A 7-year-old boy is brought to the clinic by his mother because of persistent discharge from his right ear for the past 2 months. She reports that the discharge is foul-smelling and sometimes blood-tinged. The child denies fever but occasionally complains of difficulty hearing in that ear. He had multiple episodes of acute otitis media in early childhood. Otoscopic examination reveals a perforated tympanic membrane with purulent discharge. There is no mastoid tenderness or swelling. What is the most likely causative organism in this patient?

A 7-year-old girl presents to the emergency department with fever, left ear pain, and swelling behind her ear for the past three days. She had acute otitis media (AOM) one week ago, which was treated with amoxicillin, but her symptoms have worsened. On examination, her left auricle is pushed forward, and there is tenderness, erythema, and swelling over the mastoid process. A CT scan confirms mastoid air cell opacification with bony destruction. Which of the following is the most serious potential complication of her condition?

A 4-year-old boy is brought to the emergency department by his parents due to right ear pain, swelling behind the ear, and fever for the past three days. History of Present Illness: The boy developed acute otitis media (AOM) one week ago and was prescribed oral amoxicillin, but his parents discontinued the medication after three days when his symptoms seemed to improve. Over the past three days, his ear pain worsened, and his parents noticed redness and swelling behind his right ear. He has been irritable, refusing to eat, and has had a persistent fever of 39.2°C (102.6°F). They also noticed that his right ear appears to be pushed forward. Past Medical History: Recurrent acute otitis media (AOM) (3 episodes in the past six months) No known allergies Vaccinations are up to date Family & Social History: No family history of recurrent ear infections or hearing loss Attends daycare (frequent upper respiratory infections) Physical Examination: General: Febrile (39.2°C / 102.6°F) Irritable but alert Head & Neck: Right postauricular erythema, swelling, and tenderness Auricle is displaced anteriorly and downward No fluctuance or skin breakdown over the mastoid region Otoscopy: Bulging, erythematous tympanic membrane on the right Purulent otorrhea present Left ear is normal Neurological Examination: Cranial nerves intact (no facial weakness) No signs of meningeal irritation (no neck stiffness, negative Kernig and Brudzinski signs) Diagnostic Workup: Laboratory Tests: White blood cell (WBC) count: 15,200/mm³ (elevated, suggests infection) C-reactive protein (CRP): Elevated Erythrocyte sedimentation rate (ESR): Elevated Imaging: CT scan of the temporal bone: Opacification of mastoid air cells Bony destruction of the mastoid process No evidence of intracranial extension What is the most serious potential complication of this condition if untreated?