Q. A 28-year-old woman comes to her physician with complaints of frequent nosebleeds and easy bruising for the past month. She reports that she has noticed multiple small, red to purple spots on her skin. She denies any significant medical history, recent infections, or travel. Her temperature is 98.4°F (36.8°C), heart rate is 80/min, respiratory rate is 14/minute, and blood pressure is 110/70 mm of Hg. On physical examination, multiple petechiae and ecchymoses are noted on her arms and legs. There is no hepatosplenomegaly or lymphadenopathy. Laboratory findings are shown below. Peripheral blood smear is unremarkable. Coagulation studies, liver function tests, and renal function tests are within normal limits. What is the most appropriate initial step in the management of this patient?