CAUSES
. Bacterial
. Ascending infection through urethra
. Refluxing urine into prostate ducts
. Direct extension or lymphatic spread from rectum
. Hematogenous spread
. Calculi serving as nidus for infection
. Aerobic gram negative bacteria ( Escherichia coli , Pseudomonas , Klebsiella , Proteus , N. gonorrhea, Enterobacteriaceae , Burkholderia
pseudomallei )
. Miscellaneous - Chlamydia trachomatis
. Gram positive bacteria ( Streptococcus faecalis, Staphylococcus aureus )
. Organisms suspected, but unproven ( Staphylococcus epidermidis , Micrococci, non-group D streptococcus, Diphtheroids)
. Uncommon: Mycobacterium tuberculosis ,
parasitic, Mycoses (blastomycosis, coccidioidomycosis, cryptococcus, histoplasmosis, paracoccidiomycosis,
candidiasis)
. Nonbacterial
. Non-relaxation (spasm) of the internal urinary
sphincter and pelvic floor striated muscles leading to increased prostatic urethral pressure and intraprostatic urinary reflux, leading theory
. Ureaplasma, Trichomonas vaginalis , and Chlamydia postulated, but not proven
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DIFFERENTIAL DIAGNOSIS
β’ Cystitis (bacterial, interstitial)
β’ Urethritis
β’ Pyelonephritis
β’ Malignancy
β’ Obstructive calculus
β’ Foreign body
β’ Acute urinary retention
RECTAL EXAM. - ENLARGED, TENDER PROSTATE
PROSTATIC FLUID EXAM - TAKEN BY PROSTATIC MASSAGE, FOR C / S TEST
LABORATORY
. Fractional urine examination (4 glass test). (Note: Avoid vigorous massage of the prostate in acute bacterial prostatitis secondary to induced iatrogenic bacteremia.)
. Specimen collection
- VB1: Initial 10 mL urine from urethra
- VB2: Next 200 mL discarded, then midstream from bladder
- EPS: Then, expressed prostate secretion
- VB3: Urine after prostate massage.
. Specimen handling
- Urinalysis, culture, sensitivities, gram stain on all samples
- pH of EPS
- Bacterial antigen-specifi c IgA and IgG levels in EPS
- Wet mount of EPS
. Interpretation
- Over 10-15 white cells per high powered fi eld suggests bacterial prostatitis
- Macrophages containing fat (oval bodies) suggests bacterial prostatitis
- Positive culture in EPS or VB3 but not VB1 or VB2 diagnostic of bacterial prostatitis
- In acute bacterial prostatitis, serum and EPS fluid bacterial antigen-specific IgA and IgG can be detected immediately after the onset of infection.
Level decline over 6-12 months after successful antibiotic therapy.
- Bacteria count generally less in chronic prostatitis
- In chronic bacterial prostatitis, no serum IgG elevation is seen, whereas EPS fluid IgA and IgG levels are increased. With antibiotic therapy, IgG levels
return to normal in several months, but IgA levels remain elevated for 2 years.
- Prostatic fluid alkaline in chronic bacterial prostatitis
- White blood cells with a negative culture (although false negative cultures are not uncommon) suggests non-bacterial prostatitis
- No abnormal findings with chronic prostatitis without inflammation (this misnomer refers to patients with symptoms such as perineal pain, ejaculatory
pain, and lower abdominal pain but who do not have inflammatory changes on lab studies)
β’ PSA level increased with acute prostatitis. (Do not order for prostate cancer screening until at least one month after prostatitis treated.)
IMAGING
β’ CT or ultrasound, if malignancy or abscess suspected
β’ Transrectal ultrasound (if prostatic calculi or abscess suspected)
DIAGNOSTIC PROCEDURES
β’ Needle biopsy or aspiration for culture
β’ Urodynamic testing (prostatodynia)
β’ Cystoscopy (in persistent nonbacterial prostatitis to rule out bladder cancer, interstitial cystitis)