AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Preauricular sinuses are common congenital malformations first described by Heusinger in 1864. They 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, they 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, they 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 like to be hereditary. In unilateral cases, the left side is more commonly affected.

A few resources that may be helpful include the eMedicine article Preauricular Cysts, Pits, and Fissures, the Medscape Otitis Media Resource Center, and the Medscape CME courses Diagnostic Methods to Treat Ear Pain in Primary Care Setting and Antibiotics Not Recommended to Prevent Middle Ear Effusion in Children.

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.

Frequency

United States

In one study, the incidence 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 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 is estimated to be 4-10%.

Mortality/Morbidity

• Preauricular sinuses have no associated mortality.
• Morbidity 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.

Race

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

Sex

Both men and women are affected equally.

Age

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

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

History

• Most people with this malformation 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 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 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 may develop scarring and disfigurement.
• Infants of diabetic mothers are at increased risk for the oculo-auriculo-vertebral sequence, which includes sinuses.¹

Physical

The preauricular sinus usually presents as a small dell adjacent to the anterior margin of the ascending limb of the helix. 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.
 
In 2006, Saltzmann and Lissner² 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,³ 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, 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.
• Associated facial pathology
• • Preauricular sinuses can be associated with facial pathology. In one case, a preauricular sinus associated with a congential 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.

Causes

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

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Branchial cleft sinus
Cysts forming from the first pharyngeal pouch abscess
Ulceration on the face

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab 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 al⁴ 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.

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

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

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. 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.

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. 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%.

Tan et al⁵ 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 al⁵ 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 Wu⁶ 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.

Yeo et al⁷ 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 al⁸ 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.

Consultations

Consult plastic surgeons or otolaryngologists for surgical treatment.

FOLLOW-UP

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Inpatient Care

• If the sinus reoccurs, it should be fully removed.

Further Outpatient Care

• 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.

In/Out Patient Meds

• Usually, no medications must be given, but if infection occurs, antibiotics can be given. The contents of the sinus should be cultured before antibiotics are prescribed.

Deterrence/Prevention

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

Complications

• Patients may develop infection of the tract with abscess formation.
• 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%.

Prognosis

• Preauricular sinuses generally have a good prognosis.

MISCELLANEOUS

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Failure to recognize that a preauricular sinus can cause facial abscess and ulceration
• Failure to recognize that a preauricular sinus can recur after surgery
• Failure to recognize that a preauricular sinus can be associated with congenital deafness
• Failure to recognize that a preauricular sinus can result in facial palsy by impinging on facial nerves
• Failure to recognize that a preauricular sinus can lead to infection if facial surgery is performed proximal to it
• Failure to consider audiologic or renal evaluation if a preauricular sinus is present
• Failure to identify an infected preauricular sinus and not treating it with proper antibiotics and/or surgery (A preauricular sinus may be confused with a cyst when infected.)

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Small dell adjacent to the ear demonstrates the preauricular sinus.
	View Full Size Image
Media type:  Photo

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Follow-up
• Miscellaneous
• Multimedia
• References

1. Wang R, Martínez-Frías ML, Graham JM Jr. Infants of diabetic mothers are at increased risk for the oculo-auriculo-vertebral sequence: A case-based and case-control approach. J Pediatr. Nov 2002;141(5):611-7. [Medline].
2. Saltzmann RM, Lissner GS. Familial absence of lacrimal puncta associated with preauricular sinuses. J Pediatr Ophthalmol Strabismus. Jul-Aug 2006;43(4):233-5. [Medline].
3. Choi SJ, Choung YH, Park K, Bae J, Park HY. The variant type of preauricular sinus: postauricular sinus. Laryngoscope. Oct 2007;117(10):1798-802. [Medline].
4. Martin-Granizo R, Pérez-Herrero MC, Sánchez-Cuéllar A. Methylene blue staining and probing for fistula resection: application in a case of bilateral congenital preauricular fistulas. Int J Oral Maxillofac Surg. Aug 2002;31(4):439-41. [Medline].
5. Tan T, Constantinides H, Mitchell TE. The preauricular sinus: A review of its aetiology, clinical presentation and management. Int J Pediatr Otorhinolaryngol. Nov 2005;69(11):1469-74. [Medline].
6. Chang PH, Wu CM. An insidious preauricular sinus presenting as an infected postauricular cyst. Int J Clin Pract. Mar 2005;59(3):370-2. [Medline].
7. Yeo SW, Jun BC, Park SN, Lee JH, Song CE, Chang KH, et al. The preauricular sinus: factors contributing to recurrence after surgery. Am J Otolaryngol. Nov-Dec 2006;27(6):396-400. [Medline].
8. Tang IP, Shashinder S, Kuljit S, Gopala KG. Outcome of patients presenting with preauricular sinus in a tertiary centre--a five year experience. Med J Malaysia. Mar 2007;62(1):53-5. [Medline].
9. Baatenburg de Jong RJ. A new surgical technique for treatment of preauricular sinus. Surgery. May 2005;137(5):567-70. [Medline].
10. Chami RG, Apesos J. Treatment of asymptomatic preauricular sinuses: challenging conventional wisdom. Ann Plast Surg. Nov 1989;23(5):406-11. [Medline].
11. Coatesworth AP, Patmore H, Jose J. Management of an infected preauricular sinus, using a lacrimal probe. J Laryngol Otol. Dec 2003;117(12):983-4. [Medline].
12. Currie AR, King WW, Vlantis AC, Li AK. Pitfalls in the management of preauricular sinuses. Br J Surg. Dec 1996;83(12):1722-4. [Medline].
13. Lam HC, Soo G, Wormald PJ, Van Hasselt CA. Excision of the preauricular sinus: a comparison of two surgical techniques. Laryngoscope. Feb 2001;111(2):317-9. [Medline].
14. Leung AK, Robson WL. Association of preauricular sinuses and renal anomalies. Urology. Sep 1992;40(3):259-61. [Medline].
15. O'Mara W, Guarisco L. Management of the preauricular sinus. J La State Med Soc. Sep 1999;151(9):447-50. [Medline].
16. Scheinfeld NS, Silverberg NB, Weinberg JM, Nozad V. The preauricular sinus: a review of its clinical presentation, treatment, and associations. Pediatr Dermatol. May-Jun 2004;21(3):191-6. [Medline].

Article Last Updated: Mar 18, 2008