Accessory Tragi: Its Causes, Diagnosis and Treatment

What Is Accessory Tragi?

Accessory tragus or tragi is an uncommon congenital (genetic) disorder that appears as an elevated nodule or papules in front of the ears due to developmental defects in the first branchial arch during the sixth week of pregnancy. It is a developmental structural defect and was first reported by Birkett in 1858. Accessory tragi or ears can appear as single or multiple nodules or papules. It can appear on one or both sides of the ears. The nodules are usually benign (non-cancerous) and asymptomatic (do not present any symptoms). Accessory tragi can occur individually due to developmental deformity or in combination with other congenital syndromes.

What Is the Prevalence of Accessory Tragi?

The prevalence of accessory tragus is around 0.1 to 0.3 percent among all newborns.

What Is the Incidence of Accessory Tragi?

• The incidence of the accessory tragus is 5 in 1000 births.

• It affects both males and females equally.

• The incidence of single accessory tragi or ears is around 0.2 percent, and it is bilateral in 0.01 percent of cases.

How Does the Formation of Auricles (Ears) Occur?

Ears or auricles are formed during embryonic development in the fifth or sixth week of intrauterine life. Ears are formed by merging six mesenchymal tissues known as “ hillocks of his,” out of which three mesenchymal tissues are derived from the mandibular arch (the first branchial arch), and the remaining three are derived from the hyoid arch (the second branchial arch).

What Are the Causes of Accessory Tragi?

• The accessory tragus is a developmental deformity associated with the first and second branchial arch (responsible for the development of auricles or ears) that occurs in the sixth week of intrauterine life during embryonic development.

• It occurs due to partial or complete failure of the fusion of “ hillocks of his” (formed by mesenchymal tissue).

• It also occurs associated with congenital (genetic) syndromes like Townes-Brocks, Treacher-Collins syndrome, and Goldenhar syndrome.

How Do the Accessory Tragi Appear Clinically?

The accessory tragus or ears appears as:

• A small nodule or papule in front of the ears.

• Single or multiple nodules may be present.

• One or both ears may be involved.

• Nodules appear as normal skin color.

• Nodules can be soft or hard on palpation.

• Nodules are either directly attached to the base of the skin (sessile) or may be attached by a stalk (pedunculated).

• Nodules are painless or non-tender on palpation.

How to Diagnose Accessory Tragi?

Various methods help in the diagnosis of accessory ears or tragi. Some of them are as follows:

• History and Clinical Examination: A detailed history of the patient for any similar disorder in the family is recorded. The clinical examination of the ears, neck, and face is done by an ENT (ear, nose, and throat) specialist to check for any nodules or papules. Complete clinical examination of the ear, face, and neck is mandatory to rule out the diagnosis in cases associated with congenital syndromes like Goldenhar syndrome.

• Computed Tomography (CT) Scan: Computed tomography scans of the temporal bone help rule out the ears' deformities. A CT scan combines a sequence of X-ray images collected from various angles around the body and utilizes computer processing to produce cross-sectional pictures (slices) of the bone, blood arteries, and tissue within the body.

• Tissue Biopsy: A tissue sample is collected and sent to the laboratory to rule out the diagnosis of the accessory tragus with other skin diseases.

• Renal Ultrasound: Patients are referred to a nephrologist (kidney specialist) to evaluate their renal profile. Ultrasound of the kidney is crucial as, in most cases, the accessory tragus is associated with kidney abnormalities.

• Echocardiogram: Patients are referred to a cardiologist (heart specialist) to rule out any cardiac (heart) anomalies, as in many cases, patients with accessory tragus have cardiac abnormalities.

• Pure Tone Audiometry Test: It is done to evaluate the severity and intensity of hearing loss in patients.

• Auditory Screening: Auditory screening or hearing test is recommended for all newborns using the auditory brainstem response (ABR) test. Soft earplugs are placed in the infant's ears along with the sensors on the head and neck, and the response from the sound is recorded.

• Prenatal Screening: It can be done to rule out any structural defects associated with the ears, like accessory tragi.

• Histological Test: Accessory tragi can be diagnosed based on their histological features, like a thin stratum corneum (skin layer) along with abnormal or irregular placement of hair follicles with sebaceous glands (glands on the skin).

What Is the Treatment of Accessory Tragi?

The following methods do the treatment of accessory tragi:

• Surgical Excision: It is recommended for patients who are more concerned about cosmetics or the appearance of accessory tragi. Surgical removal of the accessory tragus is done by giving a wedge shape cut through the surgical blade. A flap (skin tissue) is then used to cover the surgical site.

• Punch Excision: It is one of the procedures to remove the accessory tragus. This technique has shown good cosmetic results.

• Shave Excision: It is one of the surgical techniques to remove accessory tragi. The drawback of this technique is that it leaves exposed pieces of excised cartilage, which causes a delay in wound healing and can result in complications like chondrodermatitis.

• Genetic Counseling: Genetic counseling is recommended for patients and their families.

What Are the Recent Researches Conducted on the Management of Accessory Tragi?

According to current research, the use of titanium clips for excision (removal) of the accessory tragus or supernumerary ears during the early neonatal period has been suggested by the research doctors' team for the management of the accessory tragi.

Conclusion

Accessory tragi is an uncommon inborn deformity that presents with a raised papule or nodule in the front of the ears, which can be single or multiple. Early diagnosis and auditory screening of all newborns are mandatory for the management of the symptoms. Prompt diagnosis helps to identify whether the accessory tragus is due to an individual embryological defect or co-existing with other congenital syndromes.