Interstitial cystitis. Etiology, diagnosis, and treatment.

OBJECTIVE: To review current knowledge about the epidemiology, etiology, diagnosis, and treatment of interstitial cystitis, with special emphasis on management of this condition by family physicians. QUALITY OF EVIDENCE: Articles were identified through MEDLINE and review of abstracts presented at Urology and Interstitial Cystitis meetings during the last decade. Recent reviews were further searched for additional studies and trials. Data were summarized from large epidemiologic studies. Etiologic theories were extracted from current concepts and reviews of scientific studies. Diagnostic criteria described in this review are based on clinical interpretation of National Institutes of Health (NIH) research guidelines, interpretation of data from the NIH Interstitial Cystitis Cohort Study, and recent evidence on use of the potassium sensitivity test. Treatment suggestions are based on six randomized placebo-controlled clinical treatment trials and best available clinical data. MAIN MESSAGE: Interstitial cystitis affects about 0.01% to 0.5% of women. Its etiology is unknown, but might involve microbiologic, immunologic, mucosal, neurogenic, and other yet undefined agents. The diagnosis of interstitial cystitis is a diagnosis of exclusion. It is impossible to provide a purely evidence-based treatment strategy, but review of available evidence suggests that conservative supportive therapy (including diet modification); oral treatment with pentosan polysulfate, amitriptyline, or hydroxyzine; and intravesical treatments with heparinlike medications, dimethyl sulfoxide, or BCG vaccine could benefit some patients. CONCLUSION: Family physicians should have an understanding of interstitial cystitis and be able to make a diagnosis and formulate an evidence-based treatment strategy for their patients.