A 19 year-old man presents with a 2 day history of "his fingers turning black" and a 3-4 month history of recurrent painful lumps on his lower legs and a persistent net-like rash over the calves and ankles which does not fade with pressure (see pictures, below). His only other symptoms are fatigue and intermittent low grade fevers. He denies abdominal pain, hematuria, dyspnea, chest pain or focal neurological deficits. Six weeks before symptom onset, he had a self-limited sore throat.
What is your diagnosis, what test or tests would you order to confirm your suspicions, and what treatment, if any, do you recommend?
In order to receive credit, please email your answers to smithj@etsu.edu.