Interstitial cystitis greatly underdiagnosed. (Expert Opinion).

BALTIMORE -- Physicians should become more alert to the signs and symptoms of interstitial cystitis, a condition that is significantly underdiagnosed, Dr. Marcella L. Roenneburg said at a symposium on women's health sponsored by Mercy Medical Center.

For patients who have urinary urgency frequency dyspareunia, and pain and discomfort in the pelvic, perineal, and bladder areas but have negative urine cultures, "we need to suspect interstitial cystitis far more often than we currently are doing," she said.

Descriptions of interstitial cystitis (IC) as rare and difficult to diagnose and treat are myths, she said. Although about 100,000 people in this country are currently diagnosed with IC, there may be 1 million or more with the disorder, said Dr. Roenneburg, who is a urogynecologist at the Greater Baltimore Medical Center.

Most people with IC are between ages 30 and 70 years (mean age is 42-46), and the female-to-male ratio is about 9:1. Patients often have symptoms for 4-7 years before they seek medical help.

The cause is unclear. Some investigators believe that an infection may release some toxin or chemical that triggers damage to the bladder; others have postulated that there is an allergic cause. Other possibilities are a neurogenic etiology or epithelial dysfunction, but the cause is "probably multifactorial," Dr. Roenneburg said during the meeting.

Part of the pathogenesis of IC involves damage to the epithelial layer of the bladder, resulting from some type of insult to the bladder, so potassium leaks into the interstitium, continuing the vicious cycle of bladder injury.

Physicians find IC difficult to diagnose, probably because it's a diagnosis of exclusion and there is no specific blood or urine test for confirmation. Dr. Roenneburg highlighted certain clues in a patient's history and physical and several lab tests that can lead to a presumptive diagnosis. "You'll find that many of these patients will respond to therapy."