Otoscopía, ¿qué veo? - Docencia de Pregrado - Otorrinolaringología, Universidad de Chile

Introduction to Otoscopy

In this section, Dr. Cecilia Maquiavelo introduces the topic of otoscopy, focusing on the anatomy of the ear, particularly the external and middle ear, common pathologies, and their implications.

Anatomy of the Ear

• The ear is divided into three parts:

• External ear: from the auricle to the tympanic membrane.

• Middle ear: includes the tympanic membrane, ossicular chain, eustachian tube.

• Internal ear: from oval window to cochlea and vestibular labyrinth.

• Structures in the auricle include:

• Helix, antihelix with crura, triangular fossa, concha.

• Earlobe containing subcutaneous fat cells.

Clinical Significance

• When examining a patient with otalgia (ear pain), gently mobilizing the tragus can indicate external ear pathology (Tragus sign).

• Normal variations like Darwin's tubercle are common and considered vestigial structures shared with primates.

Common Pathologies

• Preauricular fistula and minor malformations like protruding ears or cryptotia can be observed.

• Other conditions include preauricular papillomas and microtia (underdevelopment of the ear).

Ear Infections and Trauma

This section covers infections caused by bacteria or viruses in the outer ear. It also discusses traumatic injuries that can occur in the auricle.

Infections

• Bacterial infections like perichondritis require systemic antibiotics for treatment.

• Viral infections such as herpes zoster can lead to vesicles around the meatus with associated symptoms like facial paralysis.

Traumatic Injuries

• Trauma ranges from minor lacerations to avulsions; high-energy trauma may cause otohematoma leading to cartilage necrosis if untreated.

• Severe cases result in cauliflower deformity due to hematoma organization and fibrosis causing cartilage necrosis.

Benign Tumors in Auricle

This part discusses benign tumors that may appear on the auricle including hemangiomas, fibromas, lipomas, and chondromas.

Benign Tumors

Cancer Types and Skin Lesions

In this section, the speaker discusses different types of cancer such as squamous cell carcinoma and melanoma, along with skin lesions like keloid scars and earwax plugs.

Carcinomas and Melanomas

• Squamous cell carcinoma has a 15% metastasis rate when it affects cartilage.

• Melanoma, although less common, is highly aggressive with a high metastatic potential.

• Melanomas in the ear account for only 1% of all melanomas.

Skin Lesions and Piercings

• Keloid scars are thickened, dysfunctional scars that can occur after piercing or any skin injury.

• Earwax plug accumulation is a common reason for consultation and can be iatrogenic due to improper cleaning methods.

Ear Canal Conditions

This part covers conditions like keratosis obturans, foreign bodies in the ear canal, and the importance of safe removal procedures.

Ear Canal Conditions

• Keratosis obturans involves an accumulation of keratinized epithelial scales but does not invade bone.

• Foreign bodies in the ear canal vary from organic (insects) to inorganic (beads), often seen in children or adults with neurological issues.

Foreign Body Removal

• Extraction of foreign bodies should be minimally traumatic; removal methods depend on the nature of the object.

• Extraction should never be attempted forcefully; cooperation from the patient or anesthesia may be necessary.

Infections and Trauma

This section delves into infections like otitis externa, trauma-related injuries from scratching or improper cleaning, and structural abnormalities in the ear canal.

Infections and Trauma

• Eczema can predispose individuals to outer ear infections like otitis externa.

• Traumatic injuries from scratching can lead to hematomas within the ear canal walls.

Structural Abnormalities

• Acute traumatic ruptures of the eardrum can result from forceful movements during cleaning or scratching activities.

Movilización del Trago y Otalgia

This section discusses otalgia and localized ear infections, focusing on folliculitis caused by bacteria like Staphylococcus aureus. It also covers diffuse external otitis, its symptoms, causes, and treatments.

Movilización del Trago y Otalgia

• Folliculitis in the ear canal is often caused by Staphylococcus aureus due to microtraumas like scratching or using cotton swabs.

• Diffuse external otitis involves more extensive inflammation of the external auditory canal, leading to severe pain, positive tragus sign, and potential otorrhea.

• Treatment for diffuse external otitis includes cleansing and topical medication targeting Pseudomonas aeruginosa with ciprofloxacin drops.

• Otomycosis, a fungal infection in the ear, can occur independently or alongside bacterial infections, characterized by itching rather than pain.

• Common fungi causing otomycosis include Aspergillus species with intense itching as a cardinal symptom.

Otitis Externa and Miringitis Aguda

This part explores acute miringitis without middle ear effusion and differentiates it from fungal infections. It also touches upon necrotizing external otitis.

Otitis Externa and Miringitis Aguda

• Miringitis aguda presents as redness and inflammation of the tympanic membrane without middle ear effusion.

• Acute miringitis resolves spontaneously within 48 to 72 hours without significant blood content in the ear discharge.

• Necrotizing external otitis involves rare pathological processes invading squamous tissue in the auditory canal progressing to bone destruction.

Otitis Externa Necrotizante y Colesteatoma

This segment delves into necrotizing malignant otitis externa affecting the temporal bone and cholesteatoma characterized by squamous tissue invasion leading to bone destruction.

Otitis Externa Necrotizante y Colesteatoma

• Necrotizing malignant otitis externa primarily caused by Pseudomonas aeruginosa affects soft tissues like cartilage and bone leading to cranial neuropathies.

• Cholesteatoma is an uncommon condition involving squamous tissue invasion progressing towards bone destruction within the auditory canal.

Procesos Neoplásicos en el Conducto Auditivo Externo

This part addresses neoplastic processes like squamous cell carcinoma in the external auditory canal requiring imaging studies for diagnosis before initiating oncological treatment due to their poor prognosis.

Procesos Neoplásicos en el Conducto Auditivo Externo

Anatomy of the Middle Ear Structures

In this section, the speaker delves into the anatomy of the middle ear structures, highlighting key ligaments and areas that provide support within the ear.

Ligaments and Support Areas

• Ligaments supporting the hammer in position are visible occasionally.

• The area below these ligaments, known as "pars tensa," offers significant support.

• Above these ligaments lies an area lacking fibrous tissue called "pars."

Structure of the Fibrous Ring and Middle Ear Levels

This part focuses on the fibrous ring structure and delineates three levels within the middle ear.

Fibrous Ring Structure

• The fibrous ring, also known as anulus or Gerl's ring, covers almost the entire circumference except for a portion of pars flaccida.

• During otoscopy, visibility is limited to what can be seen through the tympanic membrane.

Middle Ear Levels

• Three levels in the middle ear: epitympanum housing upper chain portions, mesotympanum at tympanic boundaries, and hypotympanum as the lowest part inaccessible via otoscopy.

Imagining Hidden Middle Ear Structures

This segment encourages imaginative visualization of hidden middle ear structures not typically visible during otoscopy.

Visualizing Hidden Structures

• The handle of the hammer is observable during otoscopy while its head is located in the attic out of sight.

• Short process of incus extends posteriorly into attic; not visible in a healthy ear but articulates with long process connecting to stapes.

Understanding Spatial Orientation in Otoscopy

Exploring spatial orientation cues for understanding tympanic membrane positioning during otoscopy.

Spatial Orientation Cues

• Spatial orientation determined by tracing a line along hammer handle intersecting perpendicularly at umbo level to establish four quadrants during otoscopy.

Vascularization and Coloration Patterns in Otoscopy

Discussing vascularization patterns and coloration nuances observed during otoscopic examinations.

Vascularization Patterns

• General vascular reinforcement around perimalleolar region noted on tympanic membrane.

Coloration Insights

Otitis Media and Ear Pathologies

In this section, the speaker discusses various aspects of otitis media and ear pathologies, including symptoms, signs, and potential complications.

Color of Otorrhea

• The color of otorrhea can provide insights into the type of content present in the ear discharge.

• Different colors such as serous, cerumenous, or greenish (indicative of Pseudomonas aeruginosa containing pyocyanin) can help in diagnosing specific pathologies.

• For instance, greenish discharge may suggest Pseudomonas infection associated with external otitis.

Significance of Tragus Sensitivity

• Tragus sensitivity refers to pain or tenderness upon pressure on the tragus.

• This sign is primarily linked to external ear pathology rather than middle ear conditions like acute otitis media.

• Acute otitis media commonly occurs due to bacterial inflammation following upper respiratory tract infections.

Progression of Acute Otitis Media

• Acute otitis media involves bacterial inflammation that ascends from the upper respiratory tract through the Eustachian tube to affect the middle ear mucosa.

• Initial stages manifest as hyperemia and pain, progressing to vascular engorgement with visible erythema.

• The presence of fluid in the middle ear leads to characteristic signs like bulging tympanic membrane due to increased pressure.

Complications and Management

This segment delves into complications arising from acute otitis media, perforations of the tympanic membrane, chronic otitis media scenarios, and their management strategies.

Tympanic Membrane Perforation

• Tympanic membrane perforation can occur during inflammatory processes within acute otitis media.

• A perforated membrane may result in otorrhea (ear discharge), potentially accompanied by blood due to rupture.

• While such perforations are usually transient and self-healing within 48–72 hours for small ones, severe infections can lead to lasting consequences.

Chronic Otitis Media Sequelae

• Persistent tympanic membrane perforations beyond three months indicate chronic otitis media development.

• These perforations contribute to conductive hearing loss termed hypacusia due to sound transmission impairment.

• Inflammatory changes in the tympanic membrane post-infection can lead to scar tissue formation known as myringosclerosis.

Prevention Strategies for Chronic Otitis Media

This part focuses on preventive measures for chronic otitis media aimed at reducing recurrent infections and complications.

Chronic Otitis Media Management

• Simple chronic otitis media involves varying degrees of tympanic membrane perforations that induce conductive hearing loss.

• Water entry poses a significant risk for superinfections in patients with chronic otitis media; hence avoiding water contact is crucial.

Preventive Measures

• Patients are advised against submerging their heads underwater or exposing ears directly to water sources.

Compuesta por un Epitelio Escamoso Queratinizado

The discussion focuses on the composition and characteristics of a specific type of epithelium found in the ear, highlighting its destructive nature and different types.

Epithelium Composition

• Describes the epithelium as squamous keratinized epithelium that abnormally accumulates in the ear.

• Histologically identified as a benign squamous cell cyst composed of two main components: matrix or content, and perimatrix or lamina propria.

Destructive Nature

• The matrix consists of squamous keratinized epithelium providing structural support, while the perimatrix is an inflammatory granulation tissue with proteolytic enzymes leading to bone destruction.

• Two forms of acquired cholesteatoma are discussed: primary (seen as retraction pockets weakening the tympanic membrane) and secondary (resulting from perforation due to chronic otitis media or otologic surgery).

Colesteatoma Adquirido y Congénito

Explores acquired and congenital cholesteatomas, detailing their pathogenesis, clinical presentation, and potential complications.

Acquired Cholesteatoma

• Acquired cholesteatoma enters the middle ear through the tympanic membrane, causing bone destruction and foul-smelling otorrhea.

• Complications may include severe otitis manifestations like meningitis, labyrinthitis, facial paralysis, intracranial abscesses, and potentially fatal conditions.

Congenital Cholesteatoma

• Congenital cholesteatoma originates from embryonic skin remnants within a healthy tympanic membrane presenting as a whitish mass.

• Rare extrapulmonary tuberculosis form can be mistaken for cholesteatoma; suspicion arises from painless long-lasting otorrhea in multiple tympanic perforations.

Granuloma de Colesterol y su Caracterización

Discusses cholesterol granulomas in detail including their formation process, appearance on examination, and implications for patient management.

Granuloma Formation

• Cholesterol granulomas are benign lesions with a unique bluish appearance on the tympanic membrane believed to originate from hemoglobin breakdown by macrophages.

• Macrophages react to erythrocyte cholesterol triggering inflammation leading to granuloma formation characterized by a thin connective tissue encapsulating cholesterol-laden macrophages.

Clinical Implications