Affections of External Ear PDF

Affections of external ear Dr. ABDALLAH B. Outline Anatomy of external ear. Congenital anomaly of external ear. Keloids. Perichondritis. Otitis Externa. Keratosis obturans. Tumors of EAC. Tympanic membrane perforation. Anatomy of External ear. The external ear...

Affections of external ear Dr. ABDALLAH B. Outline Anatomy of external ear. Congenital anomaly of external ear. Keloids. Perichondritis. Otitis Externa. Keratosis obturans. Tumors of EAC. Tympanic membrane perforation. Anatomy of External ear. The external ear consist of auricle and external auditory canal. The auricle/pinna consist mostly of fibroelastic cartilage except the lobule which contains fat. The EAC extends from the lateral part of the TM to the external auditory meatus. Its about 2.5cm in length. EAC has an outer cartilaginous part and inner bony part.  The cartilaginous part contains thick skin and has hair follicles, sebaceous and apocrine glands. The bony part contain thin skin and its devoid of hair follicles and glands.  The TM is pearly white in appearance. It has three layers: cuticular, fibrous and mucous. 1.Congenital anomaly of external ear 1.Microtia Congenital deformity in which the pinna is malformed and underdeveloped. Its always associated with anomalies of EA,middle and inner ear. Can be unilateral or bilateral. Hearing loss is frequent. 2.Macrotia Excessive large pinna. Most exaggerated part is the scaphoid fossa. 3. Preauricular sinus/pit. Blind ending narrow pit or tube. Due to failure of fusion of auricular hillocks. Three types according to the location of pits : pits located on the middle area on the crus (type 1) , pits located on the superior area of the crus (type 2), and pits located on the cymba concha (type 3) Most are harmless, occasionally they can get infected, form retention cysts and cause chronic discharge. 4.Congenital atresia of EAC It can occur alone or with microtia. When it occur alone it is due to failure of canalization of the ectoderm core that fill the dorsal part of first brachial cleft. When it occur with microtia it is associated with middle and inner ear abnormalities. The EAC is absent or appears as a blind pit.  Can be unilateral or bilateral. Hearing loss is common. Management of Congenital atresia of EAC Imagining: CT scan of temporal bone. Treatment: Hearing aid. Surgery. 2.Keloids/Hypertrophic scars. Keloid is a painless mass occurring after trauma or ear piercing. Common at the lobule and helix They are benign lesions. It occur in susceptible individuals, African descendants. Its firm and round. Cosmetic is the main issue. Treatment Small: intra-lesion. triamcinolone Large: Surgical excision with primary closure. Massage and intra-lesion steroid should be used after healing to prevent recurrence. 3.Perichondritis. Its an inflammation of perichondrium of auricle. It results from infection secondary to hematoma, laceration and surgical incision or from extension of infection from otitis externa. Etiological organism: Psuedomonas. Clinical presentation. Severe ear pain. Erythematous of pinna Induration of pinna. Tenderness of pinna. Fluctuation of pinna; indicates presence of an abscess and possible chondritis. Treatment. Early stages: systemic antibiotics ie ciprofloxacin. For abscess formation: drainage, resection of necrotic tissue and packing with antibiotic impregnated ribbon gauze. Complication : cauliflower ear. 4.Otitis externa Its an inflammation/infection of the external auditory canal. Its common in both gender. Peak age group is 21-30 due to increase outdoor activity. Common in tropical climates and summer due to increase humidity. Risk factors of otitis externa Environmental factors. Skin disease. High ambient temperature. Psoriasis. High humidity in ambient air. Eczema. Anatomical abnormalities of EAC. Trauma. Exostoses Foreign body. Hairy EAC. Cerumen/foreign body removal. Stenosis of the EAC. Hearing aids. Endogenous factors Others Lack or overproduction of Irritants( soaps and shampoo). cerumen Swimming. Systemic diseases. Purulent otitis media. Diabetes mellitus. Immunosuppression Clinical classification of otitis externa. Based on area involved. Based on the etiology Localized(Furunculosis) Infective: Diffuse. Bacteria: P.aurigunosa,S. aureus. Malignant. Fungus: Candida, Aspergillus Based on disease onset Virus: Varicella zoster. Acute: 6 weeks Contact dermatitis Classification on involved area Furunculosis. Its also called localized otitis externa. Its an infection of hair follicle. Causative agent: staphylococcus aureus. Its only seen in cartilaginous part of EAC Pathogenesis: Local mechanical trauma of EAC. Clinical presentation: Ear pain: severe and disproportion to the lesion. Reduced hearing. Tragal tenderness. Localized swelling of EAC. Purulent discharge if swelling rupture. Preauricular lymphadenopathy Treatment Aural toilet: if there is otorrhea; using 3% hydrogen peroxide. Antibiotics: ampiclox or amoxiclav. Anti-pain: Paracetamol or ibuprofen. Incision and drainage. Diffuse otitis externa. Diffuse Inflammation of meatal skin that may spread to involve the pinna and the cuticular layer of tympanic membrane. Commonly seen in hot and humid environment typically in swimmers Predisposing factors: Trauma to meatal skin. Skin maceration: due to hot atmosphere with excessive sweating and frequent bathing/swimming or discharge of CSOM Causative agent: P.aurigunosa, S.aureus and proteus mirabilis Symptoms : Itching Discharge(scanty) Ear pain Hearing loss. Signs : Meatal tenderness especially on movement of pinna or tragus compression. Purulent or watery discharge. Narrowing and edema of EAC Treatment Non-pharmacological: aural toilet. Keep the ear dry. Pharmacological: ciprofloxacin ear drops Paracetamol or ibuprofen. Prevention: wearing ear plugs during swimming/bathing. Prophylaxis acidification after swimming. Reduce frequency of washing the ear with soap. Malignant otitis externa. Its also known as necrotizing otitis externa. Its an aggressive disease of the EAC that begins in soft tissues of EAC and spread to the skull base via fissure of Santorin and to stylomastoid foramen and the jugular foramen via tympanomastoid suture. It doesn’t spread through pneumatized tracts hence middle ear is rarely involved. Predisposing Factors: Elderly and with diabetes mellitus is most commonly affected. This is due to microangiopathy of ear canal and increased pH of cerumen in diabetes. Immuno-compromised states i.e HIV/AIDS, myeloid malignancies and pharmacological immunosuppression. Causative agents: P.aeruginosa(90%), S.aureus, S.epidermidis, P. mirabilis, Klebsiela oxytoca, Fungus(A.Fumigatus, flavus and niger) Signs and symptoms Severe otalgia Facial nerve palsy: involvement of stylomastoid foramen Jugular foramen syndrome: involvement of Jugular foramen. Granulation tissues at bony cartilaginous junction(pathognomonic feature). Headache, fever, neck stiffness and altered level of conscious-indicate intracranial infection. Treatment Control of diabetes mellitus. Aural toilet Antibiotic ear drops and systemic ear drops Surgery : debridement of devitalized tissues/bone. Fungal otitis externa (Otomycosis) It’s a fungal infection of EAC. Causative organisms: Aspergillus nigra: black headed filamentous growth. Aspergillus fumigatus: brown. candida albicans: white/creamy deposits. Its seen in hot and humid environment. Secondary infection is seen in longstanding use of antibiotics for otitis externa/CSOM. Symptoms: Intense itching/pain/discomfort in the ear Watery ear discharge with musty odor. Signs: Erythematous canal with black/grey/white fungal mass. Candida species: cheesy white debris in ear canal Aspergillus niger: moist white plug dotted with black debris( wet newspaper) Aspergillus fumigatus :pale blue or green Treatment Aural toilet. Topical antifungal agents: Clotrimazole 1%/ketoconazole cream/drops. Analgesics. Keep the ear dry. Herpes zoster oticus It is a viral infection of the EAC, middle ear and inner ear due to reactivation of varicella zoster virus. Predisposing factor: reduced cell mediated immunity. o Immuno-compromised patients. o Physical or psychological stress; reactivates the virus Pathogenesis: Reactivation of varicella zoster(chickenpox) that’s in latent phase in geniculate ganglion leading to spread of virus along the sensory fibers of facial nerves(along the dermatomes) followed by vesicular eruption. Clinical presentation: Vesicles on TM,meatal skin and concha and postauricular groove. Severe ear pain.  Ear discharge Involvement of CN 7 and 8. Facial nerve palsy(Rumsey Hunt syndrome): Unilateral lower motor neurone palsy) Treatment Keep the ear dry and avoid scratching. Acyclovir 800mg TID/QID for 7-14 days Prednisolone 1mg/kg/day in case of facial nerve paralysis. Analgesia: Paracetamol/Ibuprofen. Complication: Post-Herpatic neuralgia Hearing loss 5.Keratosis obturans It is an abnormal accumulation of keratin in the medial portion of the EAC. It common affects adults between 30-60 years of age. Pathophysiology: o Faulty pattern of epithelial migration of epithelial layer of tympanic membrane and adjacent canal. o Excessive production of epithelia layer.  Clinical presentation o Severe ear pain-osseous part. o Hearing loss-conductive hearing loss. o Tinnitus. o Pearly white mass of keratin material and granulation o ulceration and widening of EAC.  Temporal bone CT scan: widening of the EAC with bone erosion. Treatment: o Keratolytic agent i.e salicyclic acid. o Surgical removal under general anaesthesia. o Canalplasty: for recurrent cases. The specimen removed should be sent to histopathology to rule out malignancy.  6 Tympanic membrane trauma Tympanic membrane trauma can be due to: Direct force due to a hair pin, matchstick or unskilled attempts to remove a foreign body. Sudden change in air pressure, e.g. a slap or a kiss on the ear or a sudden blast. Forceful Valsalva may rupture a thin atrophic membrane. Pressure by a fluid column, e.g. diving, water sports or forceful syringing. Fracture of temporal bone. Tympanic membrane trauma is associated with perforation. Classification Tympanic perforation According to duration Acute (< 3 months). Chronic (greater or equal to 3 months). According to presence of ear discharge. Dry perforation Wet perforation According to size of perforation Small (less or equal to 25% or one quadrant). Medium (25-50% or two quadrants). Large (50-75% or more than two quadrants). According to location Central perforation. Marginal perforation. Clinical manifestations: Symptoms Bleeding Otalgia Ear Fullness Hearing loss: conductive HL or mixed HL Tinnitus Physical examination Tympanic perforation assessment Location Size Fresh blood or clot If skull base fracture is occurred with CSF leakage, clear fluid is observed Associated complications Ossicular discontinuity. Facial Nerve Injury. Chorda tympani Nerve Injury. Management Keep ear clean and dry -Plug the ear with cotton while showering. -Avoiding inserting ear drops Analgesic-pain relief Antibiotics if infected If 3 months later, perforation still exists, tympanoplasty is indicated. Treat the complications accordingly Reference Cumming’s textbook of otorhinolaryngology. Ballenger’s Otorhinolaryngology Head and Neck Surgery, Sixteenth Edition Scott-Brown’s Otorhinolaryngology and Head and Neck Surgery Volume 1 Basic Sciences, Endocrine Surgery, Rhinology by John C Watkinson, Ray W Clarke (z-lib.org)