Epidemiology

In the United States, 3-6% of women and 2-4% of men have interstitial cystitis. Among women, the average age at onset is the early forties, but the range is from childhood through the early sixties.

Etiology

The etiology of interstitial cystitis remains unknown.

• Theoretical possibilities include chronic bladder infection, inflammatory factors such as mast cells, autoimmunity, increased permeability of the bladder mucosa, and unusual pain sensitivity.
• However, few data support any of these factors as an inciting cause.

Clinical Manifestations

The cardinal symptoms of pain, urinary urgency and frequency, and nocturia occur in no consistent order. Symptoms can begin acutely or gradually. Pain, which is often present at two or more sites, can affect the suprapubic area (80% of pts), the urethra, the vulva, and non-urogenital areas.

• Unlike pelvic pain arising from other sources, pain caused by interstitial cystitis is exacerbated by bladder filling and relieved by bladder emptying.
• Of pts with interstitial cystitis, 85% void >10 times per day; some do so as often as 60 times per day.
• Many pts with interstitial cystitis have comorbid functional somatic syndromes (e.g., fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome).

Diagnosis

The diagnosis is based on the presence of appropriate symptoms and the exclusion of diseases with a similar presentation (e.g., diseases that manifest with pelvic pain and/or urinary symptoms; functional somatic syndromes with urinary symptoms)

• Physical examination and laboratory findings are insensitive and/or nonspecific.
• Cystoscopy may reveal an ulcer (≤10% of pts) or petechial hemorrhages after bladder distension, but neither of these findings is specific.