UNDERSTANDING INTERSTITIAL CYSTITIS (IC) & BLADDER PAIN: WHO IS MOST AT RISK?
There has been controversy in the medical literature regarding the definition of interstitial cystitis and use of the term. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the U.S. National Institutes of Health (NIH) established a set of diagnostic criteria for inclusion in research studies relating to interstitial cystitis and its causes that were used for research purposes until 2002. However, the NIDDK criteria were felt to be overly restrictive for diagnostic use, and in 2002, new criteria were proposed for the diagnosis of painful bladder disorders, including the condition referred to as painful bladder syndrome (PBS. These criteria felt that the term PBS was preferable and that the term IC should be restricted to use in those patients having typical findings observed upon cystoscopy and biopsy of the bladder tissues.
ICS criteria state:
- Painful bladder syndrome is the complaint of suprapubic pain related to bladder filling, accompanied by other symptoms such as increased daytime and night-time frequency, in the absence of proven urinary infection or other obvious pathology. The ICS believes this to be a preferable term to “interstitial cystitis.” Interstitial cystitis is a specific diagnosis and requires confirmation by typical clinical cystoscopic and possibly histological features.
In 2006, another set of diagnostic criteria were proposed by the European Society for the Study of IC/BPS, suggesting the use of the term bladder pain syndrome (BPS):
- A diagnosis of bladder pain syndrome (BPS) is made of the basis of the symptom of chronic pain related to the urinary bladder accompanied by at least one other urinary symptom such as daytime and nighttime frequency, AND exclusion of confusable diseases as the cause of the symptoms, AND cystoscopy with hydrodistension and biopsy if indicated (to document the type of BPS/IC).
Until agreement is reached about terminology and definition of the condition, it will be difficult to determine the true prevalence of PBS/IC. Estimates of the number of affected people vary widely and are dependent upon the criteria used for diagnosis.
Despite the lack of agreement about the diagnosis of PBS/IC, studies agree that the majority of those affected are women. While individuals of any age can be affected, including children, the average age of onset is around 40. PBS/IC has not been considered to be a hereditary disorder, but multiple cases have occurred among some families, prompting ongoing investigation of the possible role of hereditary factors in the development of PBS/IC.
Some associations with other medical conditions are seen with PBS/IC. Women with PBS/IC are more likely to have had frequent urinary tract infections and to have had previous gynecologic surgery than women without PBS/IC. Certain chronic illnesses have been described as occurring more frequently in people with PBS/IC than in the general population. Examples of these associated conditions are inflammatory bowel disease, systemic lupus erythematous, irritable bowel syndrome (IBS), vulvodynia (chronic discomfort in the vulvar area), allergies, endometriosis, and fibromyalgia. While each of these conditions has been described in at least some studies to be more common in people with PBS/IC than in the general population, there is no evidence that any of these conditions is the cause of PBS/IC.
Observations from cystoscopy (visual examination of the inside of the bladder via a probe) studies have found that two patterns exist for IC, ulcerative and nonulcerative, depending upon the presence or absence of ulcerations in the bladder lining. Star-shaped ulcerations in the bladder wall are known as Hunner’s ulcers. These are found in less than 10% of cases in the U.S.
Over time, interstitial cystitis can cause physical damage to the bladder wall. Scarring and stiffening of the bladder wall may occur as a result of the chronic inflammation, leading to a decrease in bladder capacity. Glomerulations (areas of pinpoint bleeding) and petechial hemorrhage may be seen on the bladder wall.