Question category: Rheumatology
A 58 year old male presents with a one month history of exertional dyspnoea and abdominal pain. He is fatigued and is complaining of myalgia and headache. He is also complaining of joint pain and is complaining of numbness of his feet. On examination there is evidence of purpura on his shins. His blood tests reveal renal impairment. What is the most likely diagnosis?