What are the causes of penile bleeding?

Causes of Penile Bleeding

Penile bleeding most commonly results from trauma (including penile fracture, penetrating injury, or urethral injury), superficial dorsal vein rupture, or infectious/inflammatory conditions like Fournier gangrene, and requires immediate evaluation to distinguish surgical emergencies from benign conditions.

Traumatic Causes (Most Common and Urgent)

Penile Fracture with Urethral Injury

• Penile fracture occurs from forceful bending of the erect penis, causing rupture of the tunica albuginea, and is associated with urethral injury in 10-22% of cases 1
• Classic presentation includes an audible "pop" or "snap," rapid detumescence, penile ecchymosis, and blood at the urethral meatus if the urethra is involved 1, 2
• Surgical exploration and repair is mandatory and associated with lower risk of erectile dysfunction and penile curvature compared to conservative management 1
• Ultrasound or MRI can clarify diagnosis in equivocal cases, but clinical history is usually sufficient 1

Penetrating Penile Injuries

• Penetrating injuries are associated with concomitant urethral injuries in 11-29% of cases 1
• All but the most superficial injuries should be evaluated for urethral injury, explored surgically, and repaired 1
• Blood dripping from the meatus indicates urethral involvement requiring immediate urologic consultation 1

Pelvic Fracture Urethral Injury (in females: labial edema/vaginal vault blood)

• Posterior urethral injuries from pelvic fractures present with blood at the meatus and inability to void 1
• Securing catheter drainage is the immediate goal, though suprapubic tube placement may be necessary 1

Vascular Causes (Non-Traumatic)

Superficial Dorsal Vein Rupture (Mondor's Disease)

• Rare condition presenting as sudden, indurated swelling of the dorsal penile vein with possible bleeding if skin integrity is compromised 3, 4
• Usually occurs after vigorous sexual activity or manipulation of erect penis 3, 5
• Conservative therapy with heparin ointment (10,000 IU) and oral anti-inflammatory agents for 14 days achieves recovery in >92% of cases 5
• Thrombectomy is indicated only if conservative therapy fails after 2 weeks 5

Infectious/Necrotizing Causes (Life-Threatening)

Fournier Gangrene

• Necrotizing soft-tissue infection involving scrotum and penis that can present with bleeding from necrotic tissue 1
• Mean age of onset is 50 years; most patients have diabetes or other significant underlying disease 1
• Requires aggressive surgical debridement, broad-spectrum antibiotics covering mixed aerobic and anaerobic flora (including Staphylococci and Pseudomonas), and intensive care support 1
• Infection spreads along fascial planes from perianal/retroperitoneal sources or urinary tract infections 1

Priapism-Related Bleeding

Ischemic Priapism Complications

• While priapism itself doesn't cause bleeding, invasive procedures for treatment (aspiration, phenylephrine injection, surgical shunting) can result in bleeding 6, 7
• All patients with priapism >4 hours require emergent evaluation with cavernous blood gas analysis (pO₂ <30 mmHg, pCO₂ >60 mmHg, pH <7.25 confirms ischemic type) 6, 7
• Delayed treatment beyond 24-48 hours results in widespread necrosis and permanent erectile dysfunction 6, 7

Critical Diagnostic Algorithm

When evaluating penile bleeding, immediately determine:

1. Trauma history: Recent sexual activity, manipulation, or blunt/penetrating injury suggests fracture or penetrating trauma requiring surgical exploration 1

2. Blood location:

   • Blood at meatus = urethral injury until proven otherwise 1, 2
   • Subcutaneous bleeding/ecchymosis = tunica albuginea rupture or vein thrombosis 1, 3
   • Skin necrosis with bleeding = consider Fournier gangrene 1

3. Associated findings:

   • Fever, systemic toxicity, crepitus = necrotizing infection requiring emergency surgery 1
   • Persistent erection = priapism requiring blood gas analysis 6, 7
   • Palpable cord-like structure = dorsal vein thrombosis, usually benign 5

Common Pitfalls to Avoid

• Never delay urologic consultation for penile trauma with blood at meatus—urethral injury requires immediate surgical evaluation 1
• Do not assume all penile bleeding is benign; failure to recognize Fournier gangrene early results in high mortality 1
• Avoid performing retrograde urethrography in the emergency department without urology involvement if penile fracture is suspected—this delays definitive surgical repair 1
• Do not treat suspected penile fracture conservatively; surgical repair within 24 hours provides best functional outcomes 1