What is the workup and management for penile swelling and pain in a pediatric patient?

Workup and Management of Penile Swelling and Pain in a 5-Year-Old

Immediate Assessment: Rule Out Emergencies First

In a 5-year-old with penile swelling and pain, immediately assess for penile fracture (rupture of corpus cavernosum), priapism, and urethral injury before considering other diagnoses. 1, 2

Emergency Red Flags to Identify

• Penile fracture: Look for ecchymosis, history of trauma (falling, straddle injury), and acute onset swelling—this requires immediate surgical exploration 1, 3
• Ischemic priapism: Completely rigid, painful erection lasting >4 hours—this is a medical emergency requiring immediate intracavernous treatment 1, 2
• Urethral injury: Blood at urethral meatus, gross hematuria, or inability to void—requires retrograde urethrogram or urethroscopy 1, 2

Critical Pitfall

Never delay surgical consultation for suspected penile fracture, as conservative management leads to worse long-term erectile dysfunction outcomes 2. Even in prepubertal children, corpus cavernosum rupture can occur from blunt trauma and requires urgent operative repair 3.

Diagnostic Workup Algorithm

Step 1: History and Physical Examination Specifics

Obtain these specific details:

• Exact timing of onset and progression of swelling 3, 4
• Any trauma history (falls, straddle injuries, zipper injuries) 1, 3
• Associated symptoms: fever, dysuria, hematuria, rash, joint pain, abdominal pain 4, 5
• Gastrointestinal symptoms (diarrhea, abdominal pain, weight loss) suggesting Crohn's disease 4, 6
• Recent upper respiratory infection or rash suggesting Henoch-Schönlein purpura 5

Physical examination must include:

• Palpation of both testicles to rule out testicular torsion 2, 7
• Assessment of penile rigidity (completely rigid vs. tumescent) 1, 2
• Inspection for ecchymosis, purpura, or skin lesions 1, 4, 5
• Scrotal examination for swelling or tenderness 3, 4
• Examination of buttocks and lower extremities for purpuric rash 5

Step 2: Initial Diagnostic Testing

If trauma history or acute presentation:

• Ultrasound of penis to assess for corpus cavernosum discontinuity 1, 3
• Retrograde urethrogram if blood at meatus or inability to void 1, 2
• Urinalysis for hematuria 1, 5

If no clear trauma and subacute/chronic presentation:

• Complete blood count, inflammatory markers (ESR, CRP) 4, 6
• Urinalysis and urine culture to exclude infection 4
• Consider skin biopsy if chronic swelling with no clear etiology—may reveal granulomatous inflammation of Crohn's disease 4, 6

Step 3: Consider Non-Traumatic Etiologies

Crohn's disease (metastatic Crohn's):

• In 88% of pediatric cases, genital swelling precedes gastrointestinal symptoms 4
• Diagnosis requires biopsy showing granulomatous inflammation 4, 6
• Evaluation for underlying Crohn's disease is necessary in all patients with unexplained genital swelling 4

Henoch-Schönlein purpura:

• Look for purpuric rash on buttocks/lower extremities, arthralgia, abdominal pain 5
• Penile involvement is rare but documented in pediatric cases 5
• Diagnosis is clinical; biopsy shows leukocytoclastic vasculitis if needed 5

Priapism in sickle cell disease:

• Stuttering priapism episodes lasting <4 hours are common in children with sickle cell disease 1
• Treat with hydration and analgesia at home unless duration >4 hours 1
• Episodes >4 hours require emergency intracavernous treatment to prevent irreversible tissue damage 1

Management Based on Diagnosis

Traumatic Injury (Penile Fracture)

Perform immediate surgical exploration and repair through ventral midline or circumcision incision with absorbable suture tunical repair. 1, 2 Flexible cystoscopy should be performed intraoperatively to assess urethral integrity 3.

Ischemic Priapism

Provide immediate intracavernous sympathomimetic treatment (phenylephrine) with concurrent hydration and analgesia. 1, 2 Do not rely on systemic therapy alone 2.

Infectious Causes (If Purulent Discharge Present)

This is extremely rare in prepubertal children, but if suspected:

• Obtain urethral swab for culture 8
• Empiric antibiotics: ceftriaxone 50 mg/kg (max 1g) IM once PLUS doxycycline if age >8 years 1, 8
• For age <8 years, use azithromycin instead of doxycycline 1

Crohn's Disease

Initiate systemic immunosuppressive therapy (azathioprine or anti-TNF agents) targeting the underlying inflammatory bowel disease. 4, 6 Topical therapies are ineffective 4. Gastroenterology consultation is mandatory 4, 6.

Henoch-Schönlein Purpura

Provide supportive care with NSAIDs for pain control and monitor for renal involvement with serial urinalysis. 5 Penile swelling typically resolves spontaneously without specific intervention 5.

Non-Ischemic Priapism

Observe at home for up to 4 weeks as this is NOT an emergency. 2 The penis will be tumescent but not completely rigid and non-painful 1, 2.

Follow-Up and Monitoring

• Post-surgical repair: Follow-up within 1 week to assess wound healing 3
• Crohn's disease: Reassess at 3 months; expect pain resolution and lesion reduction with appropriate immunosuppression 4, 6
• HSP: Monitor urine for proteinuria/hematuria for 6 months 5
• Priapism: Surveillance for recurrent episodes and erectile function assessment 1

Key Pitfalls to Avoid

• Never assume penile swelling in a child is benign without ruling out trauma-related corpus cavernosum rupture 3
• Do not confuse non-ischemic priapism (tumescent, non-painful) with ischemic priapism (rigid, painful)—only the latter is an emergency 1, 2
• Always evaluate for Crohn's disease in unexplained chronic genital swelling, even without gastrointestinal symptoms 4, 6
• Do not delay surgical exploration for suspected penile fracture to obtain imaging if clinical diagnosis is clear 1, 2