Review Question - QID 213502

A 36-year-old woman is brought to the emergency department for acute onset chest pain. She just returned from Japan 2 days ago and reports 7/10 chest pain that is worse with deep inspirations. Her past medical history is unremarkable. She currently takes oral contraceptives for birth control. A computed tomography scan is performed and demonstrates an embolus at the right lung. She is subsequently started on intravenous heparin with a transition to an oral medication at discharge. Three days after discharge, she returns to the emergency department for skin findings shown in Figure A. She denies any fever, flu-like symptoms, trauma, or abnormal contact. What is the most likely explanation for this patient’s condition?