What is the differential diagnosis for a patient presenting with testicular pain?

Differential Diagnosis for Testicular Pain

The differential diagnosis for testicular pain includes three primary conditions that account for 85-90% of cases: epididymitis/epididymo-orchitis (most common overall), testicular torsion (surgical emergency), and torsion of testicular appendage (most common in prepubertal boys). 1, 2

Age-Stratified Differential Considerations

Adults (>25 years)

• Epididymitis/epididymo-orchitis is overwhelmingly the most common cause, representing approximately 600,000 cases annually in the United States 3
• In sexually active young adults, causative organisms are typically Chlamydia trachomatis or Neisseria gonorrhoeae 4
• In men >35 years, enteric organisms predominate 4
• Testicular torsion is rare in patients >35 years of age 3

Adolescents and Young Adults (19-25 years)

• Epididymitis remains most common in this age group 3
• Testicular torsion has a peak incidence in postpubertal boys, with an estimated yearly incidence of 2.9-3.8 per 100,000 boys under 18 years 1
• Torsion accounts for 10-15% of acute scrotal disease in children and results in a 42% orchiectomy rate when surgery is performed 5

Prepubertal Boys

• Torsion of testicular appendages is the most common cause in this population 3, 1
• The pathognomonic "blue dot sign" is only visible in 21% of cases 1, 2
• Testicular torsion also occurs with a neonatal peak in the bimodal distribution 1

Key Clinical Distinguishing Features

Testicular Torsion (Surgical Emergency)

• Abrupt onset of severe scrotal pain 3
• Negative Prehn sign (pain NOT relieved with testicular elevation) 1, 4
• Nausea and vomiting are common 6
• High-riding testicle with absent cremasteric reflex 5
• Critical time window: 6-8 hours before permanent ischemic damage occurs 1, 5
• Normal urinalysis does not exclude torsion 3

Epididymitis/Epididymo-orchitis

• Gradual onset of pain 3
• Positive Prehn sign (pain relief with testicular elevation) 4, 2
• May have abnormal urinalysis, though normal urinalysis does not exclude epididymitis 3
• Increased blood flow on Doppler ultrasound 4, 2

Torsion of Testicular Appendage

• Can mimic testicular torsion or epididymo-orchitis 3
• "Blue dot sign" when present is pathognomonic but infrequently encountered 3, 1
• Most common in prepubertal boys 3, 2

Additional Differential Considerations

Less Common but Important Causes

• Varicocele with pain: Affects 2-10% of the 15% of men with varicocele; pain is typically dull, aching, or throbbing 7
• Testicular tumor: Must be included in differential for persistent scrotal pain after completing antimicrobial treatment 4
• Strangulated inguinal hernia 6
• Traumatic hematoma or testicular fracture (when trauma history present) 6
• Segmental testicular infarction: Classic wedge-shaped avascular area on ultrasound 3
• Acute idiopathic scrotal edema: Rare, self-limiting, usually painless with marked scrotal wall thickening; diagnosis of exclusion 3

Critical Clinical Pitfalls

Overlapping presentations: There is significant overlap in clinical presentation between different causes of acute scrotal pain, making diagnosis challenging 3, 2

False-negative Doppler: Can occur with partial torsion or spontaneous detorsion, so high clinical suspicion should prompt surgical exploration regardless of imaging 1, 4

Time-critical nature: When testicular torsion cannot be confidently excluded by history and physical examination, immediate urological consultation is indicated—imaging should NOT delay surgical exploration 1, 8, 5

Chronic orchialgia: For pain lasting ≥3 months, consider chronic scrotal content pain involving epididymis, vas deferens, or paratesticular structures; etiology is frequently idiopathic 9