MRCP2-2451

MRCP2-2451

A 35-year-old man presents with a 48 hour history of swelling in his right leg. He recently returned from a trip to Asia. He has no significant medical history, does not smoke, and is not taking any medications. Physical examination is normal except for the swollen leg. An ultrasound confirms a deep vein thrombosis below the knee, and he is started on enoxaparin 1.5 mg/kg daily subcutaneously and 10 mg of warfarin. On the third day after starting warfarin, he develops dark spots on his thighs. His platelet count remains stable at 210 × 109/l. What is the most likely cause of the dark spots on his thighs?