"Do-It-Yourself" Ear Canal Care.

There are a large variety of over-the-counter home remedies and devices for cerumen impaction available in the United States. It is a challenge for clinicians to maintain awareness of the safety and efficacy of these tools, as they are not considered "medical devices" and frequently have no requirement for demonstrating safety or efficacy. This article provides a broad overview of the products being advertised to patients and discusses considerations when recommending home cerumen maintenance.

Prevention of external auditory canal exostosis in the Colorado whitewater community.

CONTEXT: External auditory canal exostoses (EACE) are bony formations that develop insidiously in the auditory meatus from chronic exposure to cold water and, in severe cases, require surgery. This condition has been understudied in the whitewater kayakers and not yet studied in the riverboarding population. Precautions such as earplugs are thought to prevent the formation of EACE because they mechanically block cold water from contacting the sensitive skin in the external auditory canal; however, earplugs are not commonly utilized by athletes. Inquiring about hobbies and the use of protective equipment can be done during osteopathic physicians' preventive care visits. OBJECTIVES: This article aims to determine the prevalence of EACE in Colorado whitewater athletes and their attitudes about wearing ear protection before and after an educational intervention directed at increasing awareness and prevention of EACE. METHODS: In July 2020, participants of this cross-sectional study completed a 10-min survey that collected demographics, whitewater experience, and perceptions of EACE, followed by an educational intervention. Participant ears were photographed utilizing a digital otoscope to assess EACE, and severity ratings were categorized into one of four occlusion levels: none (0%), mild (<25%), moderate (25-75%), or severe (>75%). Spearman correlation coefficients and Wilcoxon signed-rank tests were utilized to assess changes in attitudes before and after the educational intervention. RESULTS: Eighty-one participants (mean [SD] age = 36.3 [12.6] years, 25.9% female) completed the study: 74 kayakers and seven riverboarders. After the intervention, 60.5% (49/81) (p<0.001) reported greater understanding of EACE and 75.0% (60/80) were more likely to wear ear protection (p<0.001). Most (58.0%, 47/81) never wore ear protection. Of the 61 (75.0%) participants with at least one ear severity rating, most (55.7%, 34/61) had moderate EACE, 29.5% (18/61) had no to mild EACE, and 14.8% (9/61) had severe EACE (p<0.001). Impaired hearing was the biggest barrier to utilizing ear protection (51.6%, 33/64). CONCLUSIONS: Our results suggested that the educational intervention improved understanding of EACE and may increase utilization of ear protection in this population. Such prevention efforts may lead to better health of whitewater paddlers by reducing the incidence of EACE. Encouraging osteopathic physicians to inquire about hobbies and protective equipment during primary care preventive visits is essential to help keep athletes in the river doing what they love for longer, contributing to a healthier and happier whole person.

[Modern aspects of inflammatory external ear diseases treatment]. / Sovremennye aspekty lecheniya vospalitel'nykh zabolevanii naruzhnogo ukha.

The article deals with the problem of inflammatory diseases of the external ear. A review of pruritic dermatoses of the external auditory canal was carried out. It has been shown that in chronic dermatoses, the contamination of the skin with bacterial and fungal pathogens significantly increases, which leads to a high risk of developing secondary infectious pathological processes. Treatment of dermatological inflammatory ear diseases includes careful daily hygiene of the external auditory canal and pharmacotherapy, a key aspect of which is the use of topical etiotropic, anti-inflammatory, and symptomatic drugs. The advantage of the combined drug candiderm is described, which, thanks to the unique combination of beclomethasone, gentamicin and clotrimazole in the composition, effectively relieves the symptoms of external ear dermatoses.

Use of lidocaine with phenylephrine (Co-phenylcaine) spray for anaesthesia of the external auditory canal.

OBJECTIVE: A method is described for topical local anaesthesia of the tympanic membrane and ear canal using lidocaine and phenylephrine (Co-phenylcaine) spray and soaked micropatties. DISCUSSION: The advantages of this method are discussed in comparison to existing methods.

The effects of bright light treatment via ear canals on quality of sleep and depressive mood among overworked employees: A randomized-controlled clinical trial.

BACKGROUND: Many overworked employees need tools to improve their depressive mood or sleep disorder. In Finland, a new device of bright light therapy was developed. OBJECTIVE: Our objective was to evaluate the effect of bright light treatment via ear canals on improving the depressive mood and sleep disorder. METHODS: We conducted a randomized, controlled, crossover designed, open-label trial. We examined 27 participants aged 23-52 years, assigned to either Early treatment or Later treatment groups. The Early treatment group used the device on weekdays for the first 4 weeks, followed by a 4-week observation period. The Later treatment group had an observation period for the first 4 weeks, followed by device treatment for the subsequent 4 weeks. Every Friday, the participants were asked to answer questionnaires: A Self-rating Depression Scale (SDS), an Athens Insomnia Scale (AIS), and a Profile of Mood States (POMS) Brief Form. RESULTS: While no significant effect was found on the SDS following treatment (p = 0.16), the AIS showed a significant improvement (p = 0.004), and the scores for the Depression (D) and Vigor (V) of POMs decreased significantly (p = 0.045, p = 0.006, respectively). CONCLUSIONS: Bright light treatment via ear canals may improve sleep quality and depressive mood.

Successful treatment of erythematous-squamous disorders of the external auditory canal with tacrolimus and clotrimazole in otic oil: Our experience in 25 patients.

The external auditory canal (EAC) comprises a special area where erythematous-scaly diseases are located. Among the main dermatoses that can affect EAC seborrheic dermatitis, psoriasis, irritant or allergic contact dermatitis, chronic external otitis (atrial eczematoid dermatitis) and cutaneous lupus should be considered. In this study, 25 consecutive patients were recruited on our dermatological outpatient clinic, 9 men and 16 women, with a clinical diagnosis of localized erythematous-squamous dermatoses in EAC. The mean age was 48.8 years (16-83). The mean time of evolution of the dermatoses was 11.44 months (2-36). Regarding the diagnosis, 14 patients were diagnosed with seborrheic dermatitis (56%), 9 patients with psoriasis (36%), 1 patient with subacute cutaneous lupus (4%), and 1 patient with allergic contact dermatitis to corticosteroids (4%). The indicated treatment was tacrolimus 0.1% and clotrimazole 1% in otic oil, twice a day, for 1 month. The EAC had to be cleaned initially with saline solution impregnated on a swab from the ears. The IGA score and pruritus showed a high results, with important improvement of almost all patients. The satisfaction of the patients obtained with the TSQM-9 questionnaire was 95.2. Retreatment showed an equal efficacy observed during the first treatment period. The efficacy and the absence of side effects with the treatment make this magistral formula an adequate therapeutic option for these dermatoses.

Measurement of Vagus Nerve Response to Transcutaneous Electrical Ear Canal Stimulation in Anesthetized Rat.

Vagus nerve stimulation (VNS) administered to individuals following events such as severe trauma can be a potential therapy to attenuate gut injury and its sequelae. To determine the effective dose of transcutaneous electrical VNS (TE-VNS) and explore an effective method for performing TE-VNS, a measurement system was developed for the detection of vagus nerve response to TE-VNS. In addition, a noise-suppressed transcutaneous electrical stimulator (TES) was constructed for the same purpose. Using these tools, waveforms considered as nerve action potentials were successfully recorded. The recorded waveforms were similar to those evoked by direct electrical stimulation as reported in a latest publication. Our recorded waveforms also varied according to the pulse width of electrical stimulation, indicating the future possibility of determining the potential TES dose.Clinical Relevance- This is a basic research for application to acute therapy of systemic inflammatory response syndrome (SIRS) by transcutaneous electrical stimulation of the vagus nerve.

Effect of different blood groups on tympanometric findings and acoustic reflex thresholds.

PURPOSE: The blood group can have an effect on the auditory system, and it is suggested that it could be an indicator of noise-induced hearing loss. There could be changes in the immittance findings, too, in adults having different blood groups. The present study attempted to determine if there are any differences in tympanometric results (admittance, peak pressure, gradient, resonance frequency, and ear canal volume) and acoustic reflex thresholds (ART) at 500, 1000, 2000 and 4000 Hz between individuals with different blood groups (A positive, B positive, O positive and AB positive). METHODS: Eighty normal hearing adults between the age of 18 and 27 years were considered for the study. They were divided into 20 participants, each with blood groups A, B, AB, and O. The immittance findings were recorded from all the participants of the study. RESULTS: The results showed that the resonance frequency was slightly higher in blood group O compared to other blood groups. Also, the acoustic reflex thresholds were slightly elevated at all frequencies (ipsilateral and contralateral) for individuals with blood group O. CONCLUSIONS: The results of the study suggest possible reduced outer hair cells in persons with blood group O. This could have resulted in elevated acoustic reflex thresholds.

External auditory exostoses and early Neolithic aquatic resource procurement in Cyprus: Results from Cypro-PPNB Kissonerga-Mylouthkia in regional context.

OBJECTIVE: This research is designed to evaluate the occurrence of external auditory exostoses (EAEs) in skeletal remains from the oldest known water wells in the world (Kissonerga-Mylouthkia, Cyprus, 8,200-7,200 BCE). MATERIALS: Six individuals (MNI = 6), five fragmentary temporalia, two preserved auditory canals. METHODS: Macroscopic and microscopic (up to x30) observation, with illumination; presence, type, side, severity, occlusion, number, and position of bony growths recorded. RESULTS: Bony growths within two auditory canals were discovered. Differential diagnosis includes osteomata and external auditory exostoses, with the latter consistent with the bony growths (Grade 1 EAEs, two adult males, one with single, another with two EAEs). CONCLUSIONS: The emergence of the Neolithic in Southwest Asia is thought to involve increases in dietary breadth among foraging societies (Broad-Spectrum Revolution). EAEs likely indicate maritime activity in this context, given the lack of freshwater bodies, and zooarchaeological evidence points to dietary and other uses of maritime organisms. SIGNIFICANCE: This EAE evidence is the oldest known in maritime contexts in Eastern Mediterranean and the Middle East, and first in Cyprus. It contributes towards understanding the initial colonization events by Neolithic farming communities in the 9th millennium BC, and the emergence of broad-spectrum economies at the dawn of the Neolithic in Southwest Asia, crucial for re-considerations of paradigms on the transition to the Neolithic way of life in the Near East. LIMITATIONS: Only a few skeletal remains from these prehistoric contexts were available for observation. SUGGESTIONS FOR FURTHER RESEARCH: Further intensive review of Cypriot skeletal collections for EAEs is advised.

Causality-constrained measurements of aural acoustic reflectance and reflection functions.

Causality-constrained procedures are described to measure acoustic pressure reflectance and reflection function (RF) in the ear canal or unknown waveguide, in which reflectance is the Fourier transform of the RF. Reflectance calibration is reformulated to generate causal outputs, with results described for a calibration based on a reflectance waveguide equation to calculate incident pressure and source reflectance in the frequency domain or source RF in the time domain. The viscothermal model RF of each tube is band-limited to the stimulus bandwidth. Results are described in which incident pressure is either known from long-tube measurements or calculated as a calibration output. Calibrations based on constrained nonlinear optimizations are simpler and more accurate when incident pressure is known. Outputs measured by causality-constrained procedures differ at higher frequencies from those using standard procedures with non-causal outputs. Evanescent-mode effects formulated in the time domain and incorporated into frequency-domain calibrations are negligible for long-tube calibrations. Causal reflectance and RFs are evaluated in an adult ear canal and time- and frequency-domain results are contrasted using forward and inverse Fourier transforms. These results contribute to the long-term goals of improving applications to calibrate sound stimuli in the ear canal at high frequencies and diagnose conductive hearing impairments.

Skill Transference of a Probe-Tube Placement Training Simulator.

BACKGROUND: Probe-tube placement is a necessary step in hearing aid verification which needs ample hands-on experience and confidence before performing in clinic. To improve the methods of training in probe-tube placement, a manikin-based training simulator was developed consisting of a 3D-printed head, a flexible silicone ear, and a mounted optical tracking system. The system is designed to provide feedback to the user on the depth and orientation of the probe tube, and the time required to finish the task. Although a previous validation study was performed to determine its realism and teachability with experts, further validation is required before implementation into educational settings. PURPOSE: This study aimed to examine the skill transference of a newly updated probe-tube placement training simulator to determine if skills learned on this simulator successfully translate to clinical scenarios. RESEARCH DESIGN: All participants underwent a pretest in which they were evaluated while performing a probe-tube placement and real-ear-to-coupler difference (RECD) measurement on a volunteer. Participants were randomized into one of two groups: the simulator group or the control group. During a two-week training period, all participants practiced their probe-tube placement according to their randomly assigned group. After two weeks, each participant completed a probe-tube placement on the same volunteer as a posttest scenario. STUDY SAMPLE: Twenty-five novice graduate-level student clinicians. DATA COLLECTION AND ANALYSIS: Participants completed a self-efficacy questionnaire and an expert observer completed a questionnaire evaluating each participant's performance during the pre- and posttest sessions. RECD measurements were taken after placing the probe tube and foam tip in the volunteer's ear. Questionnaire results were analyzed through nonparametric t-tests and analysis of variance, whereas RECD results were analyzed using a nonlinear mixed model method. RESULTS: Results suggested students in the simulator group were less likely to contact the tympanic membrane when placing a probe tube, appeared more confident, and had better use of the occluding foam tip, resulting in more improved RECD measurements. CONCLUSIONS: The improved outcomes for trainees in the simulator group suggest that supplementing traditional training with the simulator provides useful benefits for the trainees, thereby encouraging its usage and implementation in educational settings.

Establishing critical differences in ear-canal stimulus amplitude for detecting middle ear muscle reflex activation during olivocochlear efferent measurements.

Objective: Assessments of the medial olivocochlear reflex (MOCR) may have clinical utility. The MOCR is measured using contralateral inhibition of otoacoustic emissions but concurrent activation of the middle ear muscle reflex (MEMR) confounds test interpretation. MEMR activation can be detected using the change in ear-canal stimulus amplitude without versus with an MOCR elicitor. This study provides a description of how critical differences in ear-canal stimulus amplitude can be established.Design: Clicks were presented in right ears without and with a contralateral MOCR elicitor. Ear-canal stimulus amplitudes were measured. Two measurements without an elicitor were used to develop critical differences. MEMR activation was considered present if the difference in ear-canal stimulus amplitude without versus with an elicitor exceeded the critical difference.Study sample: Forty-six normal-hearing adults (mean age = 23.4 years, 35 females) participated, with data from 44 participants included in the final analysis.Results: Two participants exceeded the 95% critical difference. The 80, 90 and 99% critical differences are also reported for reference.Conclusions: Results suggest that the contralateral elicitor can evoke the MEMR in a small number of participants. The methods described in this paper can be used for developing equipment- and clinic-specific critical differences for detecting MEMR activation.

Aural stimulation with capsaicin prevented pneumonia in dementia patients.

OBJECTIVE: In the present study, we examined the effects of daily application of capsaicin ointment to the external auditory canal for 6 months on the development of pneumonia in elderly dementia patients at high risk of aspiration. METHODS: Twenty-nine oldest-old bedridden dementia inpatients at high risk of aspiration were enrolled in the present study. Ointment containing 0.025% capsaicin was applied to each external auditory canal with a cotton swab alternatively once a day for 6 months. RESULTS: The incidence of pneumonia during the 6 months before the intervention was 1.80±0.37 in these patients. However, this incidence significantly decreased to 0.40±0.29 (p<0.01) during the 6 months of the alternative application of capsaicin ointment to each auditory canal. No adverse effect such as otalgia was observed. CONCLUSION: These findings suggest that daily long-term aural stimulation with capsaicin ointment enhanced the cough reflex via Arnold's ear-cough reflex as a glottis protective measure, resulting in the reduction of incidence of pneumonia in elderly dementia patients at high risk of aspiration. The daily aural stimulation with capsaicin ointment may be a safe and promising intervention to prevent aspiration pneumonia in elderly people, especially those who cannot undergo swallowing exercise.

Swept-Tone Stimulus-Frequency Otoacoustic Emissions in Human Newborns.

Several types of otoacoustic emissions have been characterized in newborns to study the maturational status of the cochlea at birth and to develop effective tests of hearing. The stimulus-frequency otoacoustic emission (SFOAE), a reflection-type emission elicited with a single low-level pure tone, is the least studied of these emissions and has not been comprehensively characterized in human newborns. The SFOAE has been linked to cochlear tuning and is sensitive to disruptions in cochlear gain (i.e., hearing loss) in adult subjects. In this study, we characterize SFOAEs evoked with rapidly sweeping tones in human neonates and consider the implications of our findings for human cochlear maturation. SFOAEs were measured in 29 term newborns within 72 hr of birth using swept tones presented at 2 oct/s across a four-octave frequency range (0.5­8 kHz); 20 normal-hearing young adults served as a control group. The prevalence of SFOAEs in newborns was as high as 90% (depending on how response "presence" was defined). Evidence of probe-tip leakage and abnormal ear-canal energy reflectance was observed in those ears with absent or unmeasurable SFOAEs. Results in the group of newborns with present stimulus-frequency emissions indicate that neonatal swept-tone SFOAEs are adult-like in morphology but have slightly higher amplitude compared with adults and longer SFOAE group delays. The origin of these nonadult-like features is probably mixed, including contributions from both conductive (ear canal and middle ear) and cochlear immaturities.

Effect of Middle-Ear Pathology on High-Frequency Ear Canal Reflectance Measurements in the Frequency and Time Domains.

The effects of middle-ear pathology on wideband acoustic immittance and reflectance at frequencies above 6-8 kHz have not been documented, nor has the effect of such pathologies on the time-domain reflectance. We describe an approach that utilizes sound frequencies as high as 20 kHz and quantifies reflectance in both the frequency and time domains. Experiments were performed with fresh normal human temporal bones before and after simulating various middle-ear pathologies, including malleus fixation, stapes fixation, and disarticulation. In addition to experimental data, computational modeling was used to obtain fitted parameter values of middle-ear elements that vary systematically due to the simulated pathologies and thus may have diagnostic implications. Our results demonstrate that the time-domain reflectance, which requires acoustic measurements at high frequencies, varies with middle-ear condition. Furthermore, the extended bandwidth frequency-domain reflectance data was used to estimate parameters in a simple model of the ear canal and middle ear that separates three major conductive pathologies from each other and from the normal state.

A comparison of ear-canal-reflectance measurement methods in an ear simulator.

Ear-canal reflectance has been researched extensively for diagnosing conductive hearing disorders and compensating for the ear-canal acoustics in non-invasive measurements of the auditory system. Little emphasis, however, has been placed on assessing measurement accuracy and variability. In this paper, a number of ear-canal-reflectance measurement methods reported in the literature are utilized and compared. Measurement variation seems to arise chiefly from three factors: the residual ear-canal length, the ear-probe insertion angle, and the measurement frequency bandwidth. Calculation of the ear-canal reflectance from the measured ear-canal impedance requires estimating the ear-canal characteristic impedance in situ. The variability in ear-canal estimated characteristic impedance and reflectance due to these principal factors is assessed in an idealized controlled setup using a uniform occluded-ear simulator. In addition, the influence of this measurement variability on reflectance-based methods for calibrating stimulus levels is evaluated and, by operating the condenser microphone of the occluded-ear simulator as an electro-static speaker, the variability in estimating the emitted pressure from the ear is determined. The various measurement methods differ widely in their robustness to variations in the three principal factors influencing the accuracy and variability of ear-canal reflectance.

On the calculation of reflectance in non-uniform ear canals.

Ear-canal reflectance is useful for quantifying the conductive status of the middle ear because it can be measured non-invasively at a distance from the tympanic membrane. Deriving the ear-canal reflectance requires decomposing the total acoustic pressure into its forward- and reverse-propagating components. This decomposition is conveniently achieved using formulas that involve the input and characteristic impedances of the ear canal. The characteristic impedance is defined as the ratio of sound pressure to volume flow of a propagating wave and, for uniform waveguides, the plane-wave characteristic impedance is a real-valued constant. However, in non-uniform waveguides, the characteristic impedances are complex-valued quantities, depend on the direction of propagation, and more accurately characterize a propagating wave in a non-uniform ear canal. In this paper, relevant properties of the plane-wave and spherical-wave characteristic impedances are reviewed. In addition, the utility of the plane-wave and spherical-wave reflectances in representing the reflection occurring due to the middle ear, calibrating stimulus levels, and characterizing the emitted pressure in simulated non-uniform ear canals is investigated and compared.

Osteonecrosis of the External Auditory Canal Associated With Oral Sorafenib Therapy: Sorafenib and Temporal Bone Osteonecrosis.

OBJECTIVE: To present the first case of osteonecrosis of the external auditory canal associated with sorafenib treatment. PATIENT: 58-year-old patient with right-sided otorrhea and otalgia was treated for otitis externa for 1 month without improvement. Otoscopic examination revealed a large defect in the inferior wall of the tympanic bone filled with skin debris and bony fragments. Previous medical history included treatment with sorafenib for metastatic renal cell cancer; he had never been exposed to radiotherapy. Computed tomography of the temporal bone showed a large right external auditory canal bony erosion with involvement of the tympanic bone and bony sequestra extending to the mastoid cells and temporomandibular joint. Histologic examination revealed necrotic bone and inflammatory changes with no signs of malignancy. A diagnosis of osteonecrosis of external auditory canal was made. INTERVENTION: Right subtotal petrosectomy with obliteration of surgical cavity with abdominal fat was performed. RESULTS: Final histological report revealed avascular necrosis of the bone with perivascular lymphocitic infiltration of the soft tissues. Diagnosis of medication-related external auditory canal osteonecrosis was confirmed. CONCLUSION: Medication-related osteonecrosis of the temporal bone is not a well-known entity among otolaryngologists and could therefore be misclassified as another diagnosis. In patients with othorrea and earache following sorafenib treatment, temporal bone osteonecrosis should be suspected.

Single Dose Topical Application of Clotrimazole for the Treatment of Otomycosis: Is This Enough?

BACKGROUND AND OBJECTIVES: To determine the efficacy of filling the external auditory meatus with 1% clotrimazole at a single visit for the treatment of otomycosis. SUBJECTS AND METHODS: This prospective study included 40 patients who were referred to our clinic with complaints of ear itching, pain, and fullness, and were diagnosed with unilateral otomycosis. After cleaning the mycotic hyphae from the external auditory meatus, the ear canal was filled with 1% clotrimazole, using an intravenous catheter and syringe. The patients received follow-up examinations on post-treatment days 7, 15, and 45. RESULTS: The follow-up otomicroscopic examinations revealed that 95% of the ear canals were entirely clean and that all symptoms had resolved. The post-treatment scores of pain, aural fullness and itching were significantly lower than the pre-treatment scores (p < 0.01). CONCLUSIONS: Filling the external auditory meatus with 1% clotrimazole at a single visit is an easy, efficient, and cost-effective treatment for otomycosis. Additionally, high patient compliance makes this treatment superior to long-term topical therapy.

Ear drops for the removal of ear wax.

BACKGROUND: Ear wax (cerumen) is a normal bodily secretion that can become a problem when it obstructs the ear canal. Symptoms attributed to wax (such as deafness and pain) are among the commonest reasons for patients to present to primary care with ear trouble.Wax is part of the ear's self-cleaning mechanism and is usually naturally expelled from the ear canal without causing problems. When this mechanism fails, wax is retained in the canal and may become impacted; interventions to encourage its removal may then be needed. Application of ear drops is one of these methods. Liquids used to remove and soften wax are of several kinds: oil-based compounds (e.g. olive or almond oil); water-based compounds (e.g. sodium bicarbonate or water itself); a combination of the above or non-water, non-oil-based solutions, such as carbamide peroxide (a hydrogen peroxide-urea compound) and glycerol. OBJECTIVES: To assess the effects of ear drops (or sprays) to remove or aid the removal of ear wax in adults and children. SEARCH METHODS: We searched the Cochrane ENT Trials Register; Cochrane Register of Studies; PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 23 March 2018. SELECTION CRITERIA: Randomised controlled trials (RCTs) in which a 'cerumenolytic' was compared with no treatment, water or saline, an alternative liquid treatment (oil or almond oil) or another 'cerumenolytic' in adults or children with obstructing or impacted ear wax. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. The primary outcomes were 1) the proportion of patients (or ears) with complete clearance of ear wax and 2) adverse effects (discomfort, irritation or pain). Secondary outcomes were: extent of wax clearance; proportion of people (or ears) with relief of symptoms due to wax; proportion of people (or ears) requiring further intervention to remove wax; success of mechanical removal of residual wax following treatment; any other adverse effects recorded and cost. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. MAIN RESULTS: We included 10 studies, with 623 participants (900 ears). Interventions included: oil-based treatments (triethanolamine polypeptide, almond oil, benzocaine, chlorobutanol), water-based treatments (docusate sodium, carbamide peroxide, phenazone, choline salicylate, urea peroxide, potassium carbonate), other active comparators (e.g. saline or water alone) and no treatment. Nine of the studies were more than 15 years old.The overall risk of bias across the 10 included studies was low or unclear. PRIMARY OUTCOME: proportion of patients (or ears) with complete clearance of ear waxSix studies (360 participants; 491 ears) contributed quantitative data and were included in our meta-analyses.Active treatment versus no treatmentOnly one study addressed this comparison. The proportion of ears with complete clearance of ear wax was higher in the active treatment group (22%) compared with the no treatment group (5%) after five days of treatment (risk ratio (RR) 4.09, 95% confidence interval (CI) 1.00 to 16.80); one study; 117 ears; NNTB = 8) (low-quality evidence).Active treatment versus water or salineWe found no evidence of a difference in the proportion of patients (or ears) with complete clearance of ear wax when the active treatment group was compared to the water or saline group (RR 1.47, 95% CI 0.79 to 2.75; three studies; 213 participants; 257 ears) (low-quality evidence). Two studies applied drops for five days, but one study only applied the drops for 15 minutes. When we excluded this study in a sensitivity analysis it did not change the result.Water or saline versus no treatmentThis comparison was only addressed in the single study cited above (active versus no treatment) and there was no evidence of a difference in the proportion of ears with complete wax clearance when comparing water or saline with no treatment after five days of treatment (RR 4.00, 95% CI 0.91 to 17.62; one study; 76 ears) (low-quality evidence).Active treatment A versus active treatment BSeveral single studies evaluated 'head-to-head' comparisons between two active treatments. We found no evidence to show that one was superior to any other.Subgroup analysis of oil-based active treatments versus non-oil based active treatmentsWe found no evidence of a difference in this outcome when oil-based treatments were compared with non-oil-based active treatments. PRIMARY OUTCOME: adverse effects: discomfort, irritation or painOnly seven studies planned to measure and did report this outcome. Only two (141 participants;176 ears) provided useable data. There was no evidence of a significant difference in the number of adverse effects between the types of ear drops in these two studies. We summarised the remaining five studies narratively. All events were mild and reported in fewer than 30 participants across the seven studies (low-quality evidence).Secondary outcomesThree studies reported 'other' adverse effects (how many studies planned to report these is unclear). The available information was limited and included occasional reports of dizziness, unpleasant smell, tinnitus and hearing loss. No significant differences between groups were reported. There were no emergencies or serious adverse effects reported in any of the 10 studies.There was very limited or no information available on our remaining secondary outcomes. AUTHORS' CONCLUSIONS: Although a number of studies aimed to evaluate whether or not one type of cerumenolytic is more effective than another, there is no high-quality evidence to allow a firm conclusion to be drawn and the answer remains uncertain.A single study suggests that applying ear drops for five days may result in a greater likelihood of complete wax clearance than no treatment at all. However, we cannot conclude whether one type of active treatment is more effective than another and there was no evidence of a difference in efficacy between oil-based and water-based active treatments.There is no evidence to show that using saline or water alone is better or worse than commercially produced cerumenolytics. Equally, there is also no evidence to show that using saline or water alone is better than no treatment.