Demographics: ♀ > ♂ (ratio ~5:1); most common in middle-aged adults (onset typically > 30 yo).
Associated Conditions: Strongly linked to chronic pain and somatic symptom disorders:
Fibromyalgia
Irritable Bowel Syndrome (IBS)
Chronic fatigue syndrome
Endometriosis
Anxiety and depressive disorders
Clinical Features
Pelvic / Suprapubic Pain: Chronic pelvic pain (> 6 wks duration) that is exacerbated by bladder filling and classically relieved by voiding. c
Lower Urinary Tract Symptoms (LUTS):
Marked urinary frequency (often > 8–10 times/day, up to 60 times/day in severe cases).
Urinary urgency.
Nocturia.
Sexual Dysfunction: Dyspareunia (frequently aggravated in the days following intercourse).
Physical Examination:
Tenderness on palpation of anterior vaginal wall or suprapubic area.
Absence of abnormal discharge, cervical motion tenderness, or adnexal masses.
Diagnosis
Clinical diagnosis of exclusion (persistent symptoms > 6 wks without identifiable underlying pathology/infection).
Initial / Screening:
Urinalysis (UA) & Urine Culture: Normal; persistently negative for infection (no nitrites, negative leukocyte esterase, sterile culture). Microscopic hematuria may occasionally be present.
STI Screening: Urine NAAT for Chlamydia trachomatis and Neisseria gonorrhoeae to exclude urethritis/cervicitis.
Key Labs:
Urine Cytology: Indicated in pts with hematuria and high risk for urothelial carcinoma (e.g., age > 50, smoking history).
Confirmatory / Specialized Testing:
Testing generally unnecessary for uncomplicated presentations.
Cystoscopy: Performed if diagnosis is ambiguous or to rule out malignancy.
Hunner lesions (erythematous mucosal patches with small central vessels/scars; pathognomonic but seen in only 10–20% of cases).
Glomerulations (petechial mucosal hemorrhages after hydrodistension; non-specific).
Post-Void Residual (PVR): Normal (rules out urinary retention).
Differential Diagnostics
Urinary Tract Infection (UTI): Diff by acute onset (days vs > 6 wks), pyuria, bacteriuria, and positive urine culture.
Urothelial (Bladder) Carcinoma: Diff by painless gross/microscopic hematuria, positive urine cytology, mass lesion on cystoscopy/CT, and absence of pain relief with voiding.
Overactive Bladder (OAB): Diff by lack of associated pelvic/bladder pain; primarily urgency incontinence and frequency without pain relieved by bladder emptying.
Endometriosis: Diff by cyclical/catamenial pelvic pain, dysmenorrhea, and lack of direct relationship to bladder filling.
Urethritis: Diff by presence of urethral discharge, dysuria localized directly to the urethra (rather than suprapubic discomfort), and positive NAAT.
Pelvic Inflammatory Disease (PID): Diff by fever, purulent cervical discharge, cervical motion tenderness, and elevated inflammatory markers (ESR/CRP).
Pelvic Floor Physical Therapy (PFPT): Myofascial physical therapy for hypertonic pelvic floor (Kegel exercises are contraindicated as they worsen hypertonicity).
Amitriptyline (TCA): First-line medication; acts via neuromodulation and anticholinergic effects to decrease frequency and nocturnal pain.
Pentosan Polysulfate Sodium (PPS): Oral agent designed to restore the damaged glycosaminoglycan (GAG) layer of the urothelium (requires 3–6 months for clinical effect; monitor for maculopathy/retinal toxicity).
Antihistamines: Hydroxyzine (helpful in pts with allergic diathesis).
Intravesical Therapy: Direct bladder instillation of dimethyl sulfoxide (DMSO), heparin, or lidocaine/bicarbonate.
Refractory / Interventional Therapy:
Cystoscopy with Hydrodistension: Provides transient symptom relief in refractory cases.
Lesion-Directed Therapy: Fulguration or triamcinolone injection of Hunner lesions.
Neuromodulation: Sacral neuromodulation (SNS) for refractory pain and frequency.
Intradetrusor OnabotulinumtoxinA: Injections to reduce severe urgency/frequency.
Major Surgery: Urinary diversion with or without cystectomy (rare, last resort for end-stage contracted bladder).
Complications
Significant reduction in health-related quality of life (impaired work productivity, high rates of major depression/suicidality).
Chronic sleep deprivation secondary to severe nocturia.
Sexual dysfunction and secondary relationship distress.
Small-capacity fibrotic bladder (fibrous contraction of the detrusor muscle in end-stage chronic disease).