Preauricular Sinuses 

Updated: Jan 27, 2020
Author: Jeffrey Weinberg, MD; Chief Editor: William D James, MD 

Overview

Background

Preauricular sinuses are common congenital malformations first described by Heusinger in 1864.[1] Preauricular sinuses are frequently noted on routine physical examination as small dells adjacent to the external ear, usually at the anterior margin of the ascending limb of the helix. However, preauricular sinuses have been reported to occur along the lateral surface of the helicine crus and the superior posterior margin of the helix, the tragus, or the lobule. Anatomically, preauricular sinuses are lateral and superior to the facial nerve and the parotid gland.

Preauricular sinuses are inherited in an incomplete autosomal dominant pattern, with reduced penetrance and variable power of expression. They can arise spontaneously. The sinus may be bilateral in 25-50% of cases, and bilateral sinuses are more likely to be hereditary.[2] In unilateral cases, the left side is more commonly affected.

Also see the related article Preauricular Cysts, Pits, and Fissures.

Pathophysiology

During embryogenesis, the auricle arises from the first and second branchial arches during the sixth week of gestation. Branchial arches are mesodermal structures covered by ectoderm and lined with endoderm. These arches are separated from each other by ectodermal branchial clefts externally and by endodermal pharyngeal pouches internally. The first and second branchial arches each give rise to 3 hillocks; these structures are called the hillocks of His. Three hillocks arise from the caudal border of the first branchial arch, and 3 arise from the cephalic border of the second branchial arch. These hillocks should unite during the next few weeks of embryogenesis. Preauricular sinuses are thought to occur as a result of incomplete fusion of these hillocks.

Preauricular sinuses are usually narrow, they vary in length (usually they are short), and their orifices are usually minute. They may arborize and follow a tortuous course in the immediate vicinity of the external ear. The preauricular sinuses are usually found lateral, superior, and posterior to the facial nerve and the parotid gland. In almost all cases, the duct connects to the perichondrium of the auricular cartilage. They can extend into the parotid gland.

Congenital periauricular fistulas may be seen as variations of preauricular sinuses.[3]

Etiology

Preauricular sinuses are malformations that result from incomplete fusion of 2 of the 6 hillocks that arise from the first and second branchial arches.

Epidemiology

Frequency

United States

In one study, the incidence of preauricular sinuses in the United States is estimated to be 0-0.9% and the incidence in New York State is estimated to be 0.23%.

International

In Taiwan, the incidence of preauricular sinuses is estimated to be 1.6-2.5%; in Scotland, 0.06%; and in Hungary, 0.47%. In some parts of Asia and Africa, the incidence of preauricular sinuses is estimated to be 4-10%. One study in Kenya found preauricular sinuses to be the most common congenital oral and craniofacial anomalies, with a rate of 4.3 cases per 1000 persons.[4]

Race

The incidence of preauricular sinuses in whites is 0.0-0.6%, and the incidence of preauricular sinuses in African Americans and Asians is 1-10%.

Sex

Both men and women are affected equally by preauricular sinuses.

Age

Preauricular sinuses arise in the antenatal period and are usually present at birth, but they can become apparent later in life.

Prognosis

Preauricular sinuses generally have a good prognosis. Preauricular sinuses have no associated mortality.

Morbidity associated with preauricular sinuses includes recurrent infections at the site, ulceration, scarring, pyoderma, and facial cellulitis. Specifically, the following conditions may occur: abscesses at and anterior to the involved ear, chronic and recurrent drainage from sinus orifices, malar ulceration, otitis externa, and unilateral facial cellulitis.

Surgical treatment has its own associated morbidity, with the possibility of postoperative recurrence.

 

Presentation

History

Most people with preauricular sinuses are asymptomatic. Only one third of persons are aware of their malformations. In one study of 31 patients, once the lesions became apparent, about 9.2 years (on average) passed before they sought medical care.

Some patients with preauricular sinuses present with chronic intermittent drainage of purulent material from the opening. Draining sinuses are prone to infection. Once infected, these sinuses rarely remain asymptomatic, often developing recurrent acute exacerbations.

Patients with preauricular sinuses may present with facial cellulitis or ulcerations located anterior to the ear. These ulcerations are often treated without recognition of the primary source, and the preauricular sinus remains unnoticed.

Subsequent to infection, a patient with preauricular sinuses may develop scarring and disfigurement.

Infants of diabetic mothers are at increased risk for the oculo-auriculo-vertebral sequence, which includes sinuses.[5]

Physical Examination

The preauricular sinus usually presents as a small dell adjacent to the anterior margin of the ascending limb of the helix, as noted in the image below.

Small dell adjacent to the ear demonstrates the pr Small dell adjacent to the ear demonstrates the preauricular sinus.

Unless they are actively infected or have previously been infected with subsequent scarring, they are only small openings in the external ear. If associated conditions are present, one might see external ear anomalies, such as flop ears. Physical examination may reveal associated branchiogenic fistulas and/or hearing loss.[6]

In 2006, Saltzmann and Lissner[7] reported an unusual case of familial punctal atresia with apparent genetic linkage to bilateral preauricular sinuses that lacked any comorbid syndromic features, which is usually not the case.

Choi et al,[8] in 2007, noted that what is termed the preauricular sinus can occur in the postauricular area. Sinuses occurring in the postauricular areas seem to have a lower rate of recurrence after surgery (0%) than those in the preauricular area (2.2%).

Associated conditions

Conditions associated with preauricular sinuses include subcondylar impaction of a third molar, renal malformations,[9] hearing loss, branchiogenic fistulas, commissural lip pits (3.8% of patients with these have preauricular sinuses), and external ear anomalies; however, these conditions rarely occur.

Cleft palate, spina bifida, imperforate anus, renal hypoplasia or renal agenesis, reduplication of the duodenum, undescended testes, and umbilical hernias are reported associations.

Preauricular sinuses are involved in the following syndromes: Treacher Collins syndrome; branchio-oto-renal (BOR) syndrome; hemifacial microsomia syndrome; a syndrome consisting of facial steatocystoma multiplex associated with pilar cysts and bilateral preauricular sinuses; and a syndrome that includes preauricular sinuses, conductive deafness, commissural lip pits, and external ear abnormalities. BOR syndrome consists of conductive, sensorineural, or mixed hearing loss; preauricular pits; structural defects of the outer, middle, or inner ear; renal anomalies; lateral cervical fistulas, cysts, or sinuses; and/or nasolacrimal duct stenosis or fistulas. Hemifacial microsomia syndrome can include preauricular sinuses, facial nerve palsy, sensorineural hearing loss, microtia or anotia, cervical appendages containing cartilage, and other defects.[10]

A report and review in 2012 described a 6-year-old girl with off and on left and right discharging neck swellings.[11] MRI documented branchial cleft fistulae on the right and left sides. She had removal of the brachial fistula and a tonsillectomy and recovered fully.

Associated facial pathology

Preauricular sinuses can be associated with facial pathology. In one case, a preauricular sinus associated with a congenital cholesteatoma resulted in a facial palsy by impinging on the facial nerves.

Wound infections after rhytidectomy have also been associated.

Calculi can develop in the preauricular sinuses, resulting in infection.

Other findings

A novel autosomal dominant syndrome consisting of hypertelorism, punctal pits, preauricular sinus, and deafness (HPPD) located on 14q31 has been noted.[12]

Other constellations of conditions that occur with preauricular sinuses include natal teeth, kidney stones, and atopic dermatitis.[13]

Jimena et al describe a female aged 6 years with left- and right-draining anterior neck puncta, moderately severe bilateral hearing loss and a preauricular sinus, and moderately severe bilateral hearing loss with concomitant first and bilateral second branchial fistulas concurrent with simultaneous nonfamilial branchio-otic syndrome. The study found this was the third such case in the literature.[14]

Congenital periauricular fistulas may be seen as variations of preauricular sinuses.[3]

The co-incidence of branchial arch anomalies (branchial cysts, branchial fistulas), renal anomalies, and hearing loss together can be termed the Melnick-Fraser syndrome, also described as branchio-oto-renal (BOR) syndrome. A case from Pakistan in a female neonate who presented with profound deafness, branchial sinuses, preauricular pits, and renal hypoplasia was noted in 2014 by Jalil et al.[15]

 

DDx

 

Workup

Laboratory Studies

If exudate from the sinus is present, culturing should be performed so that antibiotic therapy tailored to the offending pathogen can be instituted. In 2002, Martin-Granizo et al[16] suggested that initial fistula probing serves as a surgical guide and further methylene blue infection helps to avoid leaving viable squamous epithelial remnants.

Imaging Studies

Ultrasonography readily depicts preauricular sinuses and demonstrates their relationship to the superficial temporal artery, the anterior crus of the helix, and the tragus.

In patients with isolated preauricular sinuses or tags, ultrasound should not be done as a matter of course to rule out urinary tract of kidney anomalies in children without other a high index of clinical suspicion.[17]

Histologic Findings

Upon gross examination, the preauricular sinuses are seen to consist of tubular structures of simple or arborized patterns having walls, which may be thin and glistening or white and thickened. The sinus tract may arborize and can be tortuous, and the lumen is filled with debris. The preauricular sinuses are often full of keratin and are surrounded by dense connective tissue.

Microscopically, the duct of the sinus is lined with stratified squamous epithelium and contains many cysts along its tract. The connective tissue surrounding the duct may contain hair follicles; sebaceous and sweat glands; and inflammatory tissue, such as lymphocytes, plasma cells, and polymorphonuclear leukocytes.

 

Treatment

Medical Care

In one large study, 52% of patients had inflammation of their sinuses, 34% had their sinus abscesses drained, and 18% of sinuses were infected. Infectious agents identified included Staphylococcus epidermidis (31%), Staphylococcus aureus (31%), Streptococcus viridans (15%), Peptococcus species (15%), and Proteus species (8%). Once a patient acquires infection of the sinus, he or she must receive systemic antibiotics. If an abscess is present, it must be incised and drained, and the exudate should be sent for Gram staining and culturing to ensure proper antibiotic coverage.

Surgical Care

Once infection occurs, the likelihood of recurrent acute exacerbations is high, and the sinus tract should be surgically removed.[2] Surgery should take place once the infection has been treated with antibiotics and the inflammation has had time to subside. Controversy regarding indications for surgery exists. Some believe that the sinus tract should be surgically extirpated in patients who are asymptomatic because the onset of symptoms and subsequent infection cause scarring, which may lead to incomplete removal of the sinus tract and postoperative recurrences. The recurrence rate after surgery is 13-42% in smaller studies and 21% in one large study.

Most postoperative recurrences occur because of incomplete removal of the sinus tract. One way to prevent incomplete removal is to properly delineate the tract during surgery. Some surgeons cannulate the orifice and inject methylene blue dye into the tract 3 days prior to surgery under sterile conditions. The opening is then closed with a purse-string suture. This technique distends the tract and its extensions by its own secretion stained with methylene blue.

During surgery, some surgeons use either a probe or an injection of methylene blue dye for cannulation of the orifice. The most successful method is to use both modalities to delineate the entire tract. One report described 141 successful, infection-free results in which a gentian violet – soaked Cottonoid, which has antibacterial effects, was used instead of methylene blue dye.[18]

Other surgical techniques have been studied. The standard technique for extirpation of the sinus tract involves an incision around the sinus and subsequent dissection of the tract to the cyst near the helix. A supposedly more successful technique is the supra-auricular approach, which unlike the former technique, does not allow for difficulties in properly identifying the entire tract.[19] The supra-auricular approach extends the incision postauricularly. Once the temporalis fascia is identified, dissection of the tract begins. A portion of the auricular cartilage, which is attached to the tract, is also removed, decreasing the incidence of recurrence to 5%. Leopardi et al report that they prefer the supra-auricular approach for the surgical treatment of recurring preauricular sinus.[20]

Tan et al[21] reported the most current data in 2005, which suggested that the definitive surgical intervention that promises the best outcome is wide local excision of the sinus, not simple sinectomy. To minimize the risk of recurrence, Tan et al[21] suggest using magnification and intraoperatively opening the sinus and then following from the inside of the sinus to the outside branching tracts of the sinus.

Similarly, Chang and Wu[22] stated in 2005 that the use of an operating microscope can enhance the effectiveness of surgery to remove remnants and help prevent recurrence of a preauricular cyst.

Baatenburg de Jong reports on an "inside-out" technique, which was deemed superior to the classic repair technique, with fewer recurrences, in a small, single-institution study.[23]

Yeo et al[24] found that in a case series of 191 patients with preauricular sinuses (206 surgeries), the recurrence rate following surgery was 4.9%, with surgery under local anesthesia being a risk factor for recurrence (P = .009). Additionally, the cases that involved local infiltrative anesthesia had an increased rate of recurrence compared with surgery performed with the patient under general anesthesia (odds ratio, 6.875).

In a 2007 study from a referral center in Malaya, Tang et al[25] reviewed cases of 71 patients with 73 preauricular sinuses. They found an overall recurrence rate of 14.1% and that 16% of sinuses required drainage of an abscess prior to definitive surgery. Additionally, preauricular sinuses with a previous history of infection or those actively infected during the definitive surgery seemed to be associated with a higher tendency for recurrence. Surgical demonstration of the sinus tract by probing with lacrimal probes or sinus probes, followed by injection of methylene blue, reduces the recurrence rate. Some have advocated a minimal supra-auricular approach without a surgical drain for removal of preauricular sinuses.[26]

Dickson et al found that methylene blue was a safe and useful means of demarcation of preauricular sinuses and branchial sinuses and fistulae in a series of 20 children with preauricular sinuses and 11 with branchial sinuses and fistulae, allowing for smaller incisions and minimal dissections.[27]

In 2010, Bajwa and Kumar reported on radiofrequency thermal ablation versus cold steel” excision for supra-auricular excision of preauricular sinuses. They concluded that radiofrequency-assisted local wide excision appeared to be superior to cold steel excision because the former offered better perioperative visualization, with minimal bleeding and easier dissection. Additionally, they reported that radiofrequency thermal ablation was associated with a lower recurrence rate.[28]

In a 2009 study of the histologic relationship of preauricular sinuses to auricular cartilage, Dunham et al found that sinocartilaginous distances may suggest it can be challenging to dissect most sinus tracts from the cartilage. Thus, the routine removal of a minimal portion of auricular cartilage in combination with the sinus tract can provide a more thorough excision and may stop recurrence.[29]

A group in Singapore found that microscope guidance using probe guidance with methylene blue yields a lower recurrence rate than simply using methylene blue with probe guidance.[30]

A report form Chowdary et al advocates use of magnification during surgery. The surgery involves a wide surgical technique accompanied with a postextended auricular incision through a supra-auricular approach (successful at 8 y follow-up).[31]

The state-of-the-art of surgery on preauricular sinuses has not advanced in 2015, and surgical treatment options reported previously to 2015 continue to be used.[32]

If the preauricular sinus recurs, it should be fully removed.

Consultations

Consult plastic surgeons or otolaryngologists for surgical treatment.

Complications

Patients may develop infection of the tract with abscess formation. Coatesworth et al described successful management of preauricular sinus abscess that allows drainage of pus with minimal or no disturbance of the sinus.[33]

Infections and ulcerations may occur at a site distant from the opening.

Postoperative recurrence is a complication of preauricular sinus tract extirpation. Several factors contribute to recurrence after surgery, as follows:

  • Previous attempt at surgical removal

  • Surgery under local anesthesia

  • Incomplete removal of the sinus tract

  • Active infection at the time of surgery

  • Drainage of an abscess prior to surgery

  • Poor delineation of the entire sinus tract during surgery

  • Failing to remove the auricular cartilage at the base of the sinus

  • Failing to identify the facial nerve because it lies close to the sinus

Most recurrences occur during the early postoperative period, within 1 month of the procedure. Recurrences should be suspected when discharge from the sinus tract opening persists. The overall incidence of recurrence varies among different studies and ranges from 5-42%.

Winkler et al noted a scalp arteriovenous malformation spontaneously hemorrhaging into a preauricular sinus; it was successfully treated with intravascular embolization and surgical ligation.[34]

Prevention

If the preauricular sinus becomes repeatedly infected, it can be surgically removed.

Long-Term Monitoring

If a preauricular sinus is repeatedly infected and the patient does not want surgery, its contents can be cultured and proper antibiotics to cover the pathogens can be given.