You are caring for a 4 year old girl who presents with acute…

You are caring for a 4 year old girl who presents with acute onset of epistaxis and a noticeable petechial rash. Previously healthy, but parents do report the whole family had a cold about 2 weeks ago. CBC reveals a normal hemoglobin and hematocrit with a platelet count of 4,000. Peripheral smear is normal except for the lack of platelets and the ones that are seen are large. What is the most likely diagnosis?

A 10-year-old boy is brought to the emergency department by…

A 10-year-old boy is brought to the emergency department by his parents because he has had worsening cough, fever, and difficulty breathing over the past three days. The patient was evaluated by his pediatrician five days ago when the symptoms began and received a diagnosis of influenza B virus. Supportive care was recommended for treatment. Temperature is 39.4°C (103.0°F). The patient appears ill. Oxygen saturation is 86% on room air, and 2 L/min of oxygen via nasal cannula is administered. A chest x-ray study is shown. Which of the following is the most likely causal agent?