More Information on Interstitial Cystitis
Frederick R. Jelovsek MD
The many causes of pelvic pain make it a difficult condition to assign a diagnosis to. Some of the causes, such as interstitial cystitis (IC), are even more difficult to diagnose. The average patient may go many years with symptoms before the diagnosis is made. For that reason it is important to recognize the symptoms of IC.
Interstitial cystitis is characterized by urinary frequency, urgency and pain. The pain can vary from a mild burning or discomfort, to an excruciating pain in the bladder, lower abdomen, perineum, pelvis, vagina, low back pain and thighs according to Sant GR: Interstitial cystitis-- a urogynecologic perspective. Contemporary Ob/Gyn 1998;43(6):119-130. It can include pain with intercourse and is often indistinguishable from other causes of pelvic pain.
The pain can flare-up or go into remission. It usually gets worse around the time of menses. Sexual intercourse makes the pain worse. Patients may void 8 times or more at night and sleep loss may lead to depression. If a woman is voiding more than 8 times during the day or 4 times or more during the night, IC should be considered especially if there is pain or urgency present.
Because the symptoms may be similar to an acute or chronic bacterial infection, patients have often had multiple treatments with antibiotics when in fact the urine culture does not show infection at all. Interstitial cystitis is characterized by an inflammatory response in the bladder wall but bacterial cultures are negative. Antibiotics do not help the pain and urinary frequency. End stage interstitial cystitis (IC) often results in ulcers in the bladder wall that can be seen when a scope (cystoscopy) is used to view the inside of the bladder. The gold standard in diagnosis of IC used to be by cystoscopy in which either ulcers are seen or petechial hemorrhages. Biopsy of the bladder mucosa may not be needed if the appearance is typical. Now. however, the concept of IC is changing.
The skin lining the bladder wall is usually waterproof. In other words the waste products and salts in urine never touch the nerve endings and blood vessels in the layer under the bladder skin (epithelium). Ulcers allow direct contact to this layer and produce pain and often urinary frequency. It used to be thought you did not get bladder pain until there was an ulcer present. Now it is felt that in early disease there may be small holes, leaking in the bladder skin, that allow urine salts to get to the nerve endings and cause pain for years before there are actual ulcers. A test has been developed to see if this leaky epithelium is present. It is called a potassium sensitivity test.
In this test, a mild potassium salt solution is instilled into the bladder by a catheter. If it produces a severe pain compared to instilling just sterile water, then the test is considered positive. Patients who have a positive test often respond (about 60% of the time (1)) to a medicine used to treat interstitial cystitis called pentosan polysulfate (Elmiron(R)). This is significant because up until now, we have not had any good medicines that permanently treat pelvic pain.
With this concept in mind, i.e., that maybe many instances of chronic pelvic pain really represent an early bladder skin dysfunction (IC), investigators set out to test if women with chronic pelvic pain who were not diagnosed as having chronic bladder problems, might have positive potassium (K+Cl) sensitivity tests. They found that in 244 women with pelvic pain, 81% had a positive potassium sensitivity test. None of the 47 control patients had a positive test (2). This would indicate that possibly these women may have an early interstitial cystitis and may benefit from therapy for it.
Other conditions such as irritable bowel syndrome, spastic colon, abdominal cramping, hysterectomy, rheumatoid arthritis, fibromyalgia, hay fever, asthma and food allergies are often associated with interstitial cystitis. These multiple conditions make the diagnosis even more difficult.