[Interstitial cystitis. An important differential diagnosis].

Interstitial cystitis (IC) is a chronic, debilitating inflammatory disease of the urinary bladder, characterized by chronic pelvic pain, urgency/frequency symptoms, and decrease of the functional bladder capacity. Both the etiology and pathogenesis of the condition that predominantly affects women are still not fully understood. Thus, a causal therapeutic approach still does not exist. IC remains a strict diagnosis of exclusion; distinct histopathological findings within the bladder wall are frequently found, although they are not pathognomonic. The diagnostic criteria elaborated by the NIH are helpful in clinical research; their dogmatic utilization will however lead to an underdiagnosis of IC in 60% of the patients. IC-specific symptom questionnaires and validated symptom scales help the physician to assess the therapeutic response during the follow-up of the patients.