# A Novel Earwax Self-Sampling Device: A Feasibility Study
## 4 Discussion
Patients could use it in their own home, sending the samples by post to a specialised clinic/lab. Lessons learned from the current COVID-19 pandemic suggests that in situations when patients may not be able to attend health facilities, self-sampling methods may be a practical solution if devices were enabled to detect putative biomarkers to confirm diagnoses, especially in case of an increased prevalence of common disorders (e.g., [PERSON] et al., 2020)[28]. Importantly, earwax holds similar properties to the beeswax hence is a bacteriostatic agent [7,9] immune to the most common strains of the epidermal flora [8,29]. The self-sampling external ear device is safer than cotton buds because its design cannot harm the eardrum [30] and participants reported no side-effects. Furthermore, the earwaxolytic solution into the tip device has successfully used for treating dermatitis [31], the most commonly associated side-effect by the chronic use of \"cotton buds\" [12]. Depression may be another common disorder which might potentially benefit from the use of earwax, as a potential medium to extract putative biomarkers. A depressive disorder is characterised by chronic cortisol level alteration [32]. Although hair cortisol extraction is a reliable method for measuring that level, it has significant shortcomings [33] and cortisol extraction from earwax might be a viable alternative, as we have recently suggested [34]. There are other clinical earwax extraction methods, apart from the Reiner-Alexander syringe. In the United States, for instance, the majority of the clinicians prefer to extract earwax under microscopic vision, rather than the syringing method we used as a comparator, as this may be more precise [6]. We considered the use of Reiner-Alexander syringe because there is no clear consensus about what constitutes a gold standard earwax removal method, and no previous earwax device was designed for sampling earwax. [PERSON], [PERSON] and [PERSON], (2006) found that endoscopic removal, when compared to microscopic extraction, was less uncomfortable and less painful for patients, as well as easier to perform by non-specialists, a common occurrence outside the United States [35, 36, 37]. However, to our knowledge, no study has ever compared the use of the Reiner-Alexander syringe with either endoscopic or microscopic dewaxing. Both procedures, in comparison to the syringing method that we used are expensive and may be unavailable. Therefore, we used the Reiner-Alexander syringe as a reference test which is largely available \"under reasonable conditions\" an essential characteristic for a gold standard test as suggested by [PERSON] (1992) [38]. In terms of reliability, the clinical method chosen by us showed to be reliable at sampling a small volume of earwax from healthy ears, and the novel method was more effective than the clinical method. Thus, the use of the Reiner-Alexander syringe as a comparison method appears a rational decision based on safety, effectiveness and availability [5]. Although we always checked the otoscopic status after cleaning ears, we never repeated the irrigation using the Reiner-Alexander syringe. Therefore, it might be possible that, if that procedure had been repeated, more earwax would have been extracted. Nonetheless, the evidence for repeating earwax irrigation, if needed, at least using electronic devices is low to moderate [39]. Hence, although speculative, it appears legitimate to think that the Reiner-Alexander may not differ from the earwax irrigation method. Another potential limitation of our study is the fact that the use of common equipment such as earphones or earplugs, may affect the efficiency of the new method by removing earwax to a small extent. Future studies may investigate this potential earwax removal effect. More work could also test the self-sampling earwax device reliability amongst Asian and in people with intellectual disabilities. It has been found that these populations produce a different type and amount of earwax [19; 22].