You may have noticed that there are some people who have a very small, additional hole in their ear where the top of the ear cartilage meets their face. And it isn’t due to an old piercing or injury, this is a congenital disorder known as preauricular sinus.
How Common is Preauricular Sinus?
Just 0.1 percent of the population have it in the United States and only 0.9 percent in the UK. There are as many as 4 to 10 percent individuals with it in Asia as well as in parts of Africa, according to a study performed by medical scientists at Chung-Ang University, which was published online in 2012 in the Korean Journal of Audiology. In South Korea, that figure could be as high as 5 percent and it is most common in people of African or Asian descent.
Is the Disorder Harmful?
Even though it is harmless it can be susceptible to infection. It is caused by the first and second pharyngeal arches. This is a structure that is found in all vertebrates that occurs during the embryonic development. In mammals, they go on to form the structures of the head and neck, but in fish, they also help develop into their gills.
Why Is It There?
It is this odd connection that led Neil Shubin, who is an evolutionary biologist, to speculate that the holes could be an evolutionary remnant of fish gills, according to Business Insider. Of course, that’s currently a theory that hasn’t been scientifically tested at this time. But, when you consider the fact that we still have tailbones, goosebumps, and appendixes from our evolutionary ancestors, it is certainly not impossible.
According to the study A Case of Bilateral Postauricular Sinuses that was posted in the Korean Journal of Audiology…,
Preauricular sinuses are common congenital malformations that usually occur at the anterior margin of the ascending limb of the helix. There are rare cases in which the location of the preauricular sinus is posterior to the tragus, and the direction of the sinus tract is toward the posterior. This variant type of preauricular sinus is called, ‘postauricular sinus’. Postauricular sinus is uncommon. Thus, diagnosis and treatment may be delayed due to its location of its opening and atypical clinical symptoms. Typical treatment is a single stage operation through bidirectional skin incision. However, we found out that according to the length and invasion depth of the sinus tract, there was an option between unidirectional and bidirectional skin incisions that we may choose from.
Possible Issues with Preauricular Sinuses
In the case report performed by Hong Jun Kim, Jae Heon Lee, Hyun Sang Cho and In Seok Moon, A 27-year old male visited the department of Otorhinolaryngology Head and Neck Surgery at Chung-Ang University Hospital complaining of painful swelling, erythema and tenderness on the left ear. He had a history of incision and drainage twice in the right ear and once in the left due to similar symptoms in the past.
Upon physical examination, there was swelling and tenderness in the left retroauricular area. Plus, in the center of the crus of helix, there was a small opening showing pus drainage. There was no swelling or tenderness on the right auricle, but there was a small opening in the center of the crus of helix.
Since there were sinus openings on but crus of helix manifestations of retroauricular area swelling and history of recurrent infection, the patient was prediagnosed as the bilateral variant type of preauricular sinus, also known as “postauricular sinus.”
Surgery was performed after one week of antibiotics were administered and the acute inflammation was relieved. Fistulography was performed to identify the location of the sinus and the length of the sinus tract, and there were a 0.5 cm 0.1 cm sized sinus tract for each right and left side, heading towards the posterior middle portion of the auricles.
The Surgical Procedure & Recovery
During the surgery, local anesthesia was performed around the left sinus opening and retroauricular area. Then, gentian violet was injected into the sinus tract for dyeing. Perpendicular-oval shaped incision, including the opening of the sinus, was done and excision was preceded by identifying the dyed sinus.
The direction of the sinus tract could be identified using a lacrimal probe. The sinus was observed to penetrate the cartilage of the crus of helix and directed toward posterior part of the auricle as in the sinus form. Retroauricular incision was performed for complete removal of the sinus, and cartilage of the crus of helix was also removed.
Then, a drain was inserted and primary closure was performed. Same procedure was performed for the right side, but upon the insertion of the probe, the length of the sinus was small, and it was observed that it invaded to invade only a portion of cartilage of the crus of helix. Therefore, only an incision around the sinus opening was used completely to remove the sinus.
The patient was discharged without complications and total stitch off was done 7 days after the surgery. Histopathologic studies diagnosis was confirmed it as preauricular sinus, since the sinus tract lined with chronic inflammatory squamous epithelium, and 12 months after the surgery, the patient is on follow up without complications and signs of recurrence.