Ear wax

Abstract

Introduction

Ear wax only becomes a problem if it causes a hearing impairment or other ear-related symptoms. Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by the use of hearing aids, or by the use of cotton buds to clean the ears. Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes.

Methods and outcomes

We conducted a systematic review and aimed to answer the following clinical question: What are the effects of methods to remove ear wax? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2007 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

Results

We found nine systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

Conclusions

In this systematic review, we present information relating to the effectiveness and safety of the following interventions: ear syringing; manual removal (other than ear syringing); and wax softeners (alone or prior to syringing).

Key Points

Ear wax only becomes a problem if it causes a hearing impairment, or other ear-related symptoms.

• Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by hearing aids, or by the use of cotton buds to clean the ears.

• Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes.

For such a commonly occurring condition, there is little high-quality evidence available to guide practice.

Ear syringing is generally considered to be effective, but evidence is limited.

• Syringing can clear wax from the ear canal in up to 100% of ears when performed alone, or after the use of wax softeners.

• Ear syringing may be associated with vertigo and tympanic membrane perforation in some people. Pain, damage to the skin of the ear canal, and otitis externa are other possible adverse effects.

Other mechanical methods of removing ear wax by trained staff using instruments — such as microsuction — are probably effective, although the evidence is limited.

• Mechanical removal of wax with suction, probes, or forceps is considered effective, but can cause trauma to the ear canal, depending on the experience and training of the operator, and the adequacy of visualisation.

Benefits of wax softeners are unknown when used prior to syringing or alone.

• The use of wax softeners prior to syringing may increase clearance rate, but the evidence is limited.

• Evidence is too limited to show whether wax softeners alone are effective in clearing wax, or whether one type of softener is more effective than another.

About this condition

Definition

Ear wax is normal and becomes a problem only if it produces hearing impairment, pain, or other ear-related symptoms. Ear wax may also need to be removed if it prevents inspection of the ear drum. The term ”impacted wax” is used in different ways, and can merely imply the coexistence of wax obscuring the ear drum with symptoms in that ear.

Incidence/ Prevalence

We found four surveys of the prevalence of impacted wax. The studies were carried out in a variety of populations, and used a variety of definitions of impacted wax. Prevalence ranged from 7% to 35%. It is unclear how these figures relate to prevalence in the general population.

Aetiology/ Risk factors

Factors that prevent the normal extrusion of wax from the ear canal (e.g., wearing a hearing aid, using cotton buds to clean ears) increase the chance of ear wax accumulating.

Prognosis

Most ear wax emerges from the external canal spontaneously; one small RCT that included a no-treatment group found that 32% of ears with impacted wax showed some degree of spontaneous resolution after 5 days (26% described as moderately clear; 5% described as completely clear). Without impaction or adherence to the drum, there is likely to be minimal, if any, hearing loss.

Aims of intervention

To relieve symptoms or to allow examination, especially of the tympanic membrane, by completely removing impacted wax or visually obstructing wax; and to ease wax removal.

Outcomes

Treatment success: proportion of people (or ears) with relief of hearing loss or discomfort; subjective assessment of amount of wax remaining; after use of wax softeners prior to cleansing: proportion of people requiring mechanical removal to improve symptoms; degree of visualisation of the tympanic membrane; perceived ease of mechanical removal (measured, for example, by the volume of water used to accomplish successful syringing).

Methods

Clinical Evidence search and appraisal June 2007. The following databases were used to identify studies for this systematic review: Medline 1966 to June 2007, Embase 1980 to June 2007, and The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2007, Issue 2. Additional searches were carried out using these websites: NHS Centre for Reviews and Dissemination (CRD) — for Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and NICE. We also searched for retractions of studies included in the review. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the author for additional assessment, using pre-determined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews and RCTs in any language, at least single blinded, and containing more than 20 individuals of whom more than 80% were followed up. There was no minimum length of follow-up required to include studies. We excluded all studies described as “open”, “open label”, or not blinded, unless blinding was impossible. We also searched for prospective and retrospective cohort studies on the manual removal methods, and on harms of included interventions. In addition, we use a regular surveillance protocol to capture harms alerts from organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the reviews as required. We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table). The categorisation of the quality of the evidence (high, moderate, low, or very low) reflects the quality of evidence available for our chosen outcomes in our defined populations of interest. These categorisations are not necessarily a reflection of the overall methodological quality of any individual study, because the Clinical Evidence population and outcome of choice may represent only a small subset of the total outcomes reported, and population included, in any individual trial. For further details of how we perform the GRADE evaluation and the scoring system we use, please see our website (www.clinicalevidence.com).

Table.

GRADE Evaluation of interventions for Ear wax.

Important outcomes	Treatment success
Studies (Participants)	Outcome	Comparison	Type of evidence	Quality	Consistency	Directness	Effect size	GRADE	Comment
What are the effects of methods to remove ear wax?
1 (26)	Treatment success	Ear syringing with prior water instillation versus ear syringing without prior water instillation	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, subjective assessment of outcome and manual syringing
1 (100)	Treatment success	Endoscopic vision versus microscopic vision to assist mechanical dewaxing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, incomplete reporting of results and blinding flaws
1 (45)	Treatment success	Water-based wax softeners prior to syringing versus no treatment	4	–3	0	–1	0	Very low	Quality points deducted for sparse data, incomplete reporting of results, blinding flaws and including RCTs of poor methodologies. Directness point deducted for uncertainty about method of syringing
5 (258)	Treatment success	Water-based wax softeners prior to syringing versus saline	4	–2	0	0	0	Low	Quality points deducted for including RCTs of poor methodologies and for incomplete reporting of results
5 (523)	Treatment success	Water-based wax softeners versus oil-based wax softeners prior to syringing	4	–1	0	0	0	Moderate	Quality point deducted for including RCTs of poor methodologies
4 (190)	Treatment success	Water-based wax softeners versus each other prior to syringing	4	–2	0	0	0	Low	Quality points deducted for sparse data and for including RCTs of poor methodologies
4 (381)	Treatment success	Oil-based wax softeners versus each other prior to syringing	4	–2	0	0	0	Low	Quality points deducted for incomplete reporting of results and for including RCTs of poor methodologies
2 (at least 76 people)	Treatment success	Non-water, non-oil based wax softeners versus water-based or oil-based preparations prior to syringing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, incomplete reporting of results and for including RCTs of poor methodologies
1 (population details not reported)	Treatment success	Wax softeners alone versus wax softeners plus syringing	4	–2	0	–1	0	Very low	Quality points deducted for sparse data and incomplete reporting of results. Directness point deducted for uncertainty of benefit from treatment.
1 (97)	Treatment success	Wax softeners versus no treatment	4	–3	0	–2	0	Very low	Quality points deducted for sparse data, incomplete reporting of results, and methodological flaws (no intention-to-treat analysis, uncertainties about blinding, randomisation and duration of treatment). Directness points deducted for differences in occlusion at baseline and uncertainty about inclusion criteria
1 (97)	Treatment success	Wax softeners versus sterile water	4	–3	0	–2	0	Very low	Quality points deducted for sparse data, incomplete reporting of results, and methodological flaws (no intention-to treat analysis, uncertainties about blinding, randomisation and duration of treatment, and no statistical difference between groups). Directness points deducted for differences in occlusion at baseline and uncertainty about inclusion criteria
2 (91)	Treatment success	Water-based wax-softener versus saline	4	-3	0	-2	0	Very low	Quality points deducted for sparse data, and methodological flaws (no intention-to-treat analysis, uncertainties about blinding, randomisation and duration of treatment). Directness points deducted for differences in occlusion at baseline and uncertainty about inclusion criteria
4 (215)	Treatment success	Water-based wax softeners versus each other	4	–3	0	–2	0	Very low	Quality points deducted for incomplete reporting of results and methodological flaws (no intention-to-treat analysis, uncertainties about blinding, randomisation and duration of treatment). Directness points deducted for differences in occlusion at baseline, uncertainty about inclusion criteria, and for assessment of different populations (ears in one RCT and people in the second RCT)
2 (86)	Treatment success	Non-water, non-oil wax-softener versus oil-based wax softener	4	–3	0	–2	0	Very low	Quality points deducted for sparse data, incomplete reporting of results and methodological flaws (no intention-to-treat analysis, uncertainties about blinding, randomisation and duration of treatment). Directness points deducted for differences in occlusion at baseline and uncertainty about inclusion criteria
1 (106)	Treatment success	Oil-based wax softeners versus each other	4	–3	0	–2	0	Very low	Quality points deducted for sparse data, incomplete reporting of results, and methodological flaws (no intention to-treat analysis, uncertainties about blinding, randomisation and duration of treatment). Directness points deducted for differences in occlusion at baseline and uncertainty about inclusion criteria

We initially allocate 4 points to evidence from RCTs, and 2 points to evidence from observational studies. To attain the final GRADE score for a given comparison, points are deducted or added from this initial score based on preset criteria relating to the categories of quality, directness, consistency, and effect size. Quality: based on issues affecting methodological rigour (e.g., incomplete reporting of results, quasi-randomisation, sparse data [<200 people in the analysis]). Consistency: based on similarity of results across studies. Directness: based on generalisability of population or outcomes. Effect size: based on magnitude of effect as measured by statistics such as relative risk, odds ratio, or hazard ratio.

Glossary

Impacted wax

Wax that has been compressed in the ear canal, completely obstructing the lumen. In practice, many RCTs define impaction as the presence of symptoms associated with wax obscuring the ear drum.

Low-quality evidence

Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Moderate-quality evidence

Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.

Obstructing wax

Wax that obscures direct vision of the ear drum.

Very low-quality evidence

Any estimate of effect is very uncertain.

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