Emergency Medicine

A 2yo girl presented to the ED for cough, fever, and increased work of breathing while on day 8 of amoxicillin for an otitis media infection. Her mother reported these new symptoms had been ongoing for 4 day and that the patient had increasing lethargy with decreasing appetite. In the ED she was found to be febrile to 102 and tachycardia. Exam notable for a non-septic appearing child in no distress with decreased right breath sounds and some subcostal retractions. Pictured is the patient's chest x-ray. A finding on the CXR prompted the second study, a lung ultrasound. What was that finding? What was seen on the ultrasound? What is this rare diagnosis? What are your next steps in management and consultants?