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: 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.

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.

UNASSIGNED: This study intended to assess the level of awareness and attitude toward otitis externa (OE) and specific limitations that counter the attempts to uplift the understanding and notion related to OE among the general population of Saudi Arabia.
UNASSIGNED: A cross-sectional quantitative study using a questionnaire was done via Google Forms between May 2023 and July 2023. The scoring method was used to determine the participant\'s awareness or attitude; participants who scored >50% were considered aware or to have a good attitude.
UNASSIGNED: Approximately 52.2% had a good attitude toward the OE, and majority were willing to visit healthcare professionals (81%) to provide care and receive proper education during office visits (80.1%). Of all the participants, 69%, 33.4%, and 30.8% suggested that a lack of awareness, cost, and health insurance, respectively, might prevent patients from seeking a healthcare professional. Only 10.9% of participants demonstrated good awareness (score >13) of outer ear inflammation.
UNASSIGNED: The findings indicate a poor level of awareness regarding OE, and a positive attitude toward seeking healthcare, with the majority recommending professional visits and relying on healthcare professionals for information.

The increasing emergence of Staphylococcus aureus as the primary causative agent of otitis externa has been noted; however, detailed information regarding the molecular characteristics of these strains in Iran remains scarce. The current study aims to investigate both genotypic and phenotypic attributes of S. aureus strains implicated in ear infections. In the present work, we analyzed 60 S. aureus strains isolated from cases of otitis externa over a period of 45 months. The resistance patterns were determined using disk diffusion and microbroth dilution methods. All S. aureus isolates were confirmed by the nucA polymerase chain reaction assay, and their biofilm production was assessed by a microtiter plate assay. Molecular characterization of the isolates was performed using the staphylococcal cassette chromosome mec, multilocus sequence typing, and staphylococcus protein A typing methods. Overall, the results indicated that 44 out of 60 S. aureus isolates (73.3 %) were methicillin-resistant Staphylococcus aureus. Resistance to mupirocin and vancomycin was observed in 13.3 % and 1.7 % of the tested isolates, respectively. Furthermore, out of the 60 S. aureus isolates, 56 strains (93.4 %) were classified as positive biofilm strains at different levels. Twelve distinct clonal lineages were identified. The vast majority of S. aureus isolates belonged to CC30/ST30-MRSA IV/t019 (41.7 %). Among the 31 strong biofilm producers, the majority (64.5 %) belonged to CC30/ST30-MRSA IV/t019 clone. Biofilm negative isolates belonged to CC22/ST22 (2 isolates), CC8/ST585 (one isolate), and CC8/ST8 (one isolate). Our result revealed that about three-quarters of PVL-positive strains belonged to CC30/ST30. Our data confirmed the presence of MSSA strains among CC30/ST30 and CC22/ST22 isolates. The mupirocin resistant isolates (n = 8) belonged to CC8/ST585-MRSA III/t713 (37.5 %), CC8/ST239-MRSA III/t030 (25 %), CC8/ST8-MRSA IV/t008 (12.5 %), CC8/ST239-MRSA III/t037 (12.5 %), and CC22/ST22-MRSA IV/t790 (12.5 %) lineages. The VRSA strain belonged to the CC8/ST8-MRSA IV/t008 lineage, carrying the vanA determinant. iMLSB phenotypes (n = 14) were distributed across different lineages, including CC30/ST30-MRSA IV/t019 (21.5 %), CC30/ST30-MSSA/t021 (21.5 %), CC22/ST22-MSSA/t005 (14.3 %), CC8/ST239-MRSA III/t030 (14.3 %), CC22/ST22-MSSA/t1869 (7.1 %), CC22/ST22-MRSA IV/t790 (7.1 %), CC8/ST239-MRSA III/t037 (7.1 %), and CC1/ST772-MRSA IV/t10795 (7.1 %). These findings highlight significant genotypic diversity and high biofilm formation among our isolates. The frequent occurrence of the CC/ST30 clone in S. aureus strains isolated from otitis externa reflects the emergence of these lineages as a predominant clone in Iran, posing a significant public health concern.

Otitis externa is an inflammatory and infectious disease that affects the external auditory canal. The term otorrhea refers to the outflow of discharge from the ear which is one of the main symptoms of otitis externa along with inflammation. External ear canal pathology or middle ear illness with tympanic membrane perforation is the etiological factor of otorrhea. Otorrhea is an indication of infection. Antimicrobial agents are the conventional treatment of various bacterial and fungal infections, but they have impediments such as resistance development, side effects, patient affordability, etc. The Gandhak Rasayana formulation mentioned in the Ayurvedic text can be a good option for the treatment of various infectious diseases. Karnasrava is a type of ear disease referred to as Vata predominant Tridoshaja disease and it is curable. The term Karnasrava signifies discharge from ear and is self-explanatory. Karnasrava consists of a wide spectrum of diseases and can have a near correlation with otitis externa as per signs and symptoms. Gandhak Rasayana exhibited significant antibacterial, antifungal and anti-inflammatory activity in otitis externa. Evaluating its antibacterial and antifungal activity can provide scientific evidence for the study through the present case report. A 31-year-old male patient registered in OPD at Sane Guruji Hospital, Hadapsar, Pune was clinically diagnosed as Karnasrava (Otitis externa) and pus culture positive for Klebsiella species. We started the treatment with Gandhak Rasayana-an Ayurvedic formulation of 250mg two tablets in the morning and evening with lukewarm water for 21 days. The outcome of the treatment was observed as a reduction in Karnashula (otalgia), Karnasrava (ear discharge), Karnakandu (itching), ear blockage and inflammatory changes. Post-treatment culture was negative for the organism. The improvement was noted in Brighton grading scale from grade III to grade I. Gandhak Rasayana showed significant antibacterial activity in the present case. Evaluating its antibacterial, antifungal and anti-inflammatory activity can provide scientific evidence for the study.

BACKGROUND: Growing antibiotic resistance has made treating otitis externa (OE) increasingly challenging. On the other hand, local antimicrobial treatments, especially those that combine essential oils (EOs) with nanoparticles, tend to be preferred over systemic ones. It was investigated whether Ajwain (Trachyspermum ammi) EO, combined with chitosan nanoparticles modified by cholesterol, could inhibit the growth of bacterial pathogens isolated from OE cases in dogs. In total, 57 dogs with clinical signs of OE were examined and bacteriologically tested. Hydrogels of Chitosan were synthesized by self-assembly and investigated. EO was extracted (Clevenger machine), and its ingredients were checked (GC-MS analysis) and encapsulated in chitosan-cholesterol nanoparticles. Disc-diffusion and broth Micro-dilution (MIC and MBC) examined its antimicrobial and therapeutic properties.
RESULTS: Staphylococcus pseudintermedius (49.3%) was the most common bacteria isolated from OE cases, followed by Pseudomonas aeruginosa (14.7%), Escherichia coli (13.3%), Streptococcus canis (9.3%), Corynebacterium auriscanis (6.7%), Klebsiella pneumoniae (2.7%), Proteus mirabilis (2.7%), and Bacillus cereus (1.3%). The investigation into the antimicrobial properties of Ajwain EO encapsulated in chitosan nanoparticles revealed that it exhibited a more pronounced antimicrobial effect against the pathogens responsible for OE.
CONCLUSIONS: Using chitosan nanoparticles encapsulated with EO presents an effective treatment approach for dogs with OE that conventional antimicrobial treatments have not cured. This approach not only enhances antibacterial effects but also reduces the required dosage of antimicrobials, potentially preventing the emergence of antimicrobial resistance.

The development of a non-invasive method to analyze cytokine expression in the skin will provide further understanding of inflammatory skin disorders. This study aimed to evaluate cytokine expression in the skin through cerumen swabbing in dogs with otitis externa (OE) and to investigate whether increased cytokine expression in infected OE reflects the inflammatory status of the ear canal. Three groups consisting of control dogs (n = 24), dogs with ceruminous Malassezia OE (n = 25), and dogs with suppurative bacterial OE (n = 15) were included in the study. The concentrations of keratinocyte-derived cytokines including Interleukin (IL)-8/chemokine ligand (CXCL)8, IL-10, IL-6, Tumor necrosis factor (TNF)-α, and IL-1ß in the cerumen of the ear canal of the included patients were analyzed using commercial ELISA kits. Additionally, correlations between cytokine levels and cytology scores (of Malassezia yeasts, cocci/rod-shaped bacteria, and inflammatory cells) were assessed. IL-8/CXCL8 concentrations were significantly higher in dogs with ceruminous Malassezia OE and dogs with suppurative bacterial OE than in control dogs. Furthermore, IL-8/CXCL8 concentrations positively correlated with Malassezia scores in dogs with ceruminous OE (r = 0.630) and with bacterial scores in dogs with suppurative OE (r = 0.601). In addition, increased expression of IL-6 and IL-1ß were detected in dogs with suppurative bacterial OE compared to those with Malassezia OE and control dogs, and showed positive correlation with inflammatory cell scores IL-6 r = 0.520, IL-1ß; r = 0.680). Therefore, keratinocyte-derived cytokines could be evaluated using non-invasive methods such as cerumen swabbing in dogs with OE.

OBJECTIVE: Achromobacter xylosoxidans is an emerging pathogen mainly associated with resistant nosocomial infections. This bacteria had been isolated in the ear together with other pathogens in cultures from patients with chronic otitis media, but it had never been reported as a cause of osteomyelitis of the external auditory canal.
METHODS: We present a unique case of a healthy 81-year-old woman who presented with left chronic otorrhea refractory to topical and oral antibiotic treatment. Otomicroscopy revealed an erythematous and exudative external auditory canal (EAC) with scant otorrhea. The tympanic membrane was intact, but an area of bone remodeling with a small cavity anterior and inferior to the bony tympanic frame was observed. Otic culture isolated multi-drug-resistant A. xylosoxidans, only sensitive to meropenem and cotrimoxazole. Temporal bone computed tomography showed an excavation of the floor of the EAC compatible with osteomyelitis. Targeted antibiotherapy for 12 weeks was conducted, with subsequent resolution of symptoms and no progression of the bone erosion.
CONCLUSIONS: Atypical pathogens such as A. xylosoxidans can be the cause of chronic otitis externa. Early diagnosis and specific antibiotherapy can prevent the development of further complications, such as osteomyelitis. In these cases, otic cultures play an essential role to identify the causal germ. This is the first case of EAC osteomyelitis due to A. xylosoxidans reported to date.