1) Previously healthy 7 year old boy with fever, sore throat and rash for 2 days
Differential diagnosis
>>Viruses
▫Epstein-Barr virus (commonly seen in teens)
▫Herpes simplex virus
▫Adenovirus, influenza, (parainfluenza, RSV, coronavirus)
▫Enteroviruses (coxsackie)
>>Bacteria (rarely see these)
▫Corynebacterium diphtheriae
▫Archanobacterium hemolyticum
▫(Neisseria gonorrheae)

Management
>>Diagnosis
▫Rapid antigen detection test has high specificity, but limited sensitivity (if clinically likely, take culture even if test neg)
▫Throat swab for culture should always be taken prior to initiating antibiotics
>>Treatment (betalactams are drug of choice)
▫Penicillin V x 10 days (amoxicillin is an alternative)
▫Macrolides for penicillin allergic (macrolide resistance rates among S. pyogenes isolates in Canada 10-15%)
>>>>azithromycin (type of macrolide) acts quickly & tastes good, but increased resistance & long t1/2

2) Generally healthy 2 year old girl with fever (39.3o C) and ear ache x 24 hours
•What else do you want to know?
>>hx abx of use, recurrence of otitis, exposure/contact w/ sick pts, vaccinations
>>>>if get otitis after full vaccinations, more likely has resistant strain
•What are the likely pathogens?
>>h influenza, s pneumoniae, moraxella - top 3 to rmb
•What empiric therapy would you give (if any)?
>>can wait & see x48h - based on pain, T, age, background hx
>>amoxicillin - drug of choice - for now recommendation is high dose
•No prior episodes of AOM
•Immunizations up-to-date (including Prevnar)
•No recent antibiotics
•Two older siblings (4, 5 years old), both healthy
•Attending daycare
•Many children in day care with URTIs

Pathogens of acute otitis media
•Bacteria
▫Streptococcus pneumoniae (25% to 40%)
▫Non-typeable Haemophilus influenzae (10% to 30%)
▫Moraxella catarrhalis (5% to 15%)
▫Other less commonly seen pathogens include group A Streptococcus, S. aureus (3% to 5%)
•Viruses account for up to 20% of acute otitis media cases (bacterial cultures negative)

Natural history
>>Approximately 80% resolve without specific therapy
▫S. pneumoniae (least likely to resolve, which is why target with amoxi)
▫Non-typeable Haemophilus influenzae
▫Moraxella catarrhalis
>>Factors associated with lack of spontaneous resolution
▫Age < 2 years of age
▫Recurrent otitis media
▫Severe disease
▫Malnutrition or other immunocompromised states

Antibiotic therapy
>>First line (high dose amoxi) - Amoxicillin 75-90 mg/kg/day divided BID
>>Second line - Cefprozil, Cefuroxime, Ceftriaxone, Azithromycin, Clarithromycin
>>Treatment failure - if no sx improvement after 2-3d of initial therapy (Amoxicillin-clavulanate 90 mg/kg/day (amoxil component) divided BID x 10 days)
>>>>if no response to amoxi-clavu (Ceftriaxone 50 mg/kg/day for 3 doses) - consider need for tympanocentesis

Mother calls after 48 hours; still febrile, still having ear pain
•Why has she not responded? (Haven’t taken the antibiotics, Inadequate dose prescribed, Alternate diagnosis, Resistant S. pneumoniae , Haemophilis influenzae …)
•What will you do now?
>>Treatment options
▫Amoxicillin-clavulanate, with high dose amoxicillin component (80-90 mg/kg/d)
▫Cefuroxime (or cefprozil)
▫IM ceftriaxone x3 days
▫Macrolide may be OK but resistance relatively common

Watchful waiting criteria
>>Child is older than 6 months
>>No underlying conditions of concern
▫Immunodeficiency
▫Chronic cardiac or pulmonary disease
▫Anatomic abnormalities of head/neck
▫History of complicated otitis media
▫Down syndrome
>>Non-severe illness
▫Otalgia appears mild & fever < 39.0oC without antipyretics
>>Parents capable of recognizing signs of worsening disease and can readily access medical care