Pediatric Infectious Diseases - Acute Otitis Media Flashcards
(35 cards)
What are the risk factors for acute otitis media?
◦ Smoke exposure
◦ Formula feeding (vs breastfeeding)
◦ Immunization status
◦ Atopy
◦ Daycare attendance
◦ Male gender
◦ Family history: Sibling or parent w/ > 3 episodes AOM or tube surgery
◦ Onset of first episode before 6-12 months of age (earlier –> higher risk)
◦Lower socioeconomic status
◦ Race: Non-Hispanic white = risk factor (non-white children are at increased risk); Related to care seeking (diagnosis less likely if no doctor’s visit); Confounded by social factors
◦Congenital anomalies
◦Immune deficiency
What is otitis media with effusion?
◦ Middle ear fluid is sterile; no signs of acute infection
◦Antibiotics not indicated and not beneficial
What is acute otitis media?
◦Bacterial infection likely (infection of middle ear)
◦Antibiotics indicated if symptomatic
Where does acute otitis media occur?
in the middle ear - divided by tympanic membrane (ear drum), this is sterile and not exposed to outside bacterial pathogens
eustachian tubes: helps to regulate air pressure, provide drainage and protect middle ear
What are the anatomical differences in the ear in infants vs adults?
infant eustachian tube is shorter, more flexible and more horizontal vs adult
in adult the tube is angled –> better at draining
What is the pathogenesis of acute otitis media?
Ineffective aeration of middle ear space –> eustachian tube dysfunction –> Inflammation and edema of mucosal linings and narrowing of eustachian tube lumen –> Trapped air creates vacuum reversing flow of secretions, drawing fluid into middle ear –> Bacteria multiply in fluid and stimulate inflammation
Pathologic bacteria are isolated from 65-75% of well documented cases of AOM (are times fluid is still sterile even with AOM)
What are the causative pathogens of acute otitis media?
the main 3 are streptococcus pneumoniae, haemophilus influenzae, and moraxella catarrhalis
beta-lactamase production in H. flu, almost 100% of moraxella produces beta-lactamase
What are the current pneumococcal vaccines we use?
PCV15 or PCV20
these cover more serotypes
typically given at 2, 4, 6, 12-15 months
What are the clinical manifestations of acute otitis media?
◦ Otalgia (ear pain)
◦ Holding or tugging at ear
◦ Fever
◦ Irritability
◦ Poor feeding/anorexia
◦ Disrupted sleep
◦ Malaise
◦ Otorrhea (ear discharge)
◦ Sometimes asymptomatic
How do you diagnose acute otitis media?
Visualize tympanic membrane (TM):
Normal TM - Slightly concave, Pearly gray in color, Translucent, Moves in response to pressure
TM in AOM - Bulging, Cloudy or purulent effusion, Immobile
Middle ear fluid culture via tympanocentesis (infrequent)
What does the diagnosis require for acute otitis media?
acute onset, middle ear effusion (fluid collection), and symptoms of middle ear inflammation
What are the severity levels of acute otitis media?
non-severe: Mild otalgia AND Fever < 39 ̊C in past 24 hours
severe: Moderate to severe otalgia OR Fever ≥ 39 ̊C
What is the criteria for obervation vs treatment?
everyone should get treated if otorrhea is present or if they are severe
if they are non-severe and <6mo - treat
if they are non-severe and 6mo - 2yrs - bilateral we treat, unilateral observe
if they are non-severe and >/=2yrs - observe for both bilateral and unilateral
What is the initial management of acute otitis media?
Observation
◦ Deferment of antibiotics for 48 – 72 hours
◦ Watch for resolution of symptoms
◦ Provide symptomatic relief (acetaminophen or ibuprofen)
◦ Decision to observe based on: Child’s age; Diagnostic certainty; Illness severity; Assurance of follow-up
What happens if observation fails for acute otitis media?
Must ensure close follow-up and prompt access to medical care if no improvement
What to do if observation fails: Communicate with physician; Begin antimicrobial therapy; Continue symptomatic therapy
Safety-Net Antibiotic Prescription (SNAP): Parents allow 1-2 days for infection to resolve, If symptoms persist or worsen, fill prescription
What is the antibiotic treatment of acute otitis media?
Antibiotic Therapy
◦ Efficacy
◦ Resistance
◦ Oral bioavailability
◦ Middle-ear penetration
◦ Safety
◦ Tolerability
◦ Likelihood of compliance
Resistance in acute otitis media
Streptococcus pneumoniae
◦ 50% of strains are penicillin resistant - Due to alterations in penicillin binding proteins
◦ Overcome by higher concentrations of antibiotic at site (high-dose amox)
Haemophilus influenzae & Moraxella catarrhalis
◦ 40-50% of H. flu strains and almost all M. catarrhalis strains produce β-
lactamase (–> amoxicillin resistant)
◦ Overcome by addition of ß-lactamase inhibitor (such as in amox/clav)
What is the first line antibiotic for acute otitis media?
amoxicillin
80-90 mg/kg/day divided Q12H x 5-10 days - high dose!
Advantages:
◦ In middle ear, high dose amox concentrations exceeds MIC of S. pneumoniae strains resistant to penicillin (all intermediate and many highly resistant)
◦ Safe, effective, inexpensive
◦ Half-life 4-6 hours in middle ear (vs 1 hr in serum)
When do we NOT use amoxicillin?
Known resistance
Treatment failure
Amoxicillin in last 30 days
Allergy
Concurrent conjunctivitis
then we would use amoxicillin/clavulanate
What is 2nd line therapy for acute otitis media?
amoxicillin-clavulanate (augmentin)
2nd line if amoxicillin failure; 1st line if amox in last 30 days/conjunctivitis
Dose: 90 mg/kg/day amox component divided Q12H
Advantages:
◦ Additional coverage for ß-lactamase-producing organisms
Disadvantages:
◦ May be more expensive
◦ Diarrhea associated with clavulanate: Dose clavulanate at ≤ 10 mg/kg/day
What form of amoxicillin-clavulanate do we use?
600 mg amox/42.9 mg clav/5mL
Oral cephalosporins in acute otitis media
2nd line (if allergy may be 1st)
Cefpodoxime
◦ 3rd gen cephalosporin
◦ Tastes bad
◦ Better bioavailability; may work better than cefdinir but can be harder to get
Cefdinir (Omnicef®)
◦ 3rd gen cephalosporin
◦ Tastes good, but poor bioavailability
Allergy cross reactivity
Cross-reactivity highest between penicillins and 1st generation cephalosporins
◦ Much lower w/ 2nd and 3rd generation cephalosporins; cefdinir, cefuroxime, cefpodixime, ceftriaxone structurally very different from PCN
May skin test to assess
Ceftriaxone in acute otitis media
For severe cases if
◦ Oral treatment not option ◦
Initial oral treatment fails
Dosing
◦ One dose initial therapy
◦ Three doses if treatment failure
Advantages
◦ Broad spectrum
◦ As effective as 10 days of amoxicillin
◦ Compliance
Disadvantages
◦ Injection site pain
◦ Cost
◦ Avoid in <1 mo of age
◦ Cautions: Calcium co-administration, C. difficile
