Audiology Lesson 4 - External Ear Disorders Flashcards
Describe how an ear examination is performed
Ear examinations are performed by means of an otoscope (typical of pediatric colleagues), or by means of an endoscope, but the best choice is represented by the microscope
During the otomicroscopic evaluation of your patient you have both hands free to perform a diagnostic evaluation.
IMPORTANT
You need to bring the auricle posteriorly and upward in order to bring the cartilaginous portion of the external auditory canal in the same axis of the bony portion of the external auditory canal
• (different in the pediatric age, in which the auricle is not brought upward but downward)
It is possible to draw two imaginary perpendicular lines: one along the manubrium of the malleus and the second one perpendicular at the level of the umbo, dividing the tympanic cavity into 4 sections:
Postero-superior - contains:
- long process of the incus
- the chorda tympani
- the stapes and the facial nerve
Postero-inferior - contains:
1. round window
Antero-inferior - contains:
no structures - makes it the best site for excisions during operations
Antero-superior - contains:
- the Eustachian tube recess
- Carotid artery
List the main symptoms related to ear disorders
Ear pain (otalgia) Ear discharge (otorrhea) Hearing loss Fullness Tinnitus Vertigo
Discuss the 2 eitiologies of ear pain
Ear pain may be due to:
- disorder that involves the ear - primary ear pain
- disorder that does not involve the ear - secondary ear pain (e.g. cancer of the pharnyx, TMJ etc)
Fully detail the innervation of the external ear
The external ear innervation is quite complicated, five nerves are involved:
A branch of CN 10 (Arnold’s nerve)
• Innervates the posterior wall of the external auditory canal / external auditary meatus and the conca.
• May induce cough reflex
The auriculo-temporal nerve (a branch of CN 5)
• Provides the innervation of the anterior portion of the external auditory canal and of the anterior part of the auricle
The great and small auricular nerves (branches of the cervical plexus)
• Provide innervation to the posterior portion of the auricle
The Ramsay-Hunt’s fibers and posterior auricular nerve (branches of CN 7)
• Provide the innervation to the posterior portion of the auricle and to a portion of the concha (which is also innervated by Arnold’s nerve) and related to Ramsay-Hunt syndrome
Discuss how earwax (cerumen) and foreign bodies are managed
Cerumen is produced from cells in the lateral third of the cartilaginous portion of the external auditory canal.
Ear wax and foreign bodies are common problems in clinical practice. Water irrigation can sufficiently take care of the problem.
Precaution should be taken not to perforate the tympanic membrane during the procedure
Scoop it out
Fully describe Perichondritis and it’s clinical presentation
Perichondritis is an infection of the cartilage of the perichondrium and of the skin in the external ear.
The affected auricle is bigger than the healthy one.
It’s important to perform a proper diagnosis of perichondritis because, if it is not properly treated, canrtilage destruction can lead to anesthetic result
Usually, perichondritides are supported by bacterial infections (Staphylococcus, Pseudomonas)
The patient complains of severe pain, there is a regional lymph nodes enlargement at the level of the neck near to the auricle, and fever can sometimes be present.
Fully describe Auricular hematoma and what it usually results from
Auricular hematoma is a complication that results from direct trauma to the auricle. It is a collection of blood between the cartilage and the perichondrium.
The situation requires rapid drainage of the blood collection and compression and dressing to avoid new collections and possible infections - which would lead to periperichondritis
It results from shearing forces which can lead to a separation of the auricular perichondrium from the underlying tightly adherent cartilage.
Fully describe Ramsay-Hunt syndrome
Ramsay-Hunt Syndrome is caused by Herpes Zoster reactivation of the facial nerve
Clinical picture: ▪ Vesicular eruptions in the concha and in the external acoustic meatus. ▪ Peripheral Facial nerve palsy. ▪ Ear pain ▪ Sudden Sensorineural Hearing loss ▪ Acute Unilateral Vestibular loss.
Fully describe Acute Otitis Externa including etiology, symptoms and diagnosis
It is a really frequent infection during summer months (this is in contrast to otitis media which, is a typical infection of winter season).
- typical of habitual swimmers with a 5x greater risk
It is a diffuse infection of the skin lining the external ear; usually a bacterial eitiology such as Staphylococcus aureus and occasionally Pseudomonas aeruginosa.
Symptoms
▪ Severe ear pain (a frequent clinical finding is pain during palpation of the tragus),
▪ Purulent aural discharge
▪ Hearing loss & Fullness: this is Conductive Hearing Loss
Diagnosis
Performed by means of otomicroscopy or otoscopy.
Otoscopic investigation reveals a diffused swelling of the skin of the external ear, we can observe a purulent aural discharge, and usually the tympanic membrane is not visible due to the stenosis of the external auditory
canal;
however, if it’s possible to observe the tympanic membrane and you will see that it is completely normal.
REMEMBER acute otitis externa is a type of dermatitis, it is simply an infection of the skin.
Discuss Carcinoma of the external auditory canal and how its distinguished from Acute Otitis External
Carcinoma of the external auditory canal can be very similar to Acute otitis externa.
You should suspect it when there is a persistent external otitis characterized by pain and ear discharge which does not resolve after a proper treatment.
Usually, basal cell carcinoma, or squamous cell carcinoma.
Basal cell carcinomas - frequent in pts with long exposure to the sun
Squamous cell carcinomas (about ¾ of invasive tumours of the external auditory canal and the
middle ear. Must be caught quickly as they are very invasive
Fully describe Otomycosis
Mycotic infections, usually due to Aspergillus niger, or Candida albicans.
It is typical of summer months and warm climates (like acute otitis externa).
Prolonged and improper use of steroid ear drops can be related to otomycosis; this is because steroid ear drops change the Ph of the skin, which supports an otomycotic infection.
Symptoms:
- Mild pain
- Hearing loss (conductive)
- Aural discharge
- Ear itch
Suppuration can occur due to superimposed bacterial infection. Commonly due to pseudomonas species and proteus species.
Diagnosis:
Performed by means of otomicroscopic investigation - identified right away
Describe Hemorrhagic Otitis externa
Hemorrhagic Otitis externa usually has a viral etiology, from upper airway viruses such as infuenza.
Viruses can damage the
the epithelial layer of the tympanic membrane and of the skin of the
external auditory canal (meatal skin) - resulting in Toxic Capillary damage.
The result is the presence of a hemorrhage that we can be observed during
otomicroscopy, and therefore the diagnosis is very very easy.
The treatment is administration of steroids and antibiotics to avoid a bacterial superinfection.
Fully describe Malignant otitis externa, why its on the rise, pathophysiology and symptoms
Malignant otitis externa is a skull base osteomyelitis. it is characterized by a necrotizing process of the temporal bone due to:
▪ Bacterial infection (Pseudomonas Aeruginosa) or
▪ Mycotic infection (Aspergillus) of the external auditory canal and of the skull base
.
It usually begins as an external otitis but is then characterized by progressive involvement of the temporal bone with an involvement of the central nervous system
HIGH MORTALITY RATE
30-50%
Mainly caused by sepsis or meningitis. The people at most risk for malignant otitis externa are older patients with diabetes or immunocompromised patients. Therefore we should administer SYSTEMIC ANTIBIOTICS to these patients
The frequency of this condition has risen in the past decades due to rise of immunosuppresive treatments, radiation therapy, and AIDS
Important
Otomicroscopic findings in a patient with malignant otitis externa, they are not very different from the ones seen previously, and this is the reason why clinical findings are crucial to support this type of diagnosis.
PATHOPHYSIOLOGY
Begins as acute otisis externa - characterized by a progression and spread towards CNS, Cranial nerves, blood vessels which run through temporal bone, sigmoid sinuses (thrombophebitis can be observed)
SYMPTOMS
▪ Severe ear pain,
▪ Aural discharge,
▪ Hearing loss,
▪ Persistent granulation tissue and
▪ Swelling of the external auditory canal.
▪ Cranial neuropathies occur only in more advanced presentations of disease and the presence of a palsy of the cranial nerves is of pivotal importance to suspect a skull base osteomyelitis. The diagnosis is obviously performed by means of computerized tomography that reveals a destruction and an osteomyelitis.
Briefly discuss Auris Atresia
Auras atresia is a malformation of the external ear. A malformation of the external ear may be part of a syndromic situation and so, when you are dealing with a malformation of the external ear, you have to confirm or exclude a syndromic condition, and so we also need to evaluate other organs.
