Prostatitis refers to a disparate group of disorders that manifests with a combination of predominantly irritative or obstructive urinary symptoms and perineal pain. Some cases result from bacterial infection of the prostate gland and others, which are more common, from a poorly understood combination of noninfectious inflammatory factors, spasm of the muscles of the urogenital diaphragm, or both. Diagnosis is clinical, along with microscopic examination and culture of urine samples obtained before and after prostate massage. Treatment is with an antibiotic if the cause is bacterial. Nonbacterial causes are treated with warm sitz baths, muscle relaxants, and anti-inflammatory drugs or anxiolytics.
Prostatitis can be bacterial or, more commonly, nonbacterial. However, differentiating bacterial and nonbacterial causes can be difficult, particularly in chronic prostatitis.
Bacterial prostatitis can be acute or chronic and is usually caused by typical urinary pathogens (eg, Klebsiella, Proteus, Escherichia coli) and possibly by Chlamydia. How these pathogens enter and infect the prostate is unknown. Chronic infections may be caused by sequestered bacteria that antibiotics have not eradicated.
Nonbacterial prostatitis can be inflammatory or noninflammatory. The mechanism is unknown but may involve incomplete relaxation of the urinary sphincter and dyssynergic voiding. The resultant elevated urinary pressure may cause urine reflux into the prostate (triggering an inflammatory response) or increased pelvic autonomic activity leading to chronic pain (see Pain: Chronic Pain) without inflammation.
Prostatitis is classified into 4 categories (see Table 2: Benign Prostate Disease: NIH Consensus Classification System for Prostatitis). These categories are differentiated by clinical findings and by the presence or absence of signs of infection and inflammation in 2 urine samples. The first sample is a midstream collection. Then digital prostate massage is done, and patients void immediately; the first 10 mL of urine constitutes the 2nd sample. Infection is defined by bacterial growth in urine culture; inflammation is defined by the presence of WBCs in urine.
Symptoms and Signs
Symptoms vary by category but typically involve some degree of urinary irritation or obstruction and pain. Irritation is manifested by frequency and urgency, obstruction, a sensation of incomplete bladder emptying, a need to void again shortly after urinating, or nocturia. Pain is typically in the perineum but may be perceived at the tip of the penis, lower back, or testes. Some patients report painful ejaculation.
Acute bacterial prostatitis often causes such systemic symptoms as fever, chills, malaise, and myalgias. The prostate is exquisitely tender and focally or diffusely swollen, boggy, indurated, or a combination. A generalized sepsis syndrome may result, characterized by tachycardia, tachypnea, and sometimes hypotension.
Chronic bacterial prostatitis manifests with recurrent episodes of infection with or without complete resolution between bouts. Symptoms and signs tend to be milder than in acute prostatitis.
Chronic prostatitis/chronic pelvic pain syndrome typically has pain as the predominant complaint, often including pain with ejaculation. The discomfort can be significant and often markedly interferes with quality of life. Symptoms of urinary irritation or obstruction also may be present. On examination, the prostate may be tender but usually is not boggy or swollen.
Asymptomatic inflammatory prostatitis causes no symptoms and is discovered incidentally during evaluation for other prostate diseases when WBCs are present in the urine.
Diagnosis of type I, II, or III prostatitis is suspected clinically. Similar symptoms can result from urethritis, perirectal abscess, or UTI. Examination is helpful diagnostically only in acute bacterial prostatitis.
Febrile patients with typical symptoms and signs of acute bacterial prostatitis usually have WBCs and bacteria in a midstream urine sample. Prostate massage to obtain a postmassage urine sample is thought to be unnecessary and possibly dangerous in these patients (although danger remains unproved) because bacteremia can be induced. For the same reason, rectal examination should be done gently. Blood cultures should be obtained in patients who have fever and severe weakness, confusion, disorientation, hypotension, or cool extremities. For afebrile patients, urine samples before and after massage are adequate for diagnosis.
For patients with acute or chronic bacterial prostatitis who do not respond favorably to antibiotics, transrectal ultrasonography and sometimes cystoscopy may be necessary to rule out prostatic abscess or destruction and inflammation of the seminal vesicles.
For patients with types II, III, and IV (nonacute prostatitis) disease, additional tests that can be considered are cystoscopy and urine cytology (if hematuria is also present) and urodynamic measurements (if there is suspicion of neurologic abnormalities or detrusor-sphincter dyssynergia).
Acute bacterial prostatitis
Nontoxic patients can be treated at home with antibiotics, bed rest, analgesics, stool softeners, and hydration. Therapy with a fluoroquinolone (eg, ciprofloxacin 500 mg po bid or ofloxacin 300 mg po bid) is usually effective and can be given until culture and sensitivity results are known. If the clinical response is satisfactory, treatment is continued for about 30 days to prevent chronic bacterial prostatitis.
If sepsis is suspected, the patient is hospitalized and given broad-spectrum antibiotics IV (eg, ampicillin plus gentamicin). Antibiotics are started after the appropriate cultures are taken and continued until the bacterial sensitivity is known. If the clinical response is adequate, IV therapy is continued until the patient is afebrile for 24 to 48 h, followed by oral therapy usually for 4 wk.
Adjunctive therapies include NSAIDs and potentially α-blockers (if bladder emptying is poor) and supportive measures such as sitz baths. Rarely, prostate abscess develops, requiring surgical drainage.
Chronic bacterial prostatitis
Chronic bacterial prostatitis is treated with oral antibiotics such as fluoroquinolones for at least 6 wk. Therapy is guided by culture results; empiric antibiotic treatment for patients with equivocal or negative culture results has a low success rate. Other treatments include anti-inflammatory drugs, muscle relaxants (eg, cyclobenzaprine to possibly relieve spasm of the pelvic muscles), α-adrenergic blockers, and other symptomatic measures, such as sitz baths.
Chronic prostatitis/chronic pelvic pain syndrome
Treatment is difficult and often unrewarding. In addition to considering any and all of the above treatments, anxiolytics (eg, SSRIs, benzodiazepines), sacral nerve stimulation, biofeedback, prostatic massage, and minimally invasive prostatic procedures (such as microwave thermotherapy) have been attempted with varying results.
Asymptomatic inflammatory prostatitis
Asymptomatic prostatitis requires no treatment.
Prostate abscesses are focal purulent collections that develop as complications of acute bacterial prostatitis.
The usual infecting organisms are aerobic gram-negative bacilli or, less frequently, Staphylococcus aureus. Urinary frequency, dysuria, and urinary retention are common. Perineal pain, evidence of acute epididymitis, hematuria, and a purulent urethral discharge are less common. Fever is sometimes present. Rectal examination may disclose prostate tenderness and fluctuance, but prostate enlargement is often the only abnormality, and sometimes the gland feels normal.
Abscess is suspected in patients with continued or recurrent UTIs despite antimicrobial therapy and persistent perineal pain. Such patients should undergo prostate ultrasonography and possibly cystoscopy. Many abscesses, however, are discovered unexpectedly during prostate surgery or endoscopy; bulging of a lateral lobe into the prostatic urethra or rupture during instrumentation reveals the abscess. Although pyuria and bacteriuria are common, urine may be normal. Blood cultures are positive in some patients.
Treatment involves appropriate antibiotics plus drainage by transurethral evacuation or transperineal aspiration and drainage. Pending culture results, empiric antibiotic therapy is begun with a fluoroquinolone (eg, ciprofloxacin).
Last full review/revision January 2013 by Gerald L. Andriole, MD