Otitis Media

J. MacCormick, MD, FRCSCAssociate Professor U of Ottawa

Division OtolaryngologyChildren’s Hospital Eastern Ontario

Images used in this lecture were obtained from the presenter’s collection, various textbooks and internet websites., particulaly Abraham Jacob MD, The Ohio State University. Their use is for educational purposes only.

Objectives

• Define the middle ear cavity• Compare and contrast acute otitis media and

serous otitis media with respect to natural history, etiology, prevalence, symptoms and signs

• List the complications of acute otitis media• Describe the contemporary management of

acute otitis media

The Eustachian Tube

The Eustachian Tube

• Connection between middle ear (ME) & nasopharynx (NP)

• Medial 2/3 fibro-cartilage; lateral 1/3 bony• Equalizes ME pressure with atmospheric pressure• Lined with respiratory epithelium

– Mucociliary clearance towards the NP – drains fluid from ME

• Usually closed to prevent reflux of NP contents into ME

• 13 mm @ birth; 36 mm in adulthood• More horizontal at birth; elongates and descends over

time

• ET and middle ear develop from the first pharyngeal pouch (endoderm)

• The external ear canal develops from the first branchial cleft (ectoderm)

• The ossicles develop from the 1st and 2nd branchial arches

• The interface between the first pharyngeal pouch and the first branchial cleft forms the tympanic membrane

Eustachian Tube Embryology

Eustachian Tube Dysfunction

• Abnormal cranial base anatomy– Bony anatomy– Abnormal musculature

• Tensor veli palatini and/or levator veli palatini, e.g. cleft palate

• Inflammation/edema• Physical obstruction (e.g. adenoids)• Usually “too closed” but can also be “too open”

(patulous Eustachian tube)

Eustachian Tube Musculature

EUSTACHIAN TUBE (ET) DYSFUNCTION

• Active Opening equalizes pressure in middle ear• If dysfunctional, air in middle ear space is gradually

absorbed– Negative middle-ear pressure– Retraction– With enough vacuum effect, fluid is sucked from the

surrounding tissue (effusion) • Increasing angulation of tube improves ET function

– 95% children normal ET function by age 7

ACUTE OTITIS MEDIA

• antecedent event (URI)• congestion mucosa Eustachian tube• negative middle ear pressure• aspiration of potential pathogens• accumulation of effusion• microbial pathogens proliferate• suppurative & symptomatic O.M.

Acute Otitis Media (AOM)

Acute Otitis Media

Severe AOME, pre Rupture

ACUTE OTITIS MEDIA

• Treatment– Antibiotics +/-– anti-inflammatories

CASE #1 Lisa

• HPI:– 3 yo healthy girl– 4 day hx Upper Respiratory Infection– fever last pm, crying, pulling at ears– mom using Tylenol

• Rel Hx:– daycare– no previous AOME’s

• O/E:– T 38oC– cranky– red TM’s, slight bulge

• Management….

TO TREAT OR NOT TO TREAT

• 80% AOM resolve without antibiotics• no diff in fever, otorrhea, or middle ear

effusions at 3 mos, between treatment vs nontreatment groups• only benefit: pain by day 2 is less in treated

group• therefore do not need to treat everyone….but

who??

NEED TO TREAT DUE TO HIGHER FAILURE RATE:

• age <2 ( risk meningitis)• perforated ear• temp >38.5oC

RECOMMENDATIONS if Watch & Wait

• carefully choose subjects• recheck 48 hrs, or if reliable parent, return if ,

or persistent symptoms• Advil/Motrin• treat if toxic, temp >38.5o

• F/U 4 weeks

Lisa’s Management?

Lisa’s Management

• Age>2, not too toxic, reliable parents, not perforated

• Conservative watch and wait• Reassess in office 48 hrs

CASE #2 Tom

• HPI:– 18 month boy– Upper Respiratory Tract Infection x2 days– fever & crying last pm– pulling at ears

• O/E:– 38.5oC– red bulging TM’s

• No previous AOME’s

Immediate management

• to treat or not?• with what?• how long?

Tom’s Management

• Age<2• High fever• Will treat

Etiology of AOM: Bacteria

No S. pneumoniae

36%growth

25%

GAS 3%

M. catarrhalis14%

H. influenzae

22%

Antibiotic Choice

• First Line antibiotics if no previous antibiotics in last 3 months– Amoxicillin

• For Penicillin allergic patient: – Clarithromycin– Azithromycin – (TMP/SMX- but significant resistance)

DURATION OF THERAPY

• 5-7 day treatment (3 days for azithromycin)– equal efficacy to 10 days– fewer side effects better compliance

• 10 days needed for:– age <2 – perforation & otorrhea (drainage)

Tom’s Follow Up

• In 4 wks• No symptoms• Fluid present

• 2 days after given amoxicillin for AOM• He still has fever intermittently and cries throughout the night.

• He continues to eat poorly and is fussy during the day

• His temperature is 38.7o C • The otoscopy findings follow:

Case #3 David

10% 20% 30% 0%

Trends in Resistance to S. pneumoniae in Canada

Amoxicillin 12-16% High Dose Amoxil <1% Cefuroxime 10% Cefprozil 10% Erythromycin* 10% TMP/SMX 22-28%

*Cross-resistance with other macrolides e.g., azithromycin, clarithromycinLow DE et al. Antimicrob Agent Chemother 2002;46:1295-1301, Kellner JD et al. 42nd ICAAC, San Diego, September 2002

S. PNEUMONIAE RESISTANCE

• S. pneumoniae is often cause of persistent otitis

• is cause of majority of complications • increases with antibiotic use in the 3 months

prior• Best oral agent is high dose amoxicillin (80-

100 mg/kg/day)

Trends in Resistance to H.influenzae in Canada

Amoxicillin

24-27% Cefuroxime

1% Cefprozil

10% Azithromycin

<1% Clarithromycin

2% TMP/SMX

14-19%

0% 10% 20% 30%

Zhanel G et al. JAC 2000;45:655-62, Hoban DJ et al. Clin Infect Dis 2001;32(Suppl 2):S81-93

David’s Management• Failed Treatment of Amoxil

– May be S pneumonia, H influenza• Consider 2nd line antibiotic:

– Clavulin (amoxil + clavulinic acid, neutralizes Beta Lactamase)

– 2nd generation cephalosporin – macrolide for penicillin allergic

• If quite ill, more likely S pneumonia– High dose amoxicillin

• If very ill or not sure of bug:– amoxicillin (40mg/kg/d)+ Clav/amox (40 mg/kg/d)– to provide high dose amox for pen resistant

pneumococcus, as well as the clavulinic acid for Beta Lactamase positive H influenza

PROPHYLAXIS

• works 73% of time BUT OUT OF FAVOR because it causes resistance

• amoxicillin prophylaxis study*– Showed an increase in Beta Lactamase Positive(BLP)

organisms in nasopharynx from baseline 20%- 100%– Showed an increase in penicillin resistant s. pneumoniae

(PRSP) from 0% to 25%• Use for patients too ill to go to OR for tubes, or

waiting for OR

* Brook 1995

Indications for Ventilation Tubes for Recurrent AOM

• 4 episodes AOM in 6 months, 6 in 12 months• Most ENT’s require also evidence of significant

quality of life interference– e.g. miserable, febrile, screaming with each AOM;

needing 2 courses of antibiotics to clear; developing allergies to Ab

• Reduced number needed if febrile seizures occurring, language delay with recurrent transient hearing loss

CASE #4- Ahmed

4 year old boy with speech delay– seems to understand well but does not speak clearly– only 2 known ear infections, but has a lot of colds– Doc notes fluid always present– parents are concerned that he is not joining in at

kindergarten and other children do not understand what he says

– kindergarten teacher suggests he is not ready to start school next year, even though he will be 5 in October

Otitis Media with Effusion(Chronic non-suppurative Otitis Media)

• Middle ear filled with serous or mucoid fluid, no purulence• Often present after acute otitis media is treated

appropriately with antibiotics• Most will clear within 3 months• Chronic after 3 months (COME)

Etiology of OME

• 50% sterile to culture• Eustachian tube dysfunction

Mucoid OM (Glue)

Mucoid OM

Serous OM

Serous OM

MIDDLE EAR EFFUSION CLEARANCE RATE AFTER AOM

• 2 weeks - 30%• 4 weeks - 60%• 8 weeks - 80%• 12 weeks- 90%

Management COME After 3 Months

• rarely consider trial antibiotics– boost short-term resolution by only 15% (benefit

to one in seven treated)• fix modifiable factors• consider nasal steroid if congested• control allergies• do hearing test• If fluid and hearing loss persist, esp if

speech/language delay consider tubes

Modifiable Risks for COME

• Going to sleep with a bottle or drinking from a bottle while lying on his/her back

• Smoking in the house• A wood burning stove, Cat• Day care with > 6 kids• Pacifier

VENTILATION TUBES FOR COME

• Insert if: 1. Fluid present bilaterally for more than 3 months2. Hearing level worse than 30dB threshold

hearing level3. Be more aggressive if language delay is present4. Unilateral- if present, worse than 30dB for > 6

months

Tympanostomy Tubes

• Not just there to “drain fluid”• Bypass Eustachian tube to ventilate middle ear

Complications of otitis media

Extracranial• Retropharynge

al abscess• Parapharyngeal

abscess • Lymphadentitis

Intratemporal• Mastoiditis • Petrositis

• Labyrinthitis • Facial paralysis

• Perforation

Intracranial• Extradural

abscess• Subdural abscess

• Brain abscess• Meninigitis

• Sinus thrombophlibitis

Intra-Temporal complications

PERFORATIONS

• Can reduce hearing• Risk of water entry• Risk of cholesteatoma invasion

Acute Mastoiditis

• History/Px

– AOM: 88%– fever: 83%– narrowed external auditory canal: 80%– Sagging of posterosuperior meatal wall– postauricular edema: 76%

• Microbiology:

• S. pneumoniae > P. aeruginosa > other species

Treatment

• Hospitalization for IV antibiotics• +/- Myringotomy and tube• +/- I&D subperiosteal abscess if present• +/- CT• +/- Cortical Mastoidectomy

Surgery

• Conditions for surgical treatment:– failure to respond to antibiotics– significant abscess– intracranial complications– coalescence (Bony trabeculae broken

down)= surgery– non-coalescence medical management +\-

myringotomy

Facial nerve paralysis

-Acute otitis media Treatment :-ventilation tube-rarely need mastoidectomy-consider steroids-most get complete recovery

INTRACRANIAL COMPLICATIONS

Intra-cranial Complications

Meningitis• the most common intracranial complication of

otitis media. • Tube, +/- mastoidectomy, IV Ab

Intra-cranial complications

Extradural abscess: Diagnosis– CT scans reveal the abscess

as well as the middle ear pathology.Treatment:– Mastoidectomy and

drainage of the abscess

Intra-cranial complications

It is most lethal complication of suppurative otitis media

Intra-cranial complications

Venous Sinus ThrombosisClinical picture:– Signs of blood invasion:• (spiking) fever with rigors and chills • persistent fever (septicemia).– Signs of increased intracranial pressure:headache, vomiting, and papilledema.

Otitic Hydrocephalus

• increased intracranial pressure without effect or signs of hydrocephalus

• no evidence of ventricular dilatation and focal neurologic signs are absent

• Headache, drowsiness, vomiting, blurring of vision, and diplopia are typical symptoms.

• Papilledema and sixth cranial nerve palsy are usually evident.

Otitis Hydrocephalus

• Optic atrophy can eventually develop• A normal CSF cytology and biochemistry along

with an opening pressure greater than 24 mm H2O

• very commonly associated with sigmoid sinus thrombophlebitis– not all patients with sigmoid sinus

thrombophlebitis develop otitic hydrocephalus

• Due to antibiotics, the incidence of complications has greatly declined.

• Complications are usually associated with some degree of bone destruction, granulation tissue formation, or the presence of a cholesteatoma.

• Complications arise most commonly by infection spreading by direct extension from the middle ear or mastoid cavity to adjacent structures.

Complications of Otitis Media

Complications of Otitis Media

• Patients appear more ill than expected – fever, new onset vertigo, sensorineural hearing

loss, fetid drainage, facial nerve weakness, proptotic ear

– lethargy and mental status changes • CT +/- MRI are indicated

Cholesteatoma

Cholesteatoma

• Cholesteatomas are epidermal inclusion cysts of the middle ear and/or mastoid with a squamous epithelial lining

• Contain keratin and desquamated epithelium• Misnomer because the cysts don’t contain

cholesterol• Natural history is progressive growth with erosion of

surrounding bone due to pressure effects and osteoclast activation

Acquired Cholesteatoma From Perforation

• As the edges of the Tympanic Membrane try to heal, the squamous epithelium migrates into the middle ear

Eustachian Tube Dysfunction: Progression of Cholesteatoma Pars Flacida

Mastoidectomy

• 30% recurrence/persistence in pediatrics

Conclusion

• Not all cases of acute otitis media need to be treated with antibiotics

• Amoxicillin/TMP-SMX remains first line for non recurrent AOM

• Recurrent AOM within 3 months, or recent antibiotic use, choose second line antibiotics

• High dose amoxicillin for resistant cases

• Refer to ENT and Audiology if fluid is present for 3 months

• In meantime, assess environmental issues, nasal congestion, immunization

• If you see something white coming through the tympanic mambrane, or behind it, refer to ENT in case it is a cholesteatoma

Questions?