Current definition and classification

Technically the term means inflammation of the prostate. An inflammation is caused by the reaction of the immune-system of your body against substances deemed foreign by said body. These may be parasites, pollen, dust, bacteria, viruses and others.
(To simplify: if the foreign body is external and “non-living” the reaction is called an allergy otherwise it is an infection. An auto-immune reaction is directed against your own bodily tissues. The immune reactions of your body are commonly classified in four hypersensitivity types.)

The current classification is according to the American National Institute of Health (NIH) consensus presented in 1995 and published for clinical use in 1999. It is the currently most common.

Bacterial prostatitis—NIH-I and NIH-II
Obviously pathogenic micro-organisms can only be identified as the promoters and cause of inflammation in very few cases, which also are pretty easily treated with antibiotics. This condition is called acute bacterial prostatitis (NIH-I) if onset is sudden and causing obvious illness. Prostate is also abnormal in NIH-I. If infection recurs – usually with milder symptoms than the acute form – it is called chronic bacterial prostatitis (NIH-II). This is more common in older (>50y) men. Only 5-10% of the prostatitis diagnosed patients are thought to suffer from bacterial prostatitis. Curiously only about 5% of IC patients also show “gross inflammatory disease” . (1)

Chronic prostatitis / chronic pelvic pain syndrome—NIH-IIIa and NIH-IIIb
If no obviously pathogenic or known micro-organism can be identified the condition is called chronic prostatitis/chronic pelvic pain syndrome (NIH-III, CP/CPPS; idiopathic or abacterial prostatitis). If markers of inflammation (white blood cells above a certain cut-off in semen, VB3-urine, first void after prostatic massage, and EPS) are found the condition is further sub-categorized as inflammatory CP/CPPS (NIH-IIIa), else non-inflammatory CP/CPPS (NIH-IIIb). The latter condition is also known as “pelvic myoneuropathy”, ”pelvic myofascial syndrome” or “prostatodynia” or “pelvic floor tension myalgia” depending on assumed cause. A study indicated that NIH-III patients can roughly be divided in 25% type ‘a’ and 75% type ‘b’ (2), while another found that only 33% had an inflamed prostate (with 5% having moderate or severe inflammation)(3) . It should be noted that the official leukocyte count is of questionable use, as correlation with symptoms is low (4) and as up to 20% of healthy controls have higher levels ! (5)

Do note that before the NIH system the term chronic prostatitis commonly encompassed NIH-II, NIH-IIIa and NIH-IIIb.

Asymptomatic inflammatory prostatitis—NIH-IV
Sometimes inflammation of the prostate is discovered incidentally or by biopsy, in patients not expressing any symptoms or concerns common to other prostatitis sufferers. This condition is called asymptomatic inflammatory prostatitis (NIH-IV).

Addendum feb 4
The current classification has hung around since the early forties in one way or another with various renamings of the four categories. It still does not take into account (obviously) the possibility of non-prostate related causes, and is essentially misleading by its focus on leukocytes and infection.


Andra bloggar om CPPS, kroniskt bäckenbottensmärtsyndrom, kronisk abakteriell prostatit, NIHIIIb, NIHIIIa
__________________
(1) Moldwin RM Similarities between IC and male CPPS. Curr Urol Rep 3:313-318
(2) Hosseini A, Ehrèn I, Peter Wiklund P. The use of intraprostatic nitric oxide measurements to differentiate between inflammatory and non-inflammatory abacterial chronic prostatitis.
(3) True LD, Berger RE, Rothman I, Ross SO, Krieger JN. Prostate histopathology and the chronic prostatitis/chronic pelvic pain syndrome: a prospective biopsy study. J Urol. 162(6):2014-2018, 1999.
(4) Schaeffer AJ, Datta NS, Fowler JE et al. Overview summary statement-diagnosis and management of CP/CPPS. Urology 60(6):1-4, 2002
(5) Nickel JC, Alexander RB, Schaeffer AJ et al. Leukocytes and bacteria in men with CP/CPPS compared to asymptomatic controls. J Urol 170(3):818-822, 2003.