When to suspect interstitial cystitis

Some studies suggest that bladder glycosaminoglycans—which form a coating on the luminal surface of the bladder that creates an impermeable, protective barrier—may be compromised in patients with IC/BPS,¹³ which makes it possible for noxious molecules in the urine to activate sensory nerve endings and lead to chronic pelvic pain.

Overlapping symptoms, comorbidities are common
Symptoms associated with IC/BPS overlap with those of a number of other conditions, including UTIs, sensory urgency, recurrent cystitis, and overactive bladder (OAB), as well as chronic nonbacterial prostatitis in men.⁴ Comorbidities further complicate the picture.^14,15

IC/BPS patients often have a history of allergies,^14,15 although they may have negative results on radioallergosorbent (RAST) or skin prick tests, and a number of other comorbidities (TABLE 1). Studies have shown a high correlation between IC/BPS and chronic fatigue syndrome, irritable bowel syndrome, vulvodynia, fibromyalgia, endometriosis, and panic disorder.^16-20

TABLE 1
Interstitial cystitis/bladder pain syndrome: Common comorbidities^14-20

Rule out UTIs and overactive bladder

IC/BPS is largely a diagnosis of exclusion: When a patient presents with suprapubic pain, pressure, or discomfort related to bladder filling and increased urinary frequency lasting for several months, other related conditions—most notably, UTI and OAB—must be ruled out. Often, this can be done with urinalysis and culture, a complete medical history, and symptom assessment. But when doubt remains, a trial of antibiotics (for a UTI) or an anticholinergic agent (for OAB) may be appropriate.

A targeted history and symptom assessment
A history of allergic, gastrointestinal, gynecologic, and/or musculoskeletal disease is often significant.⁴ In addition, bladder problems in childhood and adolescence are notable, as they are far more common in women with IC/BPS than in the general population.^21,22

Identify voiding problems. Question the patient not only about how often she voids, but also about the extent to which the frequency is affecting her life. The severity of the persistent need to void is more significant for an IC/BPS diagnosis than the sudden urge to void for fear of leakage, which is typical of OAB.²³

Ask about abuse. Evidence suggests that 50% of women with IC/BPS have been abused, half of them sexually,²⁴ so it is important to include questions about past and present physical, emotional, and sexual abuse in the medical history. Physical or sexual trauma in childhood appears to increase an individual’s lifetime risk for chronic pain syndromes.²⁵

Use these tools to gauge symptoms and severity. Two tools that can aid in diagnosing—or ruling out—IC/BPS are the O’Leary-Sant Symptom and Problem Index, and the Pelvic Pain and Urgency/Frequency (PUF) questionnaire. Both are available at https://www.ichelp.org/Page.aspx?pid=444.

The O’Leary-Sant Index is a measure of urinary and pain symptoms, and of how problematic the symptoms are for the patient.²⁶ The PUF questionnaire also incorporates an assessment of sexual function and the impact of the pain and urinary symptoms,²⁷ but it has not been validated.

The medical work-up

Perform a full gynecologic evaluation of female patients and a rectal examination of men. Include the following laboratory tests in your evaluation: complete blood count (CBC) with differential, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), total immunoglobulin E, and liver and thyroid function; test leuteinizing hormone and follicle-stimulating hormone levels for women, as well. Also include urine culture and sensitivity tests in the work-up.

Referral to a urologist is indicated if microscopic hematuria and pyuria are present or the patient’s symptoms are severe. The urologist may conduct a number of tests, for further evaluation or to confirm an IC/BPS diagnosis. These include:

Digital and manometric pelvic floor muscle examination. Manometry is performed using a vaginal or rectal pressure-sensitive probe that measures the strength of contraction and the ability to relax the pelvic floor muscles. In one study, 87% of women with IC/BPS were found to have levator muscle pain described as “consistent with pelvic floor dysfunction.”²⁸

Kaufman Q-tip touch sensitivity test. This involves touching all 4 quadrants of the vulvar and vestibular Skene’s gland ostia to evaluate for vestibulodynia, using a visual analog scale to document the level of pain and sensitivity the patient is experiencing.

Potassium sensitivity test. The physician instills a high concentration of potassium chloride into the bladder to evaluate how much pain it elicits.²⁷ (Although this test is frequently included in the evaluation of patients suspected of having IC/BPS, its use is controversial because it is unnecessarily painful, while its sensitivity and specificity are low.¹)