otorrhea was noticed in 76.3% of cases, facial palsy in 2 cases (5.3%) and dysphonia in one case (2.6%). Pseudomonas Aeruginosa was the main responsible pathogen (42%). Concomitant bacterial and fungal infection was noticed in 6.4% of the cases. First-line intravenous antibiotherapy used was mainly based on an association of Cephalosporins and Fluoroquinolones. Complete remission was noticed in 30 patients (79%). However, 8 cases of recurrences (21%) and 2 cases of deaths (5.2%) were noticed in our series. The mean follow-up was 4.6±6.3 (1-26 months).
CONCLUSIONS: Pseudomonas Aeruginosa remains the main responsible pathogen for malignant otitis externa. Nevertheless, fungal infections are rising because of the overuse of antibiotics. Antibiotherapy should be adapted to culture results and resistance profile of pathogens in hospital. Practionners should be aware of the possibility of concomitant fungal infection, especially in the case of unfavorable evolution.

BACKGROUND: Many clinicians prescribe antifungal agents to treat canine otitis externa (OE). However, studies evaluating the antifungal effects of N-acetylcysteine (NAC) and its combinations are limited.
OBJECTIVE: The aim of this study was to evaluate the antifungal effects of NAC alone and in combination with other antifungal agents against Malassezia pachydermatis isolated from canine OE.
METHODS: M. pachydermatis samples were collected from 13 dogs with OE. The final concentration of the inoculum suspensions of M. pachydermatis was 1-5 × 106 colony forming units/mL. The concentrations of the test compounds ketoconazole (KTZ), terbinafine (TER), nystatin (NYS) and NAC were 0.02-300 µg/mL, 0.04-80 µg/mL, 0.16-40 µg/mL and 1.25-20 mg/mL, respectively. The minimum inhibitory concentration (MIC) was measured to evaluate the susceptibility of the M. pachydermatis to KTZ, TER, NYS and NAC. The checkerboard testing method and fractional inhibitory concentration index were used to evaluate the effect of NAC in combination with KTZ, TER and NYS against M. pachydermatis.
RESULTS: The MIC90 values of M. pachydermatis were 4.6875-9.375 µg/mL, 1.25 µg/mL, 5-10 µg/mL and 10 mg/mL for KTZ, TER, NYS and NAC, respectively. The synergistic effects of KTZ, TER and NYS with NAC were identified in 0/13, 2/13 and 0/13 isolates, respectively.
CONCLUSIONS: NAC had an antifungal effect against M. pachydermatis but did not exert synergistic effects when used with KTZ, TER and NYS. Thus, the use of NAC alone as a topical solution could be considered an effective treatment option for canine OE involving M. pachydermatis.

UNASSIGNED: Pseudomonas aeruginosa is a leading cause of canine otitis externa. Enrofloxacin is often applied topically to treat this condition, although recalcitrant and recurring infections are common. There is evidence that exposure to blue light (400-470 nm) has a bactericidal effect on P. aeruginosa and other microorganisms.
UNASSIGNED: In the present study, we tested the biocidal effect of blue light (375-450 nm), alone or in combination with enrofloxacin, against six isolates of P. aeruginosa from dogs with otitis externa (5 of which were resistant to enrofloxacin).
UNASSIGNED: Treatment of planktonic cell cultures with blue light resulted in significant (p < 0.5) reductions in Colony Forming Units (CFU) for all seven strains tested, in some cases below the limit of detection. The greatest bactericidal effect was observed following exposure to light at 405 nm wavelength (p < 0.05). Exposure to blue light for 20 min usually resulted in a greater reduction in Pseudomonas aeruginosa than enrofloxacin treatment, and combination treatment typically resulted in the largest reductions in CFU. Analysis of the genome sequences of these strains established that enrofloxacin resistance was likely the result of a S466F substitution in GyrB. However, there was no clear association between genotype and susceptibility to blue light treatment.
UNASSIGNED: These results suggest that blue light treatment, particularly at 405 nm wavelength, and especially in combination with enrofloxacin therapy, could be an effective treatment for otherwise recalcitrant canine otitis externa caused by Pseudomonas aeruginosa. It may also provide a way of extending the usefulness of enrofloxacin therapy which would otherwise be ineffective as a sole therapeutic agent.

Acute otitis media (AOM) is a common diagnosis in children who present with symptoms of otalgia, fever, or irritability and is confirmed by a bulging tympanic membrane or otorrhea on physical examination. It often is preceded by a viral infection, but the bacterial pathogens isolated most commonly are Streptococcus pneumonia, Haemophilus influenzae, and Moraxella catarrhalis. Watchful waiting may be appropriate in children 6 months or older with uncomplicated unilateral AOM. When antibiotics are indicated, amoxicillin is the first-line treatment in those without recent treatment with or allergy to this drug. Otitis media with effusion (OME) is fluid in the middle ear without symptoms of AOM and typically resolves within 3 months. Tympanostomy tube placement is the most common ambulatory surgery for children in the United States. It is used to ventilate the middle ear space and may be performed to treat recurrent AOM, persistent AOM, or chronic OME. Acute otitis externa is inflammation of the external ear canal, often due to infection. On examination, the ear canal is red and inflamed, with patients typically experiencing discomfort with manipulation of the affected ear. It is treated with a topical antibiotic with or without topical corticosteroid.

Relapsing polychondritis (RPC) is a rare autoimmune condition that often mimics recurrent external otitis. This multisystemic disease primarily affects cartilaginous structures in the body, with the ear pinna being the most commonly impacted. RPC is associated with elevated inflammatory markers and antinuclear antibodies (ANA), and it can lead to chondral destruction. Our case is a 74-year-old Caucasian male with a history of peripheral vascular disease (PVD) who presented to the clinic with recurrent, painful swelling of the right upper ear for 14 days despite multiple antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). He had chronic sensorineural hearing loss in the same ear. He was seen multiple times with identical symptoms in the last seven months and was diagnosed with otitis externa. He denied arthritis, fatigue, rash, abrasion, allergies, trauma, or fever. He was prescribed antimicrobials, alternating NSAIDs, and methylprednisolone with temporary relief. He is only on statins and has an unremarkable family history. He was afebrile with normal vital signs. On physical examination, he was not in acute distress and had a normal voice but had a diffusely erythematous, tender, swollen right ear pinna and external canal sparing the lobe. The rest of the physical examination was unremarkable. Laboratory results showed elevated C-reactive protein (CRP) of 100 mg/L (normal range: <3 mg/L) and erythrocyte sedimentation rate (ESR) of 200 mm/hour (normal range: <20 mm/hour). ANA titer is 1:160 with a homogenous pattern, but other autoantibodies were negative. No red flags were noted on the complete blood count (CBC) or comprehensive metabolic panel (CMP), and his rapid plasma reagin (RPR) test was negative. In this patient, prednisone 60 mg daily was initiated as monotherapy, and rheumatology was also consulted. The patient sought consultation due to recurrent and persistent upper ear infections despite antibiotic treatment and was ultimately diagnosed with a rare medical condition called relapsing polychondritis. Following this treatment, the auricular chondritis improved promptly. The steroid dosage was then slowly tapered and maintained at 10 mg daily to prevent flare-ups. Subsequently, after the initiation of corticosteroids, inflammatory markers trended down to normal levels.