What can you do when patients say their hearing aids are making their ears itch?

Question

Answer

The ear canal has a very delicate skin; even a stray hair in the ear canal may cause itching.  Considering that level of sensitivity, it’s no wonder itching or irritation will be a common complaint from the hearing aid user who comes in for a follow up visit. A 1991 study¹ showed 39% of earmold users experience itching as a side effect, and this statistic may not have changed much even though many today are fit with instant fit domes. In most cases, itching diminishes over time as people become accustomed to the sensation in their ear canals, but there are also cases that need our attention, such as poor fit or allergy to materials.

Instant fit domes

Instant fit domes are made from medical grade silicone. This means that an allergic reaction is less likely than for a custom ear mold. However, some patients can be allergic to the cleaning agent used to clean the dome. For example, chlorohexadine is a commonly used disinfectant in the clinic that can trigger allergic reactions in some individuals. An allergic reaction will usually occur within 12 to 48 hours following contact. Chlorohexadine can also be the culprit of itchy ears due to dermatitis, which can look like an allergic reaction but does not occur as quickly. In either case, using a cleaning product that does not contain the offending ingredient is key.

Open fitting

One of the most common causes of itching for open fitting is poor physical fit. Whether it is thin tube or receiver in the ear (RIE) style, we are often dealing with instant fit domes along with limited tube/receiver length and dome sizes to select. The physical fit won’t always be perfect. When patients complain about itching/irritation and they are fit open, the first place to look for issues is the physical fit. Is the thin tube too short, pulling the skin of the ear too tight? Or is it too long, leaving the hearing aid dangling insecurely above the ear? Too short will cause pressure to the skin; too long and the hearing aid may move easily and cause irritation when the person moves their head. Is the dome size right? Try to change the dome size or change to a different type of dome, such as from a “closed” dome to a “tulip” dome. Does the dome go too deep or too shallow into the canal?  For RIE hearing aids, if the audiogram falls in the fitting range of different power level of receivers, try a receiver of a different power level. Sometimes the slight difference in size can make a big difference in how the receiver rests in the ear canal and feels for the patient. If the physical fit is good, but the patient still complains about irritation, try applying a little bit of lubricant (such as Eargene or Otoease) to the dome. In case of continued itching, a custom earmold may be the solution.

Closed fitting

For closed fittings with custom earmold/shell, itching can be due to poor fit, allergy to the earmold materials, moisture in the ear, or wax accumulation. Have a look at the ear and ask the patient which part is causing the itching; the patient often will guide us to find the irritation point. Check if there is wax accumulation in the ear canal, any localized redness, or swelling. If there is not localized redness, try using something like a Q tip to touch the ear to find the irritation location. Also check the earmold to see if there is moisture in the sound tube or on the earmold surface. With perspiration in the ear canal, the moisture between the earmold and ear canal wall will likely cause itching. The extra moisture also encourages the growth of bacteria and/or fungus, leading to an itchy infection.

Poor fit is a common cause of itching with earmolds as well as it is with instant fit tubes and domes. In the 1991 study cited above, no objective changes were observed in 38% of the itching ears, and in cases where objective change did occur, the changes were often modest. (1) When there is visible change, the user should avoid wearing the hearing aids until the change has completely cleared up. Buffing any bumps on the earmold which might have caused the irritation will help against recurrence. If there is not an obvious issue with the earmold or if buffing does not help, mark the point on the earmold that causes the irritation and send it to the manufacture for a remake. The manufacturer will be able to make a new earmold smoother in this area or make the earmold a bit smaller. If the new earmold still causes problems, it is time to take a new ear impression with a different technique (i.e. open jaw vs. closed jaw).

Allergy or dermatitis in reaction to earmold materials is less common but it happens, especially for earmolds made from acrylic or epoxy resin.  Several acrylics, including polyethylene glycol dimethacrylate, 2-hydroxyethyl methacrylate, methyl methacrylate, triethyleneglycol dimethacrylate, and urethane dimethacrylate have been reported to cause contact dermatitis in the ear.^2,3,4 The reaction is often caused by incomplete curing of the monomers. Heat (boiling the ear mold in saline) will increase polymerization and reduce the amount of residual monomer, thus alleviating the problem. Earmolds made from silicone can solve most of the allergy cases. Another option is a gold-plated earmold. Dermatitis and allergic reactions often resolve after discontinued wearing of the hearing aid; if it persists, referral to a dermatologist is recommended.

Moisture in the ear can be tricky. In order to get rid of the moisture, the vent needs to be large, but for severe to profound hearing loss, the vent needs to be small to prevent feedback. The patient should keep their ears clean and visit health professionals to get their ear canals cleaned regularly. Extra wax in the ear will trap more moisture and it takes longer to dry the ear.  The hearing aids should be cleaned and put in a hearing aid dryer during the night.

Besides what is discussed above, dry skin can cause itching for any hearing aid fittings. Dry skin tends to peel or crack and is extremely sensitive to irritations. Scratching will further damage the skin and make the itching worse. Also, avoid using alcohol to clean the ear. A few drops of olive oil may help keep the ear canal skin from excessive dryness and also protect it from water (however, do not put oil in the ear for RIE or custom style hearing aids as the oil may damage the receiver). Commercial products like Eargene, Otoease and Miracell can also be used.

Conclusion

Itching due to wearing hearing aids is common, but it can be treated or alleviated. Make sure the patient gets the best physical fit; keep both ears and hearing aids clean and dry; use lubricant or moisturizer if needed, switch to non-allergenic materials if allergic reactions occur, and refer to an ENT or dermatologist when necessary.

References

1. Itching in the external ear--a side effect of ear plugs. Madsen EF, Larsen J, Flink PO. Ugeskr Laeger, 1991 Jul 22, Vol. 153. 2125-8..

2. Hearing aid dermatitis. Marshall M, Guill A, Odom RB. Arch Dermatol, 1978 Jul;114(7):1050-1.

3. Allergic contact dermatitis from hearing aid materials. Sood A, Taylor JS. Dermatitis, 2004 Mar;15(1):48-50.

4. Allergic contact dermatitis from the earmolds of hearing aids. Meding B, Ringdahl A. Ear Hear, 1992 Apr;13(2):122-4.