Acute Bacterial Prostatitis
The most likely cause is acute bacterial prostatitis. The combination of dysuria, perineal pain, acute urinary retention over 12 hours, and a small, tender, soft prostate on digital rectal examination in a 30-year-old male is pathognomonic for this diagnosis. 1
Clinical Reasoning
The small, tender prostate on DRE is the key distinguishing feature that differentiates acute bacterial prostatitis from other causes of acute urinary retention in young men. 1, 2
- Acute bacterial prostatitis causes pelvic/perineal pain, dysuria, urinary frequency, and urinary retention, exactly matching this patient's presentation. 2
- The tender prostate on examination is a hallmark physical finding that distinguishes prostatitis from benign prostatic hyperplasia (BPH). 1
- The acute 12-hour onset rules out chronic conditions like BPH, which develops gradually over months to years and would present with an enlarged (not small) prostate. 1
Why Not Other Diagnoses
BPH is effectively excluded by three critical features:
- BPH presents with an enlarged prostate, not a small one. 3, 1
- BPH prostate is non-tender on examination. 3, 1
- BPH causes gradual onset of obstructive symptoms over months to years, not acute 12-hour retention. 1
Urethral stricture is unlikely because:
- Stricture would not cause prostatic tenderness or perineal pain. 4
- Stricture typically presents with a history of urethral trauma, instrumentation, catheterization, or prior urologic procedures, which is not mentioned here. 4, 3
- The enlarged, tender prostate finding points away from stricture disease. 3
Neurogenic bladder requires underlying neurologic disease with abnormal neurologic examination findings, particularly lower extremity dysfunction and abnormal anal sphincter tone, which are not present. 1
Immediate Management
Bladder decompression is the first priority using urethral catheterization or suprapubic cystostomy if urethral catheterization fails. 5, 6
Obtain urine cultures before starting antibiotics to determine the responsible bacteria and antibiotic sensitivity pattern. 2
Start empiric broad-spectrum antibiotics immediately after obtaining cultures:
- Outpatient oral therapy (if systemically well): Fluoroquinolone (ciprofloxacin preferred) for 4 weeks. 2, 7
- Inpatient IV therapy (if systemically ill, unable to void, unable to tolerate oral intake): Ceftriaxone plus doxycycline, or ciprofloxacin, or piperacillin/tazobactam. 2
Avoid vigorous prostatic massage during DRE as this can precipitate bacteremia in acute bacterial prostatitis. 2
Critical Pitfalls to Avoid
Do not attribute acute retention in a young man to BPH without considering infection, especially when the prostate is tender and small rather than enlarged and non-tender. 1
Do not delay catheterization in patients with acute urinary retention, as prolonged bladder distention can lead to decreased kidney function and long-term detrusor hypocontractility. 6
Monitor for post-obstructive diuresis and hematuria after bladder decompression, which are possible complications requiring fluid management. 6