An 8-month-old previously healthy boy presents to the ED with fever and nystagmus. He has been having cough, congestion, and rhinorrhea for about 1 week. Over the past 2 days, he has been persistently febrile despite antipyretics. Today in his pediatrician's office, he was diagnosed with bilateral acute otitis media (AOM). However, the physician noted horizontal nystagmus in the child and sent him to the ED for further evaluation. Physical examination reveals a well-appearing, interactive, fair-skinned boy who has light, cream-colored hair. He has bilateral otitis media with profuse otorrhea. Complete neurologic evaluation yields normal results with the exception of intermittent, right-sided, jerky nystagmus. Initial laboratory results show a normal CBC and serum electrolyte concentrations. A CSF examination does not show any evidence of infection, and a head CT scan demonstrates bilateral middle ear and mastoid effusions but no acute intracranial process. An EEG is read as normal. The patient is seen by an ophthalmologist for further investigation of the cause of his nystagmus, and the findings on the funduscopic examination lead to a clinical diagnosis. A 3-year-old girl presents to the ED with a history of intermittent swelling and bleeding from her gums for the past 2 months. She has no history of bleeding from any other site. Yesterday she had one episode of hematemesis and appeared pale. There is no fever, cough, runny nose, dental caries, or trauma to the face. Past medical history and family history, including for bleeding disorders, is negative. She is not taking any medications. On examination, her temperature is 37.0°C, heart rate is 132 beats/min, respiratory rate is 26 breaths/min, and blood pressure is 113/52 mm Hg. She appears pale and anxious. A swelling is apparent on her left lower gum, with active bleeding near the second molar tooth and mild swelling of …