Introduction
Prostatitis presents as a pattern of symptoms characterized by pelvic pain, dysuria, urgency, frequency, sensation of incomplete voiding, and, in some cases, fever. Prostatitis is the most common urologic condition affecting men under 50 years old and is the third most common urologic condition affecting men older than 50 years old. Worldwide the prevalence of prostatitis ranges from 2.2% to 16%. , In North America, the mean prevalence of prostatitis is 6.9%. With myriads of symptomology, prostatitis is often difficult to diagnose and can result in a large number of physician visits. The Urologic Disease in America study estimated the annual physician visit rate to be 1798 per 100,000 population for prostatitis. In the year 2000, the United States spent 84 million dollars solely on diagnosis and management of this condition. Therefore, this condition can pose a tremendous personal and economic burden to individuals and society.
Etiology and Pathogenesis
Prostatitis is traditionally thought to be caused by bacterial infections; however, recent developments suggest the etiology of this condition to be complex and multifactorial. Acute and chronic bacterial prostatitis makes up a small subset of the population affected by this condition. The most common bacterial agents implicated are from the Enterobacteriaceae family, which originate in the gastrointestinal flora. Other infectious agents include Enterococci family, Corynebacterium species, Chlamydia trachomatis, Ureaplasma urealyticum, and Candia species. , There are certain host factors that increase the risks of developing prostatitis by allowing infectious agents to transcend into the prostatic tissue, including dysfunctional voiding syndrome and intraprostatic ductal reflux. ,
Interestingly, approximately 95% of prostatitis cases are noninfectious. Inflammatory nonbacterial prostatitis is thought to be immunologically mediated and caused by unknown antigens or even an autoimmune process. This is supported by numerous studies demonstrating elevated levels of IgA and IgM antibodies (not microorganism specific), cytokines, and complement factors in the prostatic tissue.
In a large number of patients presenting with prostatitis, no infectious source or inflammation can be found. Emerging evidence suggests that these patients have a dissociation between their central nervous system and pelvic floor where they are unable to voluntarily the striated muscles of the pelvis in a coordinated fashion. This may lead to some of the urinary symptoms associated with prostatitis. Studies have also shown that many patients with prostatitis have myofascial trigger points and autonomic nervous system changes in the pelvis that explain the associated pelvic pain. , The pathogenesis of noninfectious noninflammatory prostatitis is continuously evolving; however, current evidence suggests that pelvic floor dysfunction and neural sensitization are some of the major driving factors in this condition. ,
Clinical Features
The National Institute of Health (NIH) classifies prostatitis in four different categories as shown in Table 5.1 . , Category I is acute bacterial prostatitis. , , Category II is chronic bacterial prostatitis where patients have chronic lower urinary tract infection from a prostatic nidus. , , Category III is nonbacterial prostatitis. Category III is further subdivided into category IIIA and IIIB. , , Category IIIA is nonbacterial inflammatory prostatitis as evidenced by the presence of leukocytes in postprostatic massage urine or semen samples. Category IIIB is nonbacterial noninflammatory prostatitis due to a lack of leukocytes in the postprostatic massage. Finally, category IV is asymptomatic inflammatory prostatitis. Patients are classified as having category IV prostatitis by the presence of significant leukocytes (or bacteria or both) in prostate-specific specimens (semen, tissue biopsy) in the absence of typical chronic pelvic pain. , ,
National Institute of Health Classification | Traditional Classification | Description | Clinical Features |
---|---|---|---|
Category I | Acute bacterial prostatitis | Acute infection of the prostate gland | Fever, chills, malaise, nausea/vomiting, dysuria, urgency, frequency, hesitancy and sensation of incomplete emptying, pain in suprapubic region/perineum |
Category II | Chronic bacterial prostatitis | Chronic infection of the prostate gland | Pelvic pain, dysuria, urgency, frequency, hesitancy, and sensation of incomplete emptying |
Category IIIA | Nonbacterial inflammatory prostatitis | Large number of leukocytes in prostatic secretions, postprostatic massage urine or semen | Pain in the perineum, suprapubic region, and penis |
Category IIIB | Nonbacterial noninflammatory prostatitis | Minimal number of leukocytes in prostatic secretions, postprostatic massage urine or semen | Pain in the perineum, suprapubic region, and penis |
Category IV | Asymptomatic | Presence of leukocytes and/or bacterial in prostatic secretions, postprostatic massage urine or semen | Asymptomatic |
Patients with category I prostatitis will present with dysuria, urgency, frequency, hesitancy, and sensation of incomplete emptying. , Patients will also report pain in the suprapubic region and perineum. , Occasionally, patients may have discomfort in their external genitalia. Category I prostatitis manifests with significant systemic symptoms including fever, chills, malaise, nausea, or vomiting. In several cases, the patient may present with florid septicemia. With timely diagnosis and appropriate treatment, most acute bacterial prostatitis resolve; however, 5% of acute bacterial prostatitis may progress to chronic bacterial prostatitis.
The hallmarks of category II prostatitis are recurrent urinary tract infections. , These patients may have multiple acute episodes spaced by asymptomatic periods. , Each of these episodes are characterized by irritative and obstructive urinary symptoms. , Almost all of these patients will have a long history of pelvic pain. Systemic symptoms such as fever, chills, malaise, nausea, and vomiting are uncommon. ,
Category IIIA and IIIB prostatitis have similar clinical symptoms. The predominant feature of category III prostatitis is a pain in the perineum, suprapubic region, and penis. The NIH Chronic Prostatitis Cohort Study is one of the largest population-based studies that characterize category III prostatitis. Based on this study, perineal pain is the most prevalent pain symptom (63%), following by testicular pain (58%), pain in the pubic region (42%), and pain in the penis (32%). One of the most prominent and important symptoms of this condition is pain during or after ejaculation. In addition to pain, patients may or may not have urinary urgency, frequency, hesitancy, or sensation of incomplete voiding. Many patients with category III prostatitis have severely diminished quality of life; and therefore, may have concurrent psychiatric conditions such as depression or maladaptive coping skills.
Category IV prostatitis is a condition that presents without symptoms. These patients are incidentally discovered during the evaluation of benign prostatic hyperplasia, elevated prostate-specific antigen, prostate malignancy, or infertility. Evaluation for these conditions may reveal the presence of bacteria or leukocytes in the postprostate massage urine specimen or inflammatory infiltrate in the prostate biopsy specimen.
Diagnosis
Diagnosis of prostatitis requires a comprehensive history, physical exam, and appropriate laboratory testing. With regards to laboratory testing, the gold standard for evaluation of prostatitis is the Meares–Stamey Test (also known as 4-Glass Test). This diagnostic test involves four glass test tubes. Test tube 1 contains the first 10 mL of urine and represents the urethral specimen. Test tube 2 contains midstream urine and represents urine from the bladder. Test tube 3 contains expressed prostatic specimens after a prostate massage. Test tube 4 contains the first 10 mL of urine after prostate massage and represents a prostatic specimen. All of these specimens undergo cytologic evaluation and culture. Table 5.2 shows the cytologic and culture results from these specimens depending on the etiology of prostatitis.
Classification | Specimen | TT1 | TT2 | EPS | TT3 |
---|---|---|---|---|---|
CAT I | WBC | + | + | + | + |
Culture | + | + | + | + | |
CAT II | WBC | – | +/− | + | + |
Culture | – | +/− | + | + | |
CAT IIIA | WBC | – | – | + | + |
Culture | – | – | – | – | |
CAT IIIB | WBC | – | – | – | – |
Culture | – | – | – | – |
The Meares–Stamey test can be time consuming. Many clinicians use a 2-Glass Test where the urine sample is collected before and after a prostate massage. These urine specimens are used for cytologic evaluation and culture. This technique is fast and cost effective. The 2-Glass Test has 91% sensitivity and specificity compared with the gold standard Meares–Stamey test. Table 5.3 shows the interpretation of a 2-Glass Test.
Classification | Specimen | Pre-M | Post-M |
---|---|---|---|
CAT I | WBC | + | + |
Culture | + | + | |
CAT II | WBC | +/− | + |
Culture | +/− | + | |
CAT IIIA | WBC | – | + |
Culture | – | – | |
CAT IIIB | WBC | – | – |
Culture | – | – |