Dear Sir,

We read with interest the article by Ors [1] on prominent ear deformities and its recurrence rate. This article gives us the opportunity to better understand the effectiveness of nonsurgical options for the treatment of ear anomalies in young patients (5–14 years).

The current COVID-19 pandemic has imposed the worldwide use of masks in addition to social distancing. The use of masks applies to everyone, even children, certainly if over the age of 5–6 years.

The masks distributed to the population by government bodies are of various types, both as regards to their shape and the systems for fastening them to the head, but, basically, they are divided into 4 large categories: masks with elastic (ear loops), strips of fabric with lateral slits (side cuts at the ears), with tapes, single cervical band.

Small children are rarely made to wear the masks with tapes, due to the difficulty in positioning and tying the tapes.

The “single band” masks that wrap around the neck have the drawback of sliding downwards and, therefore, not keeping the nose covered; furthermore, if used during the summer season, they tend to produce a humid microenvironment that favours the development of dermatitis and eczema.

Consequently, the masks most used for children are the first two types (Fig. 1a and b).

Fig. 1
figure 1

The masks most used for children. a Surgical mask with ear loops. b Mask with side cuts at the ears

Full size image

Many adults (health care workers and others) complain about discomfort associated with ear loops, due to the continuous pressure of the elastic behind the ear. Several methods have been proposed to overcome this problem: from the use of hairpins to hang the elastic bands from the forehead to the use of various types of bands that pass behind the back of the neck and to which the loops of the mask are attached. However, these methods used by adults are not used by children, resulting in constant pressure of the elastic on the skin of the posterior portion of the auricle.

All bodies subject to the action of a force undergo deformation, which depends not only on the intensity of the force applied, but also on the nature of the body itself. In general, deformations can be of two types: elastic, which disappear when the force is no longer applied, and non-elastic, which remain even after applying the force. Cartilage has memory thanks to the presence of elastic fibres; although this allows it to return to its initial condition when deformed, if the stimulus persists, it can lead to permanent changes in its conformation.

This principle has been used for many years for the conservative correction of protruding ears [1, 2]. Obviously, in order to use these non-surgical correction techniques (e.g. bands, patches, ear splint therapy) with benefit, the development of the various components of the ear must not be completed. This can happen if applied in children who are less than 8–10 years old, because after that age the cranial volume, with its appendages, almost completely reaches total growth [3]. The literature reports important successes in the treatment of protruding ears with conservative methods, with a success rate that shows a decline from 91% in infants to 33% in 9-year-old children [1, 2, 4].

The main advantage of this treatment is that it keeps the splint in position for a long time, so that it can exert constant pressure on the growing cartilage, changing it into the desired shape.

The success of these conservative methods confirms that a constant pressure maintained for a long time on the cartilage of the ear of growing children can change the shape and increase the cephaloauricular angle of the outer auricle.

Griffin et al. have demonstrated that the cartilage of the auricle has a homogeneous structure, although the concha has a greater resistance to deformation than the helix [5]. This resistance is comparable to that of nasal cartilage (about 200 times lower than the resistance of Medpor prostheses used for ear reconstruction). The concha had a greater rate of loading than the antihelix when taking into consideration the anatomical structure of the cartilages. One reason for this difference may be that the concha is a curved structure, which can support compressive loads [5]. Therefore, if a constant elastic force were applied at the level of the concha, it would be less harmful than if applied at the antihelix level.

It is well known that the pressure of the elastic on the skin of the posterior concha of the auricle for a long time causes pain and erythema, due to the continuous rubbing of the elastic on the skin in the same position. This has led some users to apply silicone rear ear supports that decrease decubitus, but increase the distance of the auricle from the mastoid region. Others, on the other hand, prefer to change the position of the elastic by moving it more towards the antihelix than the mastoid region, thus applying an elastic force in an area where the cartilage has less resistance, with a consequent increase in the cephaloauricular angle of the outer auricle.

Therefore, the use of surgical masks with ear loops in growing children for many hours a day not only leads to intolerance and decubitus of the retroauricular skin (as for adults), but can also influence the correct growth and angulation of the outer ear with the consequent increase in the incidence of protrusion of the outer auricle (Fig. 2a and b).

Fig. 2
figure 2

a Modification of the cephaloauricular angle following the placement of a surgical mask with ear loops (b) and band mask with side slits (c) in a 6-year-old girl

Full size image

One alternative to the surgical mask is the earmuffs mask (in which the ears are completely wrapped, held in place by an elastic band at the back of the ear) or the band mask with lateral slits at the ears: also these models, due to their conformation, tend to create a constant pressure on the antihelix, increasing the auriculocephalic angle (Fig. 2c).

Many scientific societies of paediatrics and pedagogy have raised doubts about the risks that this situation of forced constriction by Covid-19 can cause on the normal psychophysical development of children; however, it has never been pointed out how the use of surgical masks with ear loops can be harmful to the correct development of the auricle by permanently modifying the cartilage of the concha in growing children.

We are confident that highlighting this potential complication to those involved in the procurement of masks will stimulate the search for alternative solutions, while maintaining the possibility of legitimate prevention of the potential spread of the virus.