What is the diagnosis and treatment for a child or young adult with a history of allergies and asthma presenting with eosinophilic cystitis?

Eosinophilic Cystitis: Diagnosis and Treatment

Diagnostic Approach

Cystoscopy with bladder biopsy is mandatory to establish the diagnosis of eosinophilic cystitis, as there is no pathognomonic clinical presentation or typical endoscopic appearance. 1, 2

Clinical Presentation

The condition presents with variable symptoms depending on age:

• In children (particularly infants): Suprapubic mass and bilateral hydroureteronephrosis are common presentations 2
• In older children and adults: Urinary frequency (67%), dysuria (62%), gross or microscopic hematuria (68%), suprapubic pain (49%), and urinary retention (10%) 1
• Gender distribution: Equal between males and females overall, but boys are affected more frequently than girls in the pediatric population (14% vs 7%) 1

Diagnostic Workup

Perform the following evaluations:

• Cystoscopy with biopsy (essential and diagnostic): Look for eosinophilic infiltration of the bladder wall; endoscopic findings may include petechiae, pseudotumor lesions, or normal-appearing mucosa 1, 2, 3
• Peripheral blood eosinophil count: Present in only 43% of cases, so absence does not exclude diagnosis 1
• Urinalysis and culture: Positive cultures found in 26% of patients 1
• Upper tract imaging (ultrasound or IVU): Essential to evaluate for hydronephrosis, which occurs in 27% of cases 1, 4
• Allergy history: Document history of asthma, allergies, or other atopic conditions 1, 2

Treatment Algorithm

First-Line Medical Management

The optimal treatment is transurethral resection of bladder lesions (when pseudotumor present) combined with corticosteroids and antihistamines. 1

Specific regimen:

• Corticosteroids: Prednisone 1-2 mg/kg/day (maximum 60 mg) for 8-12 weeks 5, 4
• Antihistamines: Add as adjunctive therapy 1, 2
• Antibiotics: Only when urinary tract infection is documented or upper tract dilation exists 1

Treatment Based on Presentation

For pseudotumor lesions:

• Perform transurethral resection followed by medical therapy with corticosteroids and antihistamines 1, 3

For non-mass lesions (petechiae or normal-appearing mucosa):

• Initiate oral corticosteroids and antihistamines without surgical intervention 4, 3

For minimally symptomatic cases:

• Consider conservative management with nonsteroidal anti-inflammatory drugs and observation 3

Management of Complications

Unilateral or bilateral hydronephrosis:

• Conservative management is appropriate with medical therapy alone 4
• Reserve surgical intervention for refractory cases with persistent upper tract obstruction 1

Refractory disease despite standard therapy:

• Consider low-dose cyclosporine (immunosuppressive therapy) for cases unresponsive to corticosteroids, antihistamines, and other conventional treatments 6
• Total cystectomy is reserved only for patients with unresponsive disease and persistent severe hematuria 1

Monitoring and Follow-up

• Clinical response: Symptoms typically improve within 7 days of initiating corticosteroid therapy 5
• Histological assessment: Repeat cystoscopy with biopsy at 8-12 weeks to evaluate treatment response 5, 7
• Upper tract surveillance: Serial imaging to monitor for resolution of hydronephrosis 4
• Recurrence monitoring: Recurrence is frequent, requiring long-term follow-up even after successful initial treatment 1, 2

Critical Pitfalls to Avoid

• Do not rely on peripheral eosinophilia for diagnosis, as it is absent in 57% of cases 1
• Do not delay cystoscopy and biopsy based on clinical suspicion alone; histological confirmation is essential 1, 2
• Do not perform total cystectomy as initial treatment; reserve for truly refractory cases with severe hematuria 1
• Do not overlook upper tract evaluation, as hydronephrosis occurs in over one-quarter of patients 1, 4