Congenital Auricular Fistula

A congenital auricular fistula, also known as a preauricular sinus or pit, is a type of congenital malformation that affects the external ear. It is a small opening or depression in the skin near the front of the ear that can extend into the underlying tissues. Congenital auricular fistulas are present at birth and are believed to be caused by abnormal development of the embryonic tissue that forms the ear.

Definition: A congenital auricular fistula is a type of congenital malformation that affects the external ear and is characterized by a small opening or depression in the skin near the front of the ear that can extend into the underlying tissues.

Epidemiology: Congenital auricular fistulas are relatively common and occur in approximately 1 in every 5,000 to 10,000 live births. They can occur in isolation or as part of a syndrome, and both males and females are equally affected.

Classification: Congenital auricular fistulas can be classified into several different types based on the location, size, and shape of the opening. Some common classifications include:

• Simple fistula: This type of fistula is characterized by a small, circular opening near the front of the ear that does not extend into the underlying tissues.
• Branching fistula: This type of fistula is characterized by a larger opening with multiple branches that extend into the underlying tissues.
• Complex fistula: This type of fistula is characterized by a large opening that extends deep into the underlying tissues and may be associated with other congenital anomalies.

Causes

There are several causes of congenital auricular fistula, including:

1. Congenital malformation: This is the most common cause of auricular fistula and occurs when there is an abnormal development of the ear during embryonic development. This can result in a connection between the external and inner ear.
2. Trauma: Trauma to the head during delivery or after birth can cause a tear in the ear drum, resulting in a fistula.
3. Infection: Infections in the inner ear, such as meningitis or mastoiditis, can cause a fistula to develop.
4. Autoimmune diseases: Autoimmune diseases, such as Wegener’s granulomatosis, can cause inflammation and damage to the inner ear, resulting in a fistula.
5. Tumors: Tumors in the inner ear can cause a fistula to develop.
6. Genetics: Some cases of auricular fistula are inherited and are caused by a genetic mutation.
7. Environmental factors: Exposure to certain chemicals, such as lead or mercury, can cause damage to the inner ear and result in a fistula.
8. Radiation therapy: Radiation therapy to the head and neck area can cause damage to the inner ear and result in a fistula.
9. Ototoxicity: Certain medications, such as aminoglycoside antibiotics, can be toxic to the inner ear and result in a fistula.
10. Infections in utero: Infections in the womb, such as rubella or cytomegalovirus, can cause damage to the inner ear and result in a fistula.
11. Cholesteatoma: A cholesteatoma is a type of skin cyst that can develop in the middle ear. It can cause a fistula to develop if it erodes the ear drum.
12. Eustachian tube dysfunction: The Eustachian tubes connect the middle ear to the back of the throat. If these tubes become blocked or do not function properly, fluid can build up in the middle ear and result in a fistula.
13. Barotrauma: Barotrauma can occur when there is a rapid change in pressure, such as during air travel or scuba diving. This can cause a tear in the ear drum and result in a fistula.
14. Acoustic neuroma: An acoustic neuroma is a type of tumor that grows on the nerve that connects the inner ear to the brain. It can cause a fistula to develop if it grows into the inner ear.
15. Méniere’s disease: Méniere’s disease is a condition that affects the inner ear and can cause hearing loss, vertigo, and tinnitus. It can also cause a fistula to develop.
16. Temporal bone fractures: Fractures to the temporal bone, which surrounds the inner ear, can cause a fistula to develop.
17. Mastoiditis: Mastoiditis is an infection of the mastoid bone, which is located behind the ear. It can cause a fistula to develop if the infection spreads to the inner ear.
18. Chronic otitis media: Chronic otitis media is a persistent inflammation of the middle ear. It can cause a fistula to develop if the ear drum becomes perforated.

Symptoms

It is characterized by an abnormal communication between the external ear and the middle ear or the inner ear. CAF is present at birth and can cause a range of symptoms, depending on its severity and location. In this article, we will discuss common symptoms of CAF.

1. Conductive hearing loss: Conductive hearing loss is the most common symptom of CAF. It occurs when there is a problem with the transmission of sound from the outer ear to the inner ear. This can result in a decreased ability to hear, particularly in the low-frequency range.
2. Drainage from the ear: Drainage from the ear is a common symptom of CAF. This can range from a mild discharge to a more severe, persistent flow of fluid from the ear.
3. Pain or discomfort in the ear: Pain or discomfort in the ear is another common symptom of CAF. This can range from a mild ache to a more severe, persistent pain.
4. Tinnitus: Tinnitus is a ringing or buzzing in the ear that is not caused by an external sound. This can be a symptom of CAF, particularly if the fistula is affecting the inner ear.
5. Vertigo: Vertigo is a sensation of spinning or dizziness that can be caused by a problem with the inner ear. This can be a symptom of CAF, particularly if the fistula is affecting the inner ear.
6. Nausea: Nausea is a feeling of sickness or discomfort in the stomach that can be accompanied by dizziness or vertigo. This can be a symptom of CAF, particularly if the fistula is affecting the inner ear.
7. Vomiting: Vomiting is the forceful discharge of the contents of the stomach through the mouth. This can be a symptom of CAF, particularly if the fistula is affecting the inner ear.
8. Loss of balance: Loss of balance is a common symptom of CAF, particularly if the fistula is affecting the inner ear. This can result in a decreased ability to maintain proper balance and can lead to falls or other accidents.
9. Hearing changes: Hearing changes can occur in individuals with CAF, particularly if the fistula is affecting the middle ear. This can range from a mild decrease in hearing ability to a more severe, permanent loss of hearing.
10. Speech difficulties: Speech difficulties can occur in individuals with CAF, particularly if the fistula is affecting the middle ear. This can result in a decreased ability to understand speech, particularly in noisy environments.
11. Chronic ear infections: Chronic ear infections can be a symptom of CAF, particularly if the fistula is affecting the middle ear. This can result in a persistent, painful infection that can cause hearing loss and other symptoms.
12. Facial nerve weakness: Facial nerve weakness can occur in individuals with CAF, particularly if the fistula is affecting the inner ear. This can result in a decreased ability to move the face on the affected side, including the eye, mouth, and cheek.
13. Ataxia: Ataxia is a disorder of movement coordination that can occur in individuals with CAF, particularly if the fistula is affecting the inner ear. This can result in a decreased ability to control movement and coordination, leading to unsteadiness or clumsiness.
14. Numbness or tingling in the face: Numbness or tingling in the face can occur in individuals with CAF, particularly if the fistula is affecting the inner ear

Diagnosis

To diagnose this condition and determine the best course of treatment, a number of tests and diagnostic procedures may be performed.

Here is a list of common tests and diagnoses for congenital auricular fistula:

1. Physical examination: A physical examination of the ear is usually the first step in diagnosing a congenital auricular fistula. The doctor will look for any signs of an abnormal connection between the middle ear and the skin of the external ear, such as a visible fistula or a small opening in the ear.
2. Otoscopy: Otoscopy is a procedure in which a doctor uses a special tool, called an otoscope, to examine the ear. This tool allows the doctor to see inside the ear canal and assess the health of the ear drum and middle ear.
3. Tympanometry: Tympanometry is a test that measures the movement of the ear drum in response to changes in air pressure. This test can help determine if there is a problem with the middle ear, such as fluid buildup or a perforated ear drum.
4. Audiology testing: Audiology testing is a series of tests that measure a person’s hearing ability. This can include pure-tone audiometry, speech audiometry, and impedance audiometry.
5. CT scan: A CT (computed tomography) scan is a type of X-ray that creates detailed images of the head and neck, including the ear. A CT scan can help identify any structural abnormalities in the ear, such as a congenital auricular fistula.
6. MRI: An MRI (magnetic resonance imaging) is a type of imaging test that uses strong magnetic fields and radio waves to create detailed images of the body. An MRI can provide more detailed images of the ear and surrounding tissues than a CT scan.
7. Radiography: Radiography is a type of X-ray that creates images of the bones and tissues in the body. A radiograph of the head and neck can help identify any abnormalities in the ear, such as a congenital auricular fistula.
8. Hearing tests: Hearing tests are a series of tests that assess a person’s ability to hear sounds at different frequencies and volumes. This can include pure-tone audiometry, speech audiometry, and impedance audiometry.
9. Auditory brainstem response (ABR) test: The ABR test is a test that measures the electrical activity of the auditory nerve and brainstem in response to sound. This test can help determine if there is a problem with the hearing nerve or the brainstem.
10. Electrocochleography (ECOG): Electrocochleography is a test that measures the electrical activity of the inner ear in response to sound. This test can help determine if there is a problem with the inner ear, such as Meniere’s disease.
11. Stapedial reflex test: The stapedial reflex test is a test that measures the movement of the stapedius muscle in response to sound. This test can help determine if there is a problem with the middle ear.
12. Vestibular-evoked myogenic potential (VEMP) test: The VEMP test is a test that measures the muscle responses in the neck in response to sound. This test can help determine if there is a problem with the vestibular system, which is responsible for balance and spatial orientation.

Treatment

Treatments for congenital auricular fistula:

1. Observation: In some cases, the fistula may close spontaneously, and observation may be the only treatment required.
2. Antibiotics: In the case of infections, antibiotics may be prescribed to clear the infection.
3. Tympanostomy tubes: Tympanostomy tubes may be inserted into the eardrum to allow ventilation and drainage of fluid, reducing the risk of infection.
4. Myringotomy: A myringotomy is a surgical procedure where a small incision is made in the eardrum to allow fluid to drain.
5. Mastoidectomy: In some cases, a mastoidectomy may be necessary to remove infected mastoid bone.
6. Middle ear exploration: A middle ear exploration may be necessary to determine the extent of the fistula and to determine the best course of treatment.
7. Tympanic membrane closure: The tympanic membrane can be closed surgically, either by suturing or with the use of a patch.
8. Columellar reconstruction: In some cases, the external ear canal may need to be reconstructed to improve hearing.
9. Osteoplasty: Osteoplasty is a surgical procedure that involves reshaping the bones of the middle ear to improve hearing.
10. Stapedectomy: A stapedectomy is a surgical procedure that involves removing the stapes bone and replacing it with a prosthesis to improve hearing.
11. Ossiculoplasty: An ossiculoplasty is a surgical procedure that involves reconstructing the bones of the middle ear to improve hearing.
12. Tympanoplasty: Tympanoplasty is a surgical procedure that involves repairing the tympanic membrane and the bones of the middle ear.
13. Osteotomy: An osteotomy is a surgical procedure that involves cutting and reshaping bones to improve hearing.
14. Stapedotomy: A stapedotomy is a surgical procedure that involves making a small incision in the stapes bone to improve hearing.
15. Cochlear implant: A cochlear implant is an electronic device that can be implanted into the inner ear to provide hearing.
16. Auditory brainstem implant: An auditory brainstem implant is an electronic device that can be implanted into the brainstem to provide hearing.
17. Bone-anchored hearing aid: A bone-anchored hearing aid is a device that uses bone conduction to provide hearing.
18. Middle ear implant: A middle ear implant is a device that can be implanted into the middle ear to provide hearing.
19. Hearing aids: Hearing aids can be used to amplify sound and improve hearing.
20. Speech therapy: Speech therapy can be used to help individuals with hearing loss to improve their communication skills.

Medications

Drugs treatments for congenital auricular fistula:

1. Antibiotics: Antibiotics are the first line of treatment for infections of the preauricular sinus. The choice of antibiotics depends on the type of bacteria causing the infection. Commonly used antibiotics include amoxicillin, cephalosporins, and penicillins.
2. Pain relievers: Pain relievers such as acetaminophen or ibuprofen can help relieve pain and reduce inflammation associated with the infection.
3. Corticosteroids: Corticosteroids, such as prednisone, can help reduce inflammation and prevent scarring. They are often used in conjunction with antibiotics.
4. Antiseptics: Antiseptics, such as povidone-iodine or hydrogen peroxide, can be used to clean the fistula and reduce the risk of infection.
5. Stenting: Stenting can be used to keep the fistula open and prevent closure during the healing process.
6. Drainage: Drainage can be used to remove fluid or pus from the fistula.
7. Antifungal agents: Antifungal agents, such as itraconazole or fluconazole, can be used to treat fungal infections of the preauricular sinus.
8. Antiviral agents: Antiviral agents, such as acyclovir or valacyclovir, can be used to treat viral infections of the preauricular sinus.
9. Immune modulators: Immune modulators, such as interferon, can be used to enhance the body’s immune response to infections and promote healing.

It is important to note that the choice of treatment will depend on the individual case and the extent of the fistula. In some cases, multiple treatments may be necessary to achieve the best outcome.

References