Otitis Media - Definition and Pathophysiology

1. بنام خداوند جان وخرد Otitis Media

2. Otitis Media - Definition • Inflammation of the middle ear • May also involve inflammation of mastoid, petrous apex, and perilabyrinthine air cells

5. Eustachian Tube Lumen shaped like two cones with apex directed toward middle Mucosa has mucous producing cells and ciliated cells Connects middle ear and nasopharynx

6. Eustachian tube Adults ant 2/3- cartilaginous post 1/3- bony 45 degree angle isthmus 1-2 mm nasopharyngeal orifice 8-9 mm Children longer bony portion 10 degree angle isthmus larger nasopharyngeal orifice 4-5 mm in infants

7. Eustachian tube Usually closed Opens during swallowing, yawning, and sneezing Opening involves cartilaginous portion Tensor veli palatini responsible for active tubal opening No constrictor function

8. Eustachian tube Protection from nasopharyngeal sound and secretions clearance of middle ear secretions ventilation (pressure regulation) of middle ear

9. Pathology Edema, capillary engorgement, and PMN infiltration Epithelial ulceration and granulation tissue Fibrosis, influx of chronic inflammatory cells Increased columnar and goblet cells Osteitis Edema and polypoid changes

10. Pathology Eustachian tube abnormalities Impaired opening open in DS and American Indians shorter tube Impaired immunity children have poorer immune response less cytokines in nasopharynx in children with OM Inflammatory mediators Bacterial products induce inflam response with IL-1, IL-6, and TNF Allergy

11. Microbiology S. pneumoniae - 30-35% H. influenzae - 20-25% M. catarrhalis - 10-15% Group A strep - 2-4% Infants with higher incidence of gram negative bacilli

12. Bacteriology

13. Virology RSV - 74% of middle ear isolates Rhinovirus Parainfluenza virus Influenza virus

14. otitis media can be subclassified into Acute otitis media (AOM) otitis media with effusion (OME)

15. . AOM generally is characterized by rapid onset of signs and symptoms of inflammation in the middle ear accompanied by middle ear effusion (MEE).

16. Signs and Symptoms bulging or fullness of the tympanic membrane (TM) erythema of the TM and acute perforation of the TM with Otorrhea otalgia irritability fever

17. Physical Examination proper head and neck examination is invaluable Facial features( Down syndrome and Treacher Collins syndrome ) Examination of the oropharynx may show a bifid uvula or a cleft palate . . Hypernasality indicates velopharyngeal insufficiency , whereas hyponasality may be caused by obstructing adenoids or nasal obstruction due to nasal polyposis or deviated septum.

18. Pneumatic otoscopy Reduced or no mobility of the TM increased stiffness due to scarring or increased thickness of the TM . Total absence of mobility of the TM may also be due to an opening in the TM either as a perforation or a patent tympanostomy tube fluid levels or bubbles The position of the TM ranges from severely retracted to bulging. Mild to moderate retraction indicates negative pressure

19. Immittance Testing (Tympanometry) can be very useful in evaluating ear disease in children older than 6 months of age

20. Audiometry Behavioral audiometry requires cooperation of the child with the examination and the test is adapted to the age of the child Auditory brainstem audiometry (ABR) and transitory otoacoustic emissions (TOAE) are excellent methods for testing children who do not cooperate with behavioral hearing evaluation because of very young age or developmental delay Otoacoustic emissions (OAE) testing measures cochlear function (outer hair cells) and is a means of objective assessment of auditory function

21. Pathophysiology and Pathogenesis

22. The eustachian tube The eustachian tube in the infant is shorter, wider, and more horizontal than in the adult, which accounts for the high rate of otitis media in infants and children . By the age of 7 years, when the tube has a more adult configuration, the prevalence of otitis media is low The three physiologic functions of the eustachian tube are (1) pressure regulation (ventilation), (2) protection, and (3) clearance (drainage).

26. Allergy and Immunology , the causal mechanism is not understoodSeveral mechanisms by which allergy may cause otitis media : (1) the middle ear is a “shock organ” (target); (2) allergy may induce inflammatory swelling of the eustachian tube mucosa; (3) allergies produce inflammatory obstruction of the nose (4) bacteria-laden allergic nasopharyngeal secretions may be aspirated into the middle ear

27. Gastroesophageal Reflux reflux may be a causative factor in otitis media, with a potential role for antireflux therapy in the treatment of otitis media in some children, but adequate controlled trials have not been done with a potential role for antireflux therapy in the treatment of otitis media in some children, but adequate controlled trials have not been done.

28. Viruses Using PCR techniques, however, it has been possible to identify respiratory syncytial virus (RSV) , influenzavirus, adenovirus, parainfluenza virus, and rhinoviruses in MEE

29. Acute Otitis Media In a majority of these studies, the peak incidence of AOM was during the first 6 to 12 months of life The incidence decreases with age, and by the age of 7 years, few children Recurrent episodes of AOM are common in young childrenexperience episodes of AOM

30. Otitis Media with Effusion It may be difficult to determine the “true” incidence of OME because, by definitionOME is asymptomatic approximately 65% of OME episodes in children 2 to 7 years of age resolve within 1 month

31. Risk Factors (age, gender , race, prematurity, allergy , immunocompetence , cleft palate and craniofacial abnormalities , genetic predisposition) as well as environmental (upper respiratory infections , seasonality , day care , siblings , tobacco smoke exposure , breastfeeding , socioeconomic status , pacifier use, and obesity

32. Otitis media also is common in children with other craniofacial abnormalities or Down syndrome, also due to anatomic or functional eustachian tube abnormalities highest incidence of AOM is between 6 and 11 months of age,[39] and onset of the first episode of AOM before 6 months[39] or 12 months of age is a powerful predictor of recurrence. .[54] Some studies have found a significantly higher incidence of AOM in males as well as more recurrent episodes than in females, but others have not found this.[ studies have suggested a lower incidence of otitis media in African-American children than in white children46] Some studies have shown a possible association between low birth Otitis media is considered “universal” in infants younger than 2 years of age with unrepaired cleft palate.[65] After surgical repair of the palate, the occurrence of otitis media is reduced, probably because of improvement in eustachian tube function. weight and prematurity and otitis media, but others have not.

33. A study was conducted to assess the variation in environmental risk factors for otitis media across Western countries, including European countries, the United States, Canada, and Australia.[74] The main risk factors for otitis media were day care atendance, number of siblings, tobacco smoke exposure, breastfeeding, birth weight, socioeconomic status, and air pollution. However, the results indicated large variations in rates across the various countries: day care at ages 1 to 3 years: Sweden 75% versus Italy 6%; breastfed at 6 months: Norway 80% versus Poland 6%; and women smoking: Germany, France, and Norway 30% to 40% versus Portugal less than 10%.

34. Both epidemiologic evidence and clinical experience strongly suggest that otitis media frequently is a complication of an upper respiratory infection (URI). The incidence of AOM is highest during the fall and winter months and lowest during spring and summer months, which parallels the incidence of URI

35. Tobacco Smoke Exposure a metabolite of nicotine, in blood, urine, or saliva of the child and have been able to more accurately determine the association , between otitis media and smoke exposure tympanostomy , myringosclerosis

36. Bacterial Vaccines

37. Treatment Medical Surgical

38. Medical Treatment Amoxicillin is still the first-line antibiotic for non-severe episodes of AOM and, at 90 mg/kg per day in two divided doses For severe episodes of AOM, amoxicillin–clavulanic acid (amoxicillin 90 mg/kg per day and clavulanic acid 6.4 mg/kg per day in two divided doses) Cephalosporins should be considered as accepted first-line treatment only for patients with penicillin allergy Macrolides should be prescribed for patients with penicillin and cephalosporin allergies

39. Antibiotics • First line • Amoxil - 60-90 mg/kg divided tid • Ceftin - B lactam stable • Augmentin - B lactam stable • Bactrim, Pediazole • Second line • Augmentin • Ceftin • Rocephin • Macrolides - Zithromax, Biaxin

40. دو نکته مهم Treatment failure is defined as persistenceor recurrence of symptoms and signs 48 to 72 hours after institution of initial treatment. In such cases, the diagnosis should then be reassessed and antibiotics started if not given previously or changed to a broader-spectrum agent if antibiotics were previously prescribed (amoxicillin–clavulanic acid if amoxicillin failed to produce improvement and ceftriaxone for 3 days if amoxicillin–clavulanic acid was not effective) Tympanocentesis should always be considered if the child does not respond to the antibiotic treatment, in order to identify the bacteria in the MEE and to select an appropriate antibiotic.

41. Duration of Treatment Ten days of antibiotic treatment has been the standard Longer courses of antibiotics have also been proposed. In a randomized, double-blind trial of 10 days of amoxicillin versus 20 days of amoxicillin or 10 days of amoxicillin with an additional 10 days of amoxicillin-clavulanate, no advantage in treatment failure or duration of MEE was found with the longer courses.[123]

42. Decongestants/Antihistamines A meta-analysis of studies of decongestant-antihistamine preparations for AOM found no benefit of these agents for early cure, symptom resolution, or prevention of surgery or complications

43. Recurrent Acute Otitis Media . Many antibiotics have been studied, particularly amoxicillin and sulfisoxazole, used at one-half of their recommended daily dose and given once per day for months

44. Surgical Treatment myringotomy or tympanocentesis is helpful for relief of pain and allows samples to be obtained for culture to identify the pathogen and to guide in the selection of antibiotics, but provides no advantage in duration of effusion or recurrence of episodes of AOM

45. When preventive and medical treatments for recurrent AOM have failed, tympanostomy tube insertion is recommended. Adenoidectomy with and without Tonsillectomy

46. Tympanostomy tube insertion • Unresponsive OME >3 mos bil, or >6 mos uni, sooner if assoc hearing problems • Recurrent MEE with excessive cumulative duration • Recurrent AOM - >3/6 mos or >4/12 mos • Eustachian tube dysfunction • Suppurative complication

47. Intratemporal hearing loss TM perforation CSOM retraction pockets cholesteatoma mastoiditis petrositis labyrinthitis adhesive OM tympanosclerosis ossicular dyscontinuity and fixation facial paralysis cholesterol granuloma necrotizing OE Intracranial meningitis extradural abscess subdural empyema focal encephalitis brain abscess lateral sinus thrombosis otitic hydrocephalus Complications

48. Treatment - Recurrent AOM • Chemoprophylaxis • Sulfisoxazole, amoxicillin, ampicillin, pcn • less efficacy for intermittent propylaxis • Myringotomy and tube insertion • decreased # and severity of AOM • otorrhea and other complications • may require prophylaxis if severe • Adenoidectomy • 28% and 35% fewer episodes of AOM at first and second years

49. Otitis Media with Effusion Hearing testing should be done if MEE persists for 3 months or longer or at any time that language delay, learning difficulties or significant hearing loss is suspected. If the average hearing level is below 20 dB, watchful waiting is suggested, but if it is greater than 40 dB in the better ear, surgery is recommended.

50. Medical Treatment • Decongestant/Antihistamine • Antibiotics((1) amoxicillin (40 mg/kg/day) for 14 days plus a • decongestant/antihistamine combination for 28 days • Steroids