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  PROSTATITIS 


General Goal: To know the major cause(s) of this disease, how this disease is acquired, and the major manifestations this disease.

Specific Educational Objectives: The student should be able to:

1. recite the common means by which this disease is acquired and identify the major disease manifestations.

2. identify the various types of prostatitis based on clinical presentation and testing.

3. describe which forms of prostatitis are most amenable to treatment. Know which patients with prostatitis that you should NOT obtain prostatic secretions and why.

Reading: Mosby's Color Atlas and Text of Infectious Diseases by Christopher P. Conlon and David R. Snydman. pp.132-136.

Lecture: Dr. Neal R. Chamberlain

References:  JAMES J. STEVERMER, M.D., M.S.P.H., and SUSAN K. EASLEY, M.D. Treating Prostatitis. Am Fam Physician 2000;61:3015-22,3025-6.


Overview

Prostatitis is an inflammation of the prostate gland. The term prostatitis describes a wide spectrum of disorders ranging from acute bacterial infection to chronic pain syndromes. Prostatitis describes a wide number of maladies with variable etiologies, prognoses and treatments. Unfortunately, these conditions have not been well studied, and most recommendations for treatment are based primarily on case series and anecdotal experience. Prostatitis can be a challenging condition to treat.

Etiology

Etiology depends on the classification of the prostatitis. However, most of the cases of prostatitis due to an infection are the result of gram-negative bacteria. Sixty percent of the cases of acute bacterial prostatitis (ABP) are due to Escherichia coli (most common cause). The following can also cause ABP Klebsiella sp., Proteus sp., Pseudomonas aeruginosa, and Enterococcus sp. Occasionally Chlamydia sp., Staphylococcus aureus, or anaerobes such as Bacteroides sp. can cause ABP.

The overwhelming majority of infections are due to Gram-negative rod shaped bacteria. Twenty percent of patients may have two or more different kinds of Gram-negative bacilli present in the prostate.

Manifestations

Acute Bacterial Prostatitis (ABP): Because acute infection of the prostate is often associated with infection in other parts of the urinary tract patients may also have symptoms consistent with cystitis or pyelonephritis. Fever, shaking chills, perineal pain, low back pain, dysuria, urinary frequency and urgency, decreased libido or impotence, painful ejaculation, and varying degrees of bladder outflow obstruction. Physical exam reveals a warm, very tender, diffusely enlarged, irregular, and indurated prostate. A vigorous digital examination of the prostate should be avoided because it can induce bacteremia or cause the bacteremia, if present, to be worse.

Chronic Bacterial Prostatitis (CBP): CBP is a common cause of recurrent urinary tract infections in men. Symptoms are quite variable and include irritative voiding symptoms, pain in the back, testes, epididymis or penis, low-grade fever, arthralgias, and myalgias. Many patients are asymptomatic between episodes of cystitis. Signs may include urethral discharge, hemospermia and evidence of secondary epididymo-orchitis. Usually the prostate is normal on digital rectal examination. Refer to table below for more help in diagnosis.

Chronic Nonbacterial Prostatitis/Chronic Pelvic Pain Syndrome- Inflammatory and noninflammatory (CNP/CPPS): In men going to urologic referral centers more than 90% meet the criteria for CNP/CPPS. Patients experience painful ejaculation, pain in the penis, testicles, or scrotum, low back pain, rectal or perineal pain, or even pain along the inner aspects of the thighs. They oftentimes have irritative or obstructive urinary symptoms and decreased libido or impotence. They usually do not have recurrent urinary tract infections. Usually the physical exam is unremarkable however they may have a tender prostate.

Asymptomatic Inflammatory Prostatitis: This new category was added because of the widespread use of the prostate-specific antigen (PSA) test. It is defined at an incidental observation of leukocytes in prostatic secretions or tissue obtained during evaluation for other disorders, (e.g., leukocytes present in prostate biopsies obtained due to elevated PSA). Symptomatic prostatitis can elevate the PSA test to abnormal levels. Patients being evaluated for other prostatic diseases may have prostatitis on biopsy.

Epidemiology

Pathogenesis

How acute bacterial prostatitis occurs is still largely unknown. The strains of E coli that cause pyelonephritis appear to use the same virulence factors (P pili) to cause prostatitis. Two main mechanisms for acute bacterial prostatitis have been proposed.

Mechanisms involved in chronic forms of prostatitis are just beginning to be proposed and appear to result from an interaction between psychological factors and dysfunction in the immune, neurological and endocrine systems.

Acute prostatitis: Inflammation of the prostate. Numerous PMN's in and around the acini, associated with intraductal desquamation, cellular debris and tissue invasion by lymphocytes, plasma cells, and macrophages. Microabscesses may occur and develop into large abscesses.

Chronic forms of prostatitis: Less inflammation of the prostate. Plasma cells and macrophages infiltrate in and around the acini.

Diagnosis

Prostatitis is not easily diagnosed or classified. Patients often present with varied and nonspecific symptoms. The physical examination is frequently not useful. If the history and physical suggest prostatitis the four-glass test (Stamey-Meares four glass localization method) or the pre- and postmassage test (PPMT) may be used to aid in diagnosis.

Even though the Stamey-Meares method is the gold standard it has not been assessed for its usefulness in the diagnosis or treatment of prostatitis. The expression of prostatic secretions required to perform this test can be difficult and uncomfortable. The test is cumbersome and expensive which may explain why many primary care physicians and urologists infrequently use it. In most cases, empiric antibiotic therapy is reasonable whether or not the diagnostic test proves a bacterial cause. Prostate massage to express prostatic secretions should NOT be performed in patients with ABP because massaging the prostate can cause bacteremia.


Interpretation of Two Diagnostic Tests for Prostatitis

Diagnostic test

Test components

Pre- and postmassage test (PPMT)

Midstream urine culture*

Expressed prostatic secretions‡

Stamey-Meares four-glass test

Premassage urine culture*

Premassage urine microscopy†

Postmassage urine culture‡

Postmassage urine microscopy†

Type of prostatitis

Test findings

Acute bacterial prostatitis

+

+

Avoid massage in ABP

Avoid massage in ABP

Chronic bacterial prostatitis

-

±

+

+

Chronic nonbacterial prostatitis/ CPPS­inflammatory

-

±

-

+

Chronic nonbacterial prostatitis/ CPPS­noninflammatory

-

-

-

-

Asymptomatic inflammatory prostatitis

±

±

+

+

+ = Positive; - = negative; ABP = acute bacterial prostatitis; CPPS = chronic pelvic pain syndrome.
*--Negative result is no bacterial growth. Positive result is growth of a single bacterial species (>100,000 colony forming units per mL).
†--Negative result is <10 white blood cells per high-power field. Positive result is >10 to 20 white blood cells per high-power field.
‡--Positive result is significant bacteriuria in the postmassage specimen (any bacteria if the premassage urine is sterile or colony count per mL is at least 10 times greater than premassage count).


Two different classification systems are currently in use in the management of prostatitis. The comparison of the two different systems can be seen below.

Classifications of Prostatitis

Classic system*

NIH proposal†

Acute prostatitis

I

Acute prostatitis

Chronic bacterial prostatitis

II

Chronic bacterial prostatitis

Chronic nonbacterial prostatitis

IIIa

Chronic nonbacterial prostatitis/chronic pelvic pain syndrome ­inflammatory

Prostadynia

IIIb

Chronic nonbacterial prostatitis/chronic pelvic pain syndrome­ noninflammatory

--

IV

Asymptomatic inflammatory prostatitis

*--Information from Stamey TA. Pathogenesis and treatment of urinary tract infections. Baltimore: Williams & Wilkins, 1980.
†--Proposed at the Chronic Prostatitis Workshop, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md., December 7-8, 1995 and retrieved on April 20, 2000, from http://www.niddk.nih.gov/health/urolog/pubs/cpwork/cpwork.htm.

Therapy

Acute Bacterial Prostatitis (ABP): Patients respond well to most antibiotics primarily because the prostate is inflamed. Antibiotics that are used include: tetracycline, trimethoprim-sulfamethoxazole, or a quinolone. Men that are likely to get sexually transmitted diseases should be treated with an antibiotic that also covers Chlamydia sp. The duration of the therapy is not very well studied however; most experts recommend 3-4 weeks of treatment. Longer courses of therapy may be needed. Unfortunately, most (65 percent of primary care physicians and 40 percent of urologists) only treat for 2 weeks and as a result see more treatment failures. If the patient is extremely ill (septic) they should be hospitalized and receive parenteral antibiotics. Treatment is similar to treatments for sepsis (e.g., ampicillin and gentamicin with ciprofloxacin or levofloxacin to be used in patients that are allergic to ampicillin or gentamicin). Severe obstructions may require suprapubic catheters. Supportive measures include antipyretics, analgesics, hydration, and stool softeners.

Chronic Bacterial Prostatitis (CBP): The cure rate with antibiotics ranges from 33 to 71% depending of the study and the antibiotics used. Initially treatment with trimethoprim-sulfamethoxazole or fluoroquinolones should be considered for at least 4-8 weeks. Recurrent infections may require antibiotic therapy for 3-6 months.

Chronic Nonbacterial Prostatitis/Chronic Pelvic Pain Syndrome- Inflammatory and noninflammatory (CNP/CPPS): Treatment is challenging and very difficult. Failures are commonplace (66%). The following have success in some patients.

  • α-Blockers (e.g., tamsulosin [Flomax],alfuzosin [Uroxatral],terazosin [Hytrin])
  • Anti-inflammatory medications
  • Finasteride (Proscar),pentosan polysulfate (Elmiron),and phytotherapies (e.g., cernilton, quercetin)
  • Nonpharmacologic therapies (biofeedback, pelvic floor training, thermal treatments)
  • Repeat treatment if relief is noted.
  • Combine therapies if partial relief is noted.

Asymptomatic Inflammatory Prostatitis: No treatment is recommended.

Send comments and email to Dr. Neal R. Chamberlain, nchamberlain@atsu.edu
Revised 1/15/10
©2010 Neal R. Chamberlain, Ph.D., All rights reserved