How should swelling of the penile shaft in an 8-year-old boy be evaluated and managed?

Evaluation and Management of Penile Shaft Swelling in an 8-Year-Old

In an 8-year-old boy with penile shaft swelling, immediately assess for trauma history and perform urgent evaluation to rule out corpus cavernosum rupture (penile fracture), which requires emergency surgical repair within hours to prevent permanent complications including erectile dysfunction and fibrosis.

Initial Clinical Assessment

Critical History Elements

• Trauma mechanism: Ask specifically about falls, straddle injuries, or direct penile trauma 1, 2
• Onset and timing: Acute onset with immediate swelling suggests traumatic injury, while gradual onset may indicate inflammatory or infectious causes 2
• Associated symptoms:
  • Ecchymosis, cracking/snapping sound, or immediate pain suggests corpus cavernosum rupture 3, 1
  • Fever, erythema, or systemic symptoms suggest infectious cellulitis 4
  • Gastrointestinal symptoms (diarrhea, abdominal pain) may indicate Crohn's disease with metastatic genital involvement 5

Physical Examination Priorities

• Inspect for ecchymosis and swelling pattern: Penile shaft ecchymosis with swelling is the hallmark of corpus cavernosum rupture 3, 1
• Palpate testicular position and tenderness: Both testicles should be palpable and nontender; rule out concurrent scrotal pathology 1
• Assess for urethral injury: Check for blood at the meatus, inability to void, or gross hematuria, which mandate urethral evaluation 3
• Evaluate skin integrity: Look for erythema, warmth, or skin changes suggesting cellulitis or inflammatory conditions 2, 4

Diagnostic Algorithm Based on Clinical Presentation

If Trauma History with Acute Swelling and Ecchymosis

This is a urologic emergency requiring immediate action:

• Obtain urgent scrotal/penile ultrasound with Doppler to assess for discontinuity of the corpus cavernosum 1
• Perform flexible cystoscopy if blood at meatus, hematuria, or inability to void to evaluate for urethral injury 3, 1
• Proceed directly to surgical exploration if ultrasound shows corpus cavernosum rupture or if clinical suspicion remains high despite equivocal imaging 3

Critical pitfall: Although corpus cavernosum rupture is rare in prepubertal children, it can occur from non-sexual trauma such as falls onto railings or straddle injuries 1. Delayed recognition leads to permanent complications including penile angulation, erectile dysfunction, and fibrosis 1.

If Gradual Onset Without Clear Trauma

Consider broader differential diagnosis:

• Infectious cellulitis: Presents with erythema, warmth, and rapid fluid accumulation; requires immediate penicillin therapy and potential surgical decompression if compartment syndrome develops 4
• Metastatic Crohn's disease: Genital swelling often precedes gastrointestinal symptoms in 88% of pediatric cases; evaluate for concurrent GI complaints and consider biopsy if diagnosis unclear 5
• Benign smegma pearls: Yellowish nodules in uncircumcised boys without pain or systemic symptoms; require only parental reassurance and monitoring 6

Urgent Imaging Protocol

When ultrasound is indicated (trauma cases or unclear etiology):

• Grayscale examination: Look for discontinuity of corpus cavernosum, heterogeneous echotexture, or fluid collections 7, 1
• Color Doppler assessment: Evaluate testicular perfusion to rule out concurrent testicular injury 1
• Compare to contralateral side: Use as internal control for normal anatomy 7

Management Based on Diagnosis

Corpus Cavernosum Rupture (Penile Fracture)

Immediate surgical repair is mandatory:

• Timing is critical: Surgical exploration and repair within hours significantly reduces complications 3, 8
• Surgical approach: Expose injured corpus cavernosum through ventral midline or circumcision incision; repair tunica with absorbable suture 3
• Concurrent urethral evaluation: Perform if any signs of urethral injury present 3, 1

Infectious Cellulitis

Aggressive medical and potential surgical management:

• Immediate IV penicillin for streptococcal cellulitis 4
• Linear incisions for decompression if compartment syndrome develops between Colles' and Buck's fascia to prevent skin gangrene 4
• Monitor closely for progression requiring debridement 4

Inflammatory Conditions (Suspected Crohn's Disease)

Systemic evaluation and treatment:

• Evaluate for gastrointestinal symptoms even if absent initially, as genital manifestations typically precede intestinal symptoms 5
• Consider gastroenterology referral for formal CD workup 5
• Systemic medications for underlying CD are most effective for genital manifestations 5

Common Pitfalls to Avoid

• Do not dismiss trauma history in prepubertal children: Corpus cavernosum rupture can occur from non-sexual mechanisms 1
• Do not delay surgical exploration if clinical suspicion for penile fracture is high, even with equivocal imaging 3
• Do not overlook urethral injury: Always evaluate for blood at meatus, hematuria, or voiding difficulty in trauma cases 3, 1
• Do not assume infectious cause without proper evaluation: Genital swelling may be the first manifestation of systemic disease like Crohn's 5