A 62-year-old man presents with an acutely painful, swollen right knee that is warm and tender. He is febrile at 38.2 degrees Celsius and unable to bear weight. What is the most appropriate immediate investigation or management?APrescribe oral NSAIDs and review in 1 weekBArrange urgent joint aspiration for microscopy, Gram stain and cultureCOrder a routine rheumatology outpatient referral for suspected goutDStart oral Allopurinol immediatelyESend serum urate level and await the result before actingCheck my answer