As the name implies, prostatitis is the inflammation of the prostate gland.
It is an inflammatory process where the prostate gland increases the number of inflammatory cells. Still, it is not always due to infection of the prostate.
Infectious agents and non-infectious causes are behind this inflammation. A bacterial infection causes acute prostatitis. Non-infectious causes are more common and lead to chronic prostatitis.
The main difference is that acute prostatitis usually has more severe symptoms. Conversely, some cases of chronic prostatitis may be hidden and difficult to detect.
Chronic prostatitis is prolonged over a longer course. But acute prostatitis leads patients into an emergency room. It often needs to be resolved as soon as possible. Still, some cases of acute prostatitis may progress to chronic prostatitis in 5-10% of patients (1, 2).
Thus, acute prostatitis deserves special consideration for anyone interested in men’s health. What should we know about this ailment?
What is Acute Prostatitis?
Acute prostatitis is a sudden inflammation of the prostate gland. Infectious agents are often the cause. In acute prostatitis, patients start experiencing symptoms over a short course.
In some cases, it is associated with urinary tract infections. In other cases, they are sexually transmitted diseases. But there are other causes to rule out (1).
After benign prostatic hyperplasia, prostatitis is one of the most common problems in men. Chronic prostatitis is the most prevalent. Acute prostatitis is not as common but causes more symptoms. It is also more likely to be detected when it appears. Still, the prognosis is excellent, and most patients do not have any sequelae (2).
Symptoms of Acute Prostatitis
What differentiates acute and chronic prostatitis is the severity of the symptoms, and how sudden they are. The most common symptoms of prostatitis are as follows:
- Fever: Acute prostatitis is an inflammatory condition that triggers the release of inflammatory cytokines. Thus, one of the most common findings is fever, which was present in 92% of patients in a cohort study (1, 3).
- Painful urination: Pain symptoms are prevalent in acute prostatitis. Dysuria is very common and described as a burning sensation when urinating. It appears because there is inflammation of the adjacent urethra. Irritation becomes worse in cases of urinary infection and sexually transmitted diseases (4).
- Tenderness in the perineum: Another pain symptom is tenderness in the pelvic floor and the rectum. There may be intense pain when the urologist performs a rectal examination (5).
- Increased frequency of urination: Another urinary symptom the majority of patients share is an increased frequency of urination. The urgency to urinate is also prevalent (4).
- Failure to start urinating or weak urine flow: Acute prostatitis may cause prostate enlargement and edema of the prostate. These problems compromise the urinary stream. Some patients may even have acute urinary retention. They need an emergency surgical draining of the urine with a suprapubic catheter. Micturition problems are found in up to 96% of patients, and around 7% will have urinary retention (3).
- Painful ejaculation: The prostate is important for ejaculation volume. Thus, it is possible to have painful ejaculations or blood in the semen. Yet, this is more prevalent in cases of chronic prostatitis (5).
- Pelvic pain: Patients left untreated may develop a pelvic abscess. Their pain will no longer be restricted to the urinary tract and perineal area. Additionally, around 10% of patients with acute prostatitis develop chronic pelvic pain syndrome. They usually report suprapubic pain or pain in the pelvic area (2).
What Causes Acute Prostatitis?
As we mentioned, the causes of chronic prostatitis are often non-infectious. But the most common cause of acute prostatitis is contamination and colonization by infectious agents.
The most prevalent microbes in acute prostatitis cause urinary tract infections, too. They are Escherichia coli (the most common pathogen), Proteus mirabilis, Pseudomonas aeruginosa, and species of Enterobacter and Klebsiella (6).
In the majority of cases (80%), prostate infections involve one single organism. Other species that cause acute prostatitis include enterococci and staphylococcus aureus. The latter is more commonly acquired in hospitalized patients. It is also associated with a higher risk of prostatic abscesses (5, 7).
But the urine contained in the urinary bladder is sterile. Thus, the question remains: how does E. coli or any other invader microbe end up in the prostate? There are at least 4 mechanisms that explain this migration:
- Urinary reflux to intraprostatic tissues: It is the most commonly accepted mechanism. Infected urine refluxes to intraprostatic tissues instead of being completely eliminated. Bacteria in the urine enter the prostatic duct in the peripheral zone of the prostate. Then, they go ahead and colonize the area (8).
- Ascending infection of the urethra: This one is useful to explain how urethritis and sexually transmitted diseases spread to the prostate. The urethra and the prostate share a very close connection. Thus, microbes in the urethra spread upwards. In time, they reach the prostatic section of the urethra. Once there, they spread to the prostatic tissue. That is how these pathogens invade and cause inflammation in the gland (9).
- Spread of bacteria from the rectum: The prostate is in close continuity with the rectum, too. This is useful in a rectal examination because it is how urologists feel the prostate. But according to this mechanism, bacteria from the rectum migrate to the prostate. They do so either directly or by spread through the lymphatic vessels. This mechanism has been thoroughly described for metastatic prostate cancer. It is considered but often questioned in the field of acute prostatitis (10).
- Spread of bacteria from the blood: Besides a lymphomatous spread of the bacteria, it is also possible to have a hematogenous spread. In other words, bacteria can travel in the blood and reach the prostate. This is equally unlikely than the previous mechanism, but it is always a possibility. It is especially considered in immunocompromised patients. Thus, it is often mentioned, though usually disregarded in the clinical practice (10).
- Direct inoculation in prostatic biopsy: Another important source of infection is by direct inoculation. This often happens in patients who are undergoing prostate biopsy. It is a possibility, even when it’s being guided by transrectal ultrasound. According to recent literature, resistant bacteria are becoming more prevalent. This leads to a higher incidence of acute bacterial prostatitis as a side effect of transrectal prostate biopsy (5).
Acute bacterial prostatitis is not as common as chronic prostatitis. Yet, certain risk factors will increase the chance of having this condition. They are as follows (11, 12):
- Having intraprostatic ductal reflux: We have described how this mechanism is one of the most widely accepted as a cause of acute prostatitis. Patients with intraprostatic ductal reflux have a higher risk or acute bacterial prostatitis. It is usually due to a neurophysiologic or anatomic problem. One way to know if you have this problem is by performing an ultrasound. The presence of prostatic calculi is often indicative of intraprostatic ductal reflux. This is why they are prevalent in patients with signs and symptoms of chronic prostatitis.
- Congenital abnormalities of the urinary tract: In cases of pediatric prostatitis, they are a very likely risk factor. Congenital anomalies of the urinary tract increase the incidence of urinary infections and acute prostatitis.
- Recurrent urinary tract infections: Urinary tract infections in men is a complicated infection until proven contrary. They are not as common in men as they are in women. Thus, when they appear, they are usually accompanied by something else. One of the most common risk factors of prostatitis is urinary tract infections.
- Unprotected anal sex: Sexually-transmitted diseases, such as chlamydia trachomatis, are very likely to cause urethritis and lead to acute prostatitis. This follows the mechanism described above as “ascending infection from the urethra.” Common pathogens include E. coli. This bacterium is abundant throughout the gastrointestinal system, including the anal region.
- Sexual abuse: It is a risk factor to consider, especially in cases of pediatric prostatitis.
- Patients with redundant foreskin and phimosis: It is a risk factor because it facilitates the growth of bacteria in the urethra. Thus, it increases the risk of various infections of the lower urinary tract.
- Abnormal prostatic fluid: Prostatic fluid is essential to make sperm thicker and more abundant. When there’s not enough prostatic fluid, it may be due to prostatic stones. They cause a stagnant fluid inside the prostate. This situation creates a perfect culture for prostatic infections.
- Acute epididymitis: Epididymitis is an infection of the epididymis. This is a structure that connects the testis and the urethra. The mechanism of infection in epididymitis is similar to that of prostatitis. Thus, both epididymitis and prostatitis are often found in the same patient. They are commonly associated with sexually transmitted diseases.
- Certain blood groups: According to a study, having certain blood groups may predispose to prostatitis. Certain blood groups appear to favor the attachment of E. coli in the prostate. Besides the widely known ABH classification of the blood, there is a P blood group. It is based on the presence of antigens named P, P1, and Pk. People with a P blood group, regardless of the variant, have a higher susceptibility to acute bacterial prostatitis.
- Transurethral surgery or prostate biopsy: All surgical procedures that touch the prostate tissue are risk factors. They may directly cause acute bacterial prostatitis. That includes biopsy and transurethral surgery.
- Indwelling catheter: Patients who are maintained for a very long time with a Foley catheter or condom catheter are more likely to have acute prostatitis. It is the same mechanism that predisposes these patients to urinary infections.
Diagnosis of prostatitis usually require three different steps (5):
- Getting information from the patient: Symptoms of acute prostatitis are more severe. Yet, they are easier to identify than chronic prostatitis. So, listening to the patient is very important in the process of diagnosis. If you’re suspecting acute prostatitis, describe what you feel to your urologist. Try to remember everything or make notes if necessary.
- Performing a physical exam: In the majority of cases, listening to the symptoms of the patient and performing a quick review is enough to suspect acute prostatitis. Your doctor may need to assess pain in the pelvic area and the perineum. A rectal examination might be too painful, and it is not always necessary. Prostate massage is contraindicated because it can lead to the dissemination of the pathogen.
- Lab tests: After the initial suspicions, your urologist might need to take a complete blood count, urinalysis, and urine cultures. In some cases, you might need a blood culture. It is usually performed if your doctor thinks there’s a systemic infection.
- In some cases, you will need an emergency assessment: For example, if you have suprapubic tenderness, a mass in your pelvic area, and difficulty to urinate. In these cases, urinary retention is a possibility. So, you will need an ultrasound scan of the urinary bladder.
- An ultrasound will be useful if your doctor suspects a prostatic abscess, too: In these cases, you might need transrectal ultrasonography. Your doctor might also need to treat your prostatic abscess with surgical drainage (5).
Diagnosis and treatment of acute bacterial prostatitis are based on the detection of the pathogen and whether or not there’s a systemic prostate infection.
In mild cases with no systemic infection, oral therapy with antibiotics is enough. Fluoroquinolones are useful for gram-negative bacteria and some gram-positive as well. It accumulates in the prostate in higher concentrations than beta-lactams.
The same antibiotics are the first choice in hospitalized patients with a severe or systemic infection. It is usually combined with an aminoglycoside and penicillin. Treatment depends on antibiotic resistance, and you can follow with oral antibiotics when fever and urinary retention improve (5).
Acute prostatitis is not as common as chronic prostatitis. Yet, it causes more intense symptoms and emergencies.
Mechanisms of the disease include urinary reflux and ascending spread of pathogens in the urinary tract.
Prostate biopsies and other prostatic surgical procedures may be another cause. The causative bacteria is usually E. coli, but it can be from the Enterococcus species and others. It is associated with urinary infections or sexually transmitted diseases.
Mild cases are solved by using oral antibiotics. Severe cases may require intravenous antibiotics and extra treatment measures to stabilize the patient. Prognosis is very good because complications are rare.