What is the pathophysiology of otitis externa?
Otitis externa is associated with infectious, inflammatory ear and head conditions. Gross pathology for otitis externa will include erythema of the ear canal, along with eczema-like scaly, shedding of the skin. It also includes visible ear canal swelling, as well as potentially cellulitis of the pinna and otorrhea.
How does otitis externa affect hearing?
Narrowing of the ear canal If you have long-term (chronic) otitis externa, thick and dry skin can build up inside your ear canal. This causes the ear canal to narrow (stenosis), which may affect your hearing and, in rare cases, can even cause deafness.
What is the most common cause of otitis externa?
The most common cause of otitis externa is a bacterial infection, although fungal overgrowth is a principal cause in 10 percent of cases. 4 Otitis externa can also result from any of a broad range of noninfectious dermatologic processes.
What is the most common cause of obstruction of the external ear canal?
The common causes of external ear canal obstruction are cerumen, foreign bodies, the use of earplugs, the use of tight-fitting diving hoods, and swelling and congestion of canal skin. The treatment of external ear canal barotrauma is similar to that for middle ear barotrauma.
Which are risk factors for developing otitis externa?
Risk factors
- Swimming. People who swim regularly stand a higher chance of developing otitis externa, particularly those who swim in unsanitary water.
- Warm weather.
- Ear damage.
- Skin conditions.
- Excessive earwax.
- Otitis media (middle ear infection).
- Weakened immune system.
How do you describe otitis externa?
Otitis externa, also called swimmer’s ear, is an inflammation, irritation, or infection of the external ear canal. Swimmer’s ear is caused by fungi or bacteria. Water that remains trapped in the ear canal (when swimming, for example) may provide a source for the growth of bacteria and fungi.
Which of the following describes external otitis?
External otitis is an acute infection of the ear canal skin typically caused by bacteria (Pseudomonas is most common). Symptoms include pain, discharge, and hearing loss if the ear canal has swollen shut; manipulation of the auricle causes pain. Diagnosis is based on inspection.
What is the complication of otitis externa?
Potential complications of otitis externa include malignant otitis externa, mastoiditis, osteomyelitis, and intracranial spread. Malignant otitis externa is an extension of OE into the mastoid and temporal bones.
What is the difference between otitis media and otitis externa?
Otitis means inflammation of the ear. The inflammation is usually due to an infection. Otitis externa means that the inflammation is confined to the external part of the ear canal and does not go further than the eardrum. See separate leaflet called Ear Infection (Otitis Media), for an infection of the middle ear.
How is otitis externa diagnosed?
Diagnosis. Acute otitis externa is diagnosed clinically based on signs and symptoms of canal inflammation (Table 24; Figures 1 and 2). Presentation can range from mild discomfort, itching, and minimal edema to severe pain, complete canal obstruction, and involvement of the pinna and surrounding skin.
What is the function of the external auditory canal?
The external auditory canal (EAC) is a bony and cartilaginous tube lined by a thin layer of stratified squamous epithelium. The main function of the EAC is to transmit sound from the pinna to the middle ear. The EAC also has a self-cleaning mechanism.
Otitis externa is most commonly caused by infection (usually bacterial, although occasionally fungal), but it may also be associated with a variety of noninfectious systemic or local dermatologic processes.
What is the effect of the external ear on bone conduction?
Effect of the external ear on Bone conduction thresholds Tondorf (1968) provided the explanation for the external canal component of bone conduction in order to account for the occlusion effect, in which low frequency bone-conducted signals are perceived as louder when the ear canal is occluded than when it is unoccluded.
What is the external ear composed of?
The external ear is composed of the pinna and the ear canal, ending at the tympanic membrane. PINNA Pinna is a latin term for wing or projecting part of ear lying outside head.