MSFinals-4496
A 3-year-old girl with several small bruise-like lesions is brought to the emergency department by her father. He reports first noticing these lesions on his daughter’s arm when dressing her three days ago, despite no obvious preceding trauma. The bruising does not appear to be spreading.
Notably, the child had mild cough and fever symptoms two weeks ago, though has now recovered.
On examination, the child appears well in herself and is playing with toys. There are 3 small petechiae on the patient’s arm. The examination is otherwise unremarkable.
What would be an indication for bone marrow biopsy, given the likely diagnosis?