Ceruminolytics
There is a great need for a better ceruminolytic. A ceruminolytic should disrupt the structural integrity of the keratin sheets and thereby soften, loosen, liquefy, and/or dissolve cerumen and perhaps even float it out. The integrity of the cell membrane is thus reduced, which allows water to pass into the corneocytes along an osmotic gradient. The hydration causes the corneocytes to swell and fragment. The aim of ceruminolysis is to disrupt the keratinocytes on the outside of the plug, as well as those that are located between the plug and the ear canal. Once this is accomplished, the cerumen can be removed by curettage, aspiration, or microdebridement.
The two types of available ceruminolytics are aqueous and organic. Among the aqueous solutions are ordinary water, 10% sodium bicarbonate, 3% hydrogen peroxide, 2% acetic acid, and a combination of 0.5% aluminum acetate and 0.03% benzethonium chloride. Overall, aqueous solutions do a fairly good job of expanding and loosening or dissolving cerumen plugs. Oil-based organic solutions include olive oil, glycerin, propylene glycol, spirit of turpentine, and liquid paraffin. They basically do nothing but lubricate. They do not dissolve or expand corneocytes, and as a result they have no effect on the structural integrity of keratin squames.
Some ceruminolytics--particularly the organic solutions--can cause sensitivity reactions, such as contact dermatitis. Also, a failure to remove cerumen completely can result in a fungal superinfection. Another possible complication is ototoxicity, which can occur if a perforation is present. In many patients, a cerumen plug blocks the view of the tympanic membrane, so we cannot know for certain whether a perforation is present. Nevertheless, we can make an educated guess with a reasonable degree of reliability.
