OBJECTIVETo investigate the differential diagnosis of type III prostatitis and interstitial cystitis so as to improve the efficiency of diagnosis and treatment of the two diseases.

METHODSBased on the clinical data of 4 cases of type III prostatitis and 3 cases of interstitial cystitis, we analyzed the characteristics of the two diseases in such aspects as clinical symptomatology, urodynamics, prostatic fluid microscopy, microbiology and treatment.

RESULTSThe common clinical characteristics of type III prostatitis and interstitial cystitis were indisposition or pain in the subabdomen and/or pelvic floor, but their differences were quite obvious. In interstitial cystitis, longer urine accumulation could cause worse pain in the subabdomen, which could be relieved after micturation, and the bladder capacity was obviously decreased, but with normal prostatic fluid and negative result of microbial culture. It responded to behavior therapy, resiniferatoxin, sodium hyaluronate and water dilation of the bladder under anaesthesia. While type III prostatitis, with white blood cells > 10/HP or < or = 10/HP in the prostatic fluid and negative result of microbial culture, did not respond to the above therapeutic methods that were effective for interstitial cystitis.

CONCLUSIONType III prostatitis and interstitial cystitis, although clinically confusable, can be definitely differentiated from each other according to their characteristic causes and locations.