An 18-Year-Old Woman Comes to the Emergency Department for Evaluation

An 18-year-old woman comes to the emergency department for evaluation of a rash.  The patient developed mild aches involving her knees and ankles 2 days ago.  Before going to sleep last night, she noticed purplish spots around her right knee.  Today, the rash involves both of the lower extremities.  She has had no fever, weight loss, sore throat, abdominal pain, vomiting, or diarrhea.  The patient has no chronic medical conditions and takes no medications.  Temperature is 37 C (98.6 F) , blood pressure is 146/90 mm Hg, pulse is 90/min, and respirations are 20/min.  Cardiopulmonary examination is unremarkable.  The patient has pain with passive range of motion of the knees and ankles.  Skin examination is seen in the exhibit.Laboratory results are as follows: Histologic examination of the rash is most likely to show which of the following?

A) Abundant intravascular fibrin without inflammatory cells
B) Obliterative endarteritis with lymphocytes and plasma cells
C) Perivascular necrotizing granulomas with eosinophilic infiltration
D) Small vessels damaged by perivascular neutrophil accumulation
E) Vessels with transmural granulomatous infiltration and fragmentation of elastic fibers