system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 6-month-old male presents to the emergency department with his parents after his three-year-old brother hit him on the arm with a toy truck. His parents are concerned that the minor trauma caused an unusual amount of bruising. The patient has otherwise been developing well and meeting all his milestones. His parents report that he sleeps throughout the night and has just started to experiment with solid food. The patient’s older brother is in good health, but the patient’s mother reports that some members of her family have an unknown blood disorder. On physical exam, the patient is agitated and difficult to soothe. He has 2-3 inches of ecchymoses and swelling on the lateral aspect of the left forearm. The patient has a neurological exam within normal limits and pale skin with blue irises. An ophthalmologic evaluation is deferred.

Which of the following is the best initial step?
assistant
Complete blood count and coagulation panel