Acute Prostatitis

Acute bacterial prostatitis is uncommon overall, but it is one of the few prostatitis presentations that is a genuine bacterial infection — most men presenting with prostatitis symptoms turn out to have chronic pelvic pain syndrome instead. E. coli causes 50–90% of cases; other Enterobacteriaceae, and sexually transmitted organisms (N. gonorrhoeae, C. trachomatis), are also implicated.

Clinical features

• UTI-type symptoms: acute dysuria, urinary frequency and urgency.
• Systemic features: fever (≥ 38°C), chills, sweats, myalgia.
• Obstructive symptoms: weak stream, dribbling, hesitancy, urinary retention.
• Prostatic involvement: pelvic or perineal pain; an enlarged, exquisitely tender prostate on gentle digital rectal examination — avoid vigorous prostate massage, which can acutely worsen the infection and is contraindicated while acute infection is suspected.
• Also assess for costovertebral angle tenderness (pyelonephritis is an important differential) and suprapubic fullness (urinary retention).

Risk factors: recent genitourinary instrumentation (transrectal prostate biopsy, catheterisation, cystoscopy), unprotected anal/vaginal intercourse, indwelling catheter, phimosis, and benign prostatic hyperplasia.

Acute bacterial prostatitis following genitourinary instrumentation (e.g. transrectal ultrasound-guided prostate biopsy) is often associated with sepsis and multidrug-resistant Gram-negative bacteria — seek expert advice in this setting.

Investigations

• Urine MCS (midstream); blood cultures, lactate, and FBC if septic or with significant comorbidity.
• Testing for N. gonorrhoeae/C. trachomatis if an STI is suspected or urethral discharge is present.
• Imaging (transrectal ultrasound, CT, or MRI) if a prostatic abscess is suspected (immunocompromise, predisposition to bacteraemia, or clinical worsening despite treatment) — an abscess can complicate prostatitis and may need drainage.
• PSA and inflammatory markers (CRP/ESR) are of limited value — not specific enough to guide management in acute prostatitis.
• Do not biopsy the prostate during acute infection — risk of seeding infection to adjacent structures, and it is unnecessarily painful.

Complications

Sepsis, prostatic abscess, epididymitis, and pyelonephritis. Around 5–10% of men progress to chronic bacterial prostatitis, and at least 10% develop chronic pelvic pain syndrome even after successful treatment.

Management

Non-severe (afebrile, no systemic features, no sepsis/septic shock):

• Trimethoprim 300mg orally daily for 2 weeks, OR
• Cefalexin 500mg orally 6-hourly for 2 weeks.
• If resistant to both and the pathogen is susceptible: ciprofloxacin 500mg orally 12-hourly for 2 weeks, OR norfloxacin 400mg orally 12-hourly for 2 weeks.
• Confirm resolution with repeat urine culture 1 week after completing treatment.

Severe (fever ≥ 38°C, systemic features, or sepsis/septic shock):

• Gentamicin IV plus either amoxicillin 2g IV 6-hourly or ampicillin 2g IV 6-hourly.
• If gentamicin is contraindicated: ceftriaxone 1g IV daily, or cefotaxime 1g IV 8-hourly, as monotherapy.
• Penicillin hypersensitivity: gentamicin alone as empirical therapy.
• Total duration (IV + oral) is usually 4 weeks.
• Confirm resolution with repeat urine culture 1 week after completing treatment.