Prostatitis overview

# Overview
Prostatitis is an inflammation of the prostate gland. Prostatitis has been classified by International Prostatitis Collaboration Network, into 5 subtypes. This classification is on the basis of timing of the symptoms and the presence of bacterial pathogens and other markers of infection and inflammation. The categories include acute bacterial prostatitis, chronic bacterial prostatitis, inflammatory chronic prostatitis/chronic pelvic pain syndrome, non-inflammatory chronic prostatitis/chronic pelvic pain syndrome, and asymptomatic inflammatory prostatitis. By the help of microscopic histopathological studies, neutrophils or lymphocytes can be seen inside the glands, between the cells of epithelium or inside the stromal component. The most common bacteria causing prostatitis are aerobic gram-negative bacilli, Escherichia coli is responsible for 50-80% incidents of bacterial prostatitis. Though a single definitive cause has not been established, different theories exist about chronic prostatitis/chronic pelvic pain syndrome pathogenesis including chemical damage owing to reflux or autoimmune process. Prostatitis must be differentiated from various causes of dysuria including pyelonephritis, cystitis, urethritis, benign prostatic hyperplasia, prostatic abscess, bladder cancer, urinary tract stones, and a foreign body within the urinary tract. Recurrent urinary tract infections, benign prostatic hyperplasia, urethral strictures, bladder neck hypertrophy, prostatic carcinoma, and catheterization are risk factors for prostatitis. Acute prostatitis usually results in complete recovery without sequelae. If left untreated, patients with acute bacterial prostatitis may progress to develop chronic prostatitis, epididymitis, prostatic abscess, septicemia, urosepsis, urinary retention and metastasis of infection to spinal cord or sacroiliac joint. Patients with untreated chronic prostatitis may develop chronic pelvic pain, sexual dysfunction, infertility and recurrent urinary tract infections. Frequency, urgency, burning during urination, nocturia, urinary retention and pain in the genital area, groin, lower abdomen, or lower back may be the presenting features. Other features include fever, nausea, and vomiting in acute infection. Laboratory findings show an increase in the number of leukocytes on CBC, bacteria on urine culture, elevated C-reactive protein, and transiently elevated PSA (prostate specific antigen) levels in case of bacterial prostatitis. While in chronic bacterial prostatitis negative pre-massage urine culture results, more than 10 to 20 leukocytes per high-power field in both the pre and the post massage urine specimen, bacteriuria in the postmassage urine specimen, and lower leukocyte and bacterial counts in voided bladder urine specimens as compared to bacterial count in post-prostatic massage voided urine or expressed prostatic secretions are seen. The absence of bacterial growth on cultures is diagnostic of chronic nonbacterial prostatitis.
Antimicrobial therapy is indicated for acute and chronic prostatitis.

# Historical Perspective
In 350 BC, the anatomical positioning and existence of the prostate gland was explained by Herophilus. Prostatic incitement was recognised as a cause of prostatitis in 1800. In 1978 Drach et al. gave the basis of the current classification of prostatitis.

# Classification
Prostatitis has been classified by International Prostatitis Collaboration Network, into 5 subtypes. This classification is done on the basis of timing of the symptoms and the presence of bacterial pathogens and other markets of infection and inflammation. The categories include:
- Acute bacterial prostatitis
- Chronic bacterial prostatitis
- Inflammatory chronic prostatitis/chronic pelvic pain syndrome
- Non-inflammatory chronic prostatitis/chronic pelvic pain syndrome
- Asymptomatic inflammatory prostatitis.

# Pathophysiology
The pathogenesis of prostatitis is not completely understood. An infection ascending from the urethra, chemical damage caused by the reflux of urine through the ejaculatory ducts and prostatic ducts and autoimmune involvement are a few possible theories related to the pathogenesis of various types of prostatitis. Chronic prostatitis/chronic pelvic pain syndrome is thought to be caused by an abnormality in the hypothalamic-pituitary-adrenal axis and hormonal derangements involving the adrenocortical hormone. These changes can stem from variable response to stress, neurogenic inflammation, and myofascial pain syndrome. On microscopic examination, neutrophils or lymphocytes can be seen inside the prostatic gland, among the cells of the epithelium or inside the stromal component of the gland.

# Causes
The most common bacteria causing prostatitis are aerobic gram-negative bacilli, Escherichia coli is responsible for 50-80% incidents of bacterial prostatitis.Though a single definitive cause has not been established, different theories exist about chronic prostatitis/chronic pelvic pain syndrome pathogenesis including chemical damage owing to reflux or autoimmune process.

# Differential Diagnosis
Prostatitis must be differentiated from various entities on the basis of dysuria that include cystitis, pyelonephritis, benign prostatic hyperplasia, prostatic abscess, bladder cancer, urinary tract stones, and a foreign body within the urinary tract.

# Epidemiology and demographics
In men who are younger than 50 years of age, prostatitis is the most common problem related to the urinary tact. Prostatitis is the 3rd most common urinary diagnosis made in men aged more than 50 years. There are almost 2 million health care visits yearly, associated with prostatitis. Chronic prostatitis is the most commonly seen type of prostatitis.

# Risk Factors
Common risk factors in the development of prostatitis include recurrent urinary tract infections, urethral strictures, hypertrophy of the neck of the bladder, prostatic carcinoma, benign prostatic hyperplasia,use of alcohol, smoking and history of foley catheterization.

# Natural History, Complications, and Prognosis
If left untreated, patients with acute bacterial prostatitis may progress to develop chronic prostatitis, prostatic abscess, septicemia, urosepsis, urinary retention and metastasis of infection to spinal cord or sacroiliac joint. Patients with untreated chronic prostatitis may develop chronic pelvic pain, sexual dysfunction, infertility, severe urinary frequency and urgency, and recurrent urinary tract infections. Complete recovery without sequelae is usual among patients with acute prostatitis. Patients with chronic prostatitis have a gradual recovery and relapse is common.

# Screening
United States preventive task force (USPSTF) has no guidelines till date for the screening of prostatitis in men.

# Diagnosis

## Diagnostic Study of Choice
There is no gold standard for the diagnosis and evaluation of patients presenting with prostatitis. The evaluation of a patient with acute and chronic bacterial prostatitis consists of history and physical examination and urine culture for lower urinary tract localization cultures, respectively. The evaluation of chronic pelvic pain syndrome includes tests which can be broadly divided into mandatory, recommended and optional.

## History and Symptoms
A detailed and thorough history from the patient is necessary. Specific areas of focus when obtaining a history from the patient include previous history of sexually transmitted diseases, any new sexual partners, known urogenital disorders, and recent catheterization or other genitourinary instrumentation. Common symptoms of acute and chronic bacterial prostatitis include urinary frequency, urinary urgency, burning during urination, nocturia, urinary retention and pain in the genital area, groin, lower abdomen, or lower back. Symptoms of acute prostatitis may also include fever, nausea, and vomiting.

## Physical Examination
Patients with chronic prostatitis are usually well-appearing. Patients with acute prostatitis may appear ill and have systemic symptoms such as fever, chills, and nausea. In acute prostatitis, palpation of the prostate reveals a tender and enlarged prostate.
In chronic prostatitis, palpation of the prostate reveals a tender and soft (boggy) prostate gland. A prostate massage should never be done in a patient with suspected acute prostatitis, since it may induce sepsis.

## Laboratory Findings
The laboratory tests used in the diagnosis of prostatitis  are CBC, urinalysis, serum PSA (prostate-specific antigen) levels, urine culture, postvoid residual volume levels, 2-glass pre and post-prostatic massage test, Stamey-Meares four-glass test, and a semen analysis. Laboratory findings consistent with the diagnosis of acute prostatitis include increased leukocytes on complete blood picture, bacteria seen on urine culture, elevated C-reactive protein, and transiently elevated PSA (prostate specific antigen) levels. Laboratory findings consistent with the diagnosis of chronic bacterial prostatitis include negative pre-massage urine culture results, more than 10 to 20 leukocytes per high-power field in both the pre and the post massage urine specimen, bacteriuria in the postmassage urine specimen, and lower leukocyte and bacterial counts in voided bladder urine specimens as compared to bacterial count in post-prostatic massage voided urine or expressed prostatic secretions. The absence of bacterial growth on cultures is diagnostic of chronic nonbacterial prostatitis.

## Imaging Findings
CT scan in a patient with prostatitis shows edema of the prostate gland with diffuse enlargement, mostly in the peripheral zone. An abscess may be seen as a rim enhancing hypodensity which can either have  single or multiple loci. Ultrasound can be used to diagnose prostatitis. On ultrasonography, focal hypoechoic area in the periphery of the prostate represents prostatitis. Fluid collection can show abscess formation. Colour doppler ultrasound may also prove to be very effective. MRI can also be used to diagnose prostatitis. Though it is not used commonly, its utilisation when suspecting alternate diagnosis like prostatic carcinoma etc is very important. MRI in case of a patient wit prostatitis depicts diffuse enlargement of the gland.

# Treatment

## Medical Therapy
Antimicrobial therapy is indicated for acute and chronic prostatitis. Patients are generally treated in an outpatient setting unless severe disease (e.g. bacteremia) is suspected. Empirical therapy for both acute and chronic prostatitis includes monotherapy with either ciprofloxacin, levofloxacin, or TMP-SMX for at least 6 weeks. When culture results are obtained, antimicrobial therapy may be narrowed down to cover the causative pathogen more adequately. Addition of alpha blocker may be considered for the symptomatic management of bacterial prostatitis. Inflammatory prostatitis may be treated with NSAIDs, allopurinol, or cernilton.