Prostatitis is a topic covered in the 5-Minute Clinical Consult.

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  • Painful or inflammatory condition affecting the prostate gland with or without bacterial etiology, often characterized by urogenital pain, voiding symptoms, and/or sexual dysfunction
  • Significant impact on quality of life
  • <10% bacteria-proven infection
  • National Institutes of Health’s classification
    • Class I: acute bacterial prostatitis: symptomatic with fever, perineal pain, dysuria, and obstructive symptoms; polymorphonuclear leukocytes (PMNL) and bacteria in urine
    • Class II: chronic bacterial prostatitis: symptomatic chronic or recurrent bacterial infection with pain and voiding disturbances; PMNL and bacteria in expressed prostatic secretions (EPS), or urine after prostate massage, or in semen
    • Class III: chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)
      • Inflammatory (subtype IIIA): chronic symptoms with PMNL in EPS/urine after prostate massage or in semen
      • Noninflammatory (subtype IIIB): chronic symptoms without presence of PMNL in EPS/urine after prostate massage or in semen
    • Class IV: asymptomatic inflammatory prostatitis: incidental finding during prostate biopsy for infertility, cancer workup; presence of PMNL and/or bacteria in EPS/urine after prostatic massage or in semen
  • System(s) affected: genitourinary, renal, reproductive


  • Two million cases annually in the United States
  • Predominant age: 30 to 50 years old, sexually active; chronic is more common in those >50 years.
  • Bacterial prostatitis occurs more frequently in patients with HIV.

  • Affects approximately 8.2% of males
  • Lifetime probability of diagnosis >25%
  • Accounts for 8% of visits to urologists and 1% of visits to primary care physicians
  • Percentage of cases by class: class I: <1%, class II: 5–10%, class III: 80–90%, class IV: 10%

Etiology and Pathophysiology

  • Acute bacterial prostatitis (class I)
    • Likely, etiology from ascending urethral infection with intraprostatic reflux of infected urine into prostatic ducts, often associated with cystitis
    • Can occur after instrumentation of prostate
    • Usually, gram-negative bacteria (Escherichia coli [most common]; Proteus, Klebsiella, Serratia, and Enterobacter species; Pseudomonas aeruginosa)
    • Rarely, gram-positive bacteria (Staphylococcus aureus, Streptococcus, and Enterococcus species)
    • Confirmed staphylococcal prostatitis should warrant evaluation for hematogenous spread, including endovascular source.
    • Atypical bacteria include Chlamydia trachomatis, Trichomonas vaginalis, and Ureaplasma urealyticum.
    • Consider Neisseria gonorrhoeae or C. trachomatis in sexually active men <35 years.
  • Chronic bacterial prostatitis (class II)
    • Similar pathogens as discussed earlier
    • Often occurs as recurrent episodes of infection by same organism
    • Progression from acute to chronic prostatitis is poorly understood but could result from inadequate treatment of acute prostatitis.
  • CP/CPPS (class III)
    • Unclear etiology, possibly due to difficult-to-culture infection but noninfectious etiology also proposed
    • Inciting agent may cause inflammation or neurologic damage in or around the prostate and leads to pelvic floor neuromuscular and/or neuropathic pain.
    • No correlation between histologic inflammation of prostate and presence or absence of symptoms
    • Patients with chronic inflammation on histology have shorter time to symptomatic progression.

Risk Factors

  • Urinary tract infections
  • HIV infection
  • Prostatic calculi
  • Urethral stricture
  • Urinary catheterization: indwelling, intermittent
  • Genitourinary instrumentation, including prostate biopsy (especially in patients with prior quinolone intake), transurethral resection of prostate, cystoscopy
  • Urinary retention
  • Benign prostatic hypertrophy
  • Unprotected sexual intercourse
  • Trauma (e.g., bicycle, horseback riding)

General Prevention

Antibiotic prophylaxis for genitourinary instrumentation and prostatic biopsy

Commonly Associated Conditions

  • Benign prostatic hypertrophy
  • Cystitis
  • Urethritis
  • Sexual dysfunction, including erectile dysfunction and premature ejaculation

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