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PATIENT 
Mr. C is a 57-year-old man who complains of dysuria that started suddenly 5 days ago. He reports the pain radiates to his low back and perineum. He has felt “achy” and had chills but has not measured his temperature. He denies any penile discharge, rash, nausea, vomiting, or flank pain. He has had more difficulty urinating with a weaker urinary stream for the past few days. He also feels some dizziness upon standing.
At this point what is the leading hypothesis, what are the active alternatives, and is there a must not miss diagnosis? Given this differential diagnosis, what tests should be ordered?
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PRIORITIZING THE DIFFERENTIAL DIAGNOSIS
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Mr. C is experiencing dysuria with radiation to the perineum and associated urinary hesitancy. His sex and the radiation of the pain are pivotal points in this history, suggesting acute prostatitis. Acute prostatitis is a life-threatening cause of dysuria. Urosepsis is another must not miss diagnosis given the systemic symptoms and orthostasis. The absence of penile discharge is important in limiting the list of diagnoses. Other common but less dangerous alternatives include urethritis from an STI and complicated cystitis. Pyelonephritis should also be considered. Table 16-4 lists the differential diagnosis.
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Mr. C is sexually active with several female partners and does not use condoms or other barrier protection. He has no active medical problems but has noted nocturia over the past few months.
Temperature is 38.2°C, pulse 80 bpm, RR 12 breaths per minute, BP 142/78 mm Hg, and orthostatic vital signs are negative. Abdominal exam demonstrates suprapubic tenderness without rebound or guarding and the absence of CVA tenderness. Genital exam is normal, but there is tenderness on gentle prostate exam without any palpable masses.
Is the clinical information sufficient to make a diagnosis? ...