Typical AOM pathogens (Streptococcus pneumoniae · Haemophilus influenzae · Moraxella catarrhalis · Streptococcus pyogenes — same spectrum as acute otitis media; polymicrobial infection common (AAP Red Book, ESPID, pediatric ENT literature))
Clinical context (Post-auricular erythema/swelling/tenderness with protrusion of pinna following or concurrent with AOM; hospitalized for IV antibiotics, pain control, and ENT assessment — no subperiosteal abscess or intracranial extension on imaging)
First-line therapy
Ceftriaxone • i.v. • 50–75 mg/kg/day • 1×/day
Max 2000 mg/day · Duration: 10–14 days · First-line empiric IV therapy for uncomplicated acute mastoiditis — covers S. pneumoniae, H. influenzae, M. catarrhalis, and most streptococci; once-daily dosing (AAP Red Book, ESPID, pediatric ENT protocols)
• Diagnosis: complication of AOM with post-auricular erythema, swelling, tenderness, and/or auricular protrusion; may have fever, otorrhea, mastoid tenderness on otoscopy — distinguish from otitis externa and cellulitis without middle-ear disease (AAP Red Book, ESPID, NICE).
• Hospitalization required for all suspected acute mastoiditis — initiate IV antibiotics after blood culture (and middle-ear culture if myringotomy performed); do not manage uncomplicated cases as outpatient oral therapy alone (AAP, ESPID, pediatric ENT consensus).
• Ceftriaxone 50–75 mg/kg/day IV once daily (max 2 g/day): standard first-line empiric regimen when no subperiosteal abscess or intracranial complication — use 75 mg/kg/day at upper range for severe systemic illness within this variant (AAP Red Book, ESPID).
• Urgent pediatric ENT/otolaryngology consult at diagnosis — assess need for myringotomy (± tympanostomy tube) for middle-ear drainage and culture; uncomplicated cases may respond to antibiotics ± myringotomy without mastoidectomy (AAP, ESPID, pediatric ENT guidelines).
• Obtain contrast-enhanced CT temporal bone when diagnosis uncertain, no clinical improvement at 48–72 h, suspected subperiosteal collection, or surgical planning needed — MRI preferred if intracranial complication suspected (AAP, ESPID, IDSA CNS infection principles).
Enter weight on Kids to calculate doses
Cefotaxime • i.v. • 50–50 mg/kg/dose • 4×/day
Max 2000 mg/dose · Max 8000 mg/day · Duration: 10–14 days · Alternative IV beta-lactam — 50 mg/kg/dose IV 3–4×/day (max 2 g/dose); use when ceftriaxone allergy, hyperbilirubinemia in neonate, or clinician preference for q6h cephalosporin (AAP Red Book, Nelson's)
• Cefotaxime: ceftriaxone allergy or intolerance, neonatal hyperbilirubinemia concern, or preference for divided-dose third-generation cephalosporin — 50 mg/kg/dose IV q6h (max 2 g/dose) (AAP Red Book, Nelson's).
• Oral step-down (amoxicillin/clavulanate): afebrile ≥24–48 h, decreasing post-auricular swelling, tolerating oral antibiotics, and no imaging evidence of abscess or intracranial extension — complete total 2–3 week course (AAP, ESPID).
• Add clindamycin or vancomycin when MRSA risk: purulent otorrhea with prior MRSA, healthcare exposure, high local MRSA prevalence, severe toxicity, or clinical failure at 48–72 h on cephalosporin monotherapy (IDSA SSTI, AAP Red Book).
• Myringotomy ± tympanostomy tube: middle-ear effusion/purulence — obtain culture; often performed at diagnosis by ENT to decompress middle ear and guide therapy (AAP, ESPID, pediatric ENT).
• Escalate to severe/complicated variant if CT shows subperiosteal abscess, sigmoid sinus thrombosis, epidural abscess, meningitis, or brain abscess — do not continue uncomplicated pathway alone (AAP, ESPID, IDSA CNS principles).
Enter weight on Kids to calculate doses
Clinical notes
• Complication of AOM: acute mastoiditis develops when infection spreads from middle ear to mastoid air cells — classic findings are post-auricular erythema, swelling, tenderness, and pinna protrusion with concurrent or recent otitis media; bilateral disease is rare and should prompt alternate diagnosis workup (AAP Red Book, ESPID, NICE).
• Imaging: contrast-enhanced CT temporal bone for suspected subperiosteal abscess, surgical planning, or lack of improvement at 48–72 h; MRI brain with venography when intracranial extension suspected (epidural abscess, meningitis, sigmoid/lateral sinus thrombosis, brain abscess, Bezold abscess) — MRI more sensitive for early intracranial complications (AAP, ESPID, IDSA CNS infection principles).
• Surgical indications: myringotomy (± tube) for middle-ear drainage at presentation in most cases; cortical mastoidectomy indicated for subperiosteal abscess, coalescent mastoiditis with bony erosion, cholesteatoma, failed medical therapy at 48–72 h, or intracranial extension — combined with IV antibiotics (AAP, ESPID, pediatric ENT guidelines).
• MRSA coverage: add vancomycin (or clindamycin if susceptible) when prior MRSA, purulent infection with MRSA risk factors, severe sepsis, healthcare-associated infection, or failure on beta-lactam at 48–72 h; obtain cultures from blood, middle ear, and surgical specimens (IDSA SSTI, AAP Red Book).
• IV duration and oral step-down: continue IV until afebrile ≥24–48 h with improving post-auricular findings and tolerated oral intake; total antibiotic course typically 2–3 weeks (uncomplicated) — longer if abscess drained or intracranial involvement. Urgent ENT consult for all cases. Intracranial red flags: severe headache, vomiting, altered mental status, cranial nerve palsy, nuchal rigidity, focal neurologic deficit, or papilledema — emergency imaging and neurosurgical/ENT co-management (AAP, ESPID, NICE serious illness principles).
• AAP Red Book — Mastoiditis and complications of otitis media (2024)
• ESPID — Acute otitis media and mastoiditis guidance (2024)
