INFECTION OF THE EXTERNAL EAR.ppt

1、INFECTION OF THE EXTERNAL EAR,Anatomy and physiology,The outer 40%: Cartilaginous Thin layer of subcutaneous tissue. The inner 60%: Osseous. Tympanic ring Very scant soft tissue between the skin, periosteum, and bone. Isthmus,Anatomy and physiology,2.5 cm. Posterosuperior part is about 6 mm shorter

2、than anteroinferior portion. Canal curves slightly superiorly and posteriorly in a gentle S shape. Upward, outward, and backward.,Anatomy and physiology,Self-protecting and self-cleansing. Cerumen sloughs externally. Instrumentation and excessive cleansing disturb primary protective barrier infectio

3、n. Wax accumulation.,Anatomy and physiology,Posterior bony canal: anterior boundary of the mastoid cavity. several vessels penetrate the canal (tympanomastoid suture). Superior: infratemporal fossa and base of the skull. Anterior: parotid gland and temporomandibular joint.,Anatomy and physiology,Lym

4、phatic drainage: Anteriorly and superiorly: preauricular lymphatics in parotid gland and superior deep cervical nodes. Inferior: infra-auricular nodes near the angle of the mandible. Posterior: postauricular nodes, the superior deep cervical nodes.,Anatomy and physiology,ECA superficial temporal and

5、 posterior auricular artery. Superficial temporal and posterior auricular veins retromandibular vein, external jugular vein, sigmoid sinus.,Anatomy and physiology,Sensation: trigeminal (V) facial (VII) auriculotemporal br. glossopharyngeal (IX) vagus (X) nerves cervical plexus (C2-3) greater auricul

6、ar nerve. Muscles of the ear, anterior, superior, and posterior auricular facial nerve (VII).,Otitis externa,Acute, subacute, or chronic. Acute otitis externa: bacterial infection. break in the normal skin/cerumen protective barrier. elevated humidity and temperature. swimmers ear.,Acute otitis exte

7、rna,Removal of the protective lipid film from the canal bacteria enter the apopilosebaceous unit. Itching. Instrumenting the canal with a cotton swab or fingernail. Proliferation of bacteria in locally macerated skin. Itch-scratch cycle.,Acute otitis externa,Swollen soft tissues distract the periost

8、eal lining of the bony canal pain. Purulent discharge. Auricle and periauricular soft tissues may become involved.,History,When the ear was last perfectly well. Length of time. The number of occurrences. The nature and severity of pain. Antecedent otologic disease. Previous auricular instrumentation

9、 or trauma. Predisposing factors: diabetes, radiotherapy, immunosuppression. Pain, fullness, itching, hearing loss.,Physical Examination,Red, swollen, protruding? Obvious discharge? Auricle and periauricular tissues. Normal epidermal architecture? Erythema or cellulitis spreading to the periauricula

10、r tissues, face, and neck? Tug upward and backward pain.,Physical Examination,Clean the canal thoroughly. Examine it under good illumination. Instrumentation: Microscope. Lying supine in the chair. Avoid possible vasovagal response (Arnolds nerve, a branch of cranial nerve X). Gentleness and thoroug

11、hness.,Bacteriology,Pseudomonas aeruginosa. Proteus mirabilis. Staphylococci. Streptococci. Gram-negative bacilli.,Bacteriology,Mild or uncomplicated infection: culture is ordinarily not taken. mixed growth of organisms. Recalcitrant infections: culture may assist in the choice of antibiotic therapy

12、.,Staging,Senturia et al.: Preinflammatory. Acute inflammatory: mild, moderate, severe. Chronic inflammatory.,Preinflammatory stage,Removal of the protective lipid layer and acid mantle. Plugging of the apopilosebaceous unit. Stratum corneum becomes edematous. Obstruction continues, a sense of fulln

13、ess and itching begins.,Acute inflammatory stage,Pain and tenderness of the auricle. Earliest stage: mild erythema and minimal edema. small amount of clear or slightly cloudy secretion. Moderate stage pain and itching increase, more edema and a thicker, more profuse exudate.,Acute inflammatory stage

14、,Severe inflammatory stage: increased pain and obliteration of the lumen of the canal. profuse greenish-gray, purulent exudate. edema of the canal skin may obscure the tympanic membrane. small white papules. P. aeruginosa or another gram-negative bacillus. adjacent soft tissues and cervical lymph no

15、des.,Chronic inflammatory stage,Less pain but more profound itching. Skin is thickened, and superficial flaking may be seen. Tympanic membrane may have a dull appearance. Mild edema extend to the skin of the concha. Auricle & concha: eczematization, lichenification, superficial ulceration.,Different

16、ial Diagnosis,Necrotizing external otitis. Bullous external otitis. Granular external otitis. Perichondritis. Chondritis. Relapsing polychondritis. Furunculosis, and carbunculosis. Dermatoses (psoriasis, seborrheic dermatitis). Carcinoma (earliest stages),Medical Treatment,Frequent and thorough clea

17、ning. Judicious use of appropriate antibiotics. Treatment of associated inflammation and pain. Recommendations regarding the prevention of future infections.,Medical Treatment,Mildest form: Cleaning. Antibiotic otic drop: neomycin-hydrocortisone (Cortisporin or Coly-Mycin S Otic). Ciprofloxacin opht

18、halmic solution (Ciloxan). Pseudomonas.,Medical Treatment,Moderate Stage: antibiotic drops at least 2 to 3 days after the cessation of pain, itching, and drainage. insert a gauze strip or wick. oral analgesic. acidifying drop. oral antibiotics in both the mild and moderate stages is of no proven val

19、ue.,Medical Treatment,Severe Stage : Cleaning Packing Antibiotic drops (anti-Pseudomonas) Oral antibiotic with broad-spectrum coverage: antistaphylococcal penicillins. first-generation cephalosporins. antipseudomonal fluoroquinolones ( 18 y/o).,Medical Treatment,Severe Stage : Warm soaks (normal sal

20、ine or a mild aluminum sulfatecalcium acetate solution). Culture. 10 to 14 days. Hospitalization, vigorous daily local care, repeat culturing, and intravenous antibiotics.,Medical Treatment,Chronic Stage: Triamcinolone acetonide 0.25% cream or ointment (Kenalog). Dexamethasone sodium phosphate 0.1% (Decadron) ophthalmic drops.,Recalcitrant Otitis Externa,Noncompliance or chronic instrumentation of the canal skin. If no progress is made in the office, admit the patient. Chronic midd