What are the causes of testicular pain?

Causes of Testicular Pain

Most Common Causes (85-90% of Cases)

The three most common causes of acute testicular pain are epididymitis/epididymo-orchitis, testicular torsion, and torsion of testicular appendage, which together account for approximately 85-90% of all cases. 1

Epididymitis/Epididymo-orchitis

• Most common cause in adolescents and adults, representing approximately 600,000 cases annually in the United States 1, 2
• Characterized by gradual onset of pain with a positive Prehn sign (pain relief when testicle is elevated) 1
• Ultrasound shows increased blood flow on Doppler and enlarged epididymis 1, 2
• In sexually active young adults, typically caused by C. trachomatis or N. gonorrhoeae; in men >35 years, enteric organisms predominate 3

Testicular Torsion

• Surgical emergency requiring intervention within 6-8 hours to prevent testicular loss 1, 2
• Presents with sudden onset of severe pain and negative Prehn sign (no pain relief with elevation) 1, 2
• Has a bimodal distribution with peaks in neonates and postpubertal boys, though can occur in adults 1, 2
• Ultrasound shows decreased or absent blood flow and the pathognomonic "whirlpool sign" of twisted spermatic cord 1, 2
• Critical pitfall: Testicular torsion is rare but not impossible in patients over 35 years, and delayed diagnosis can lead to testicular loss 2, 4

Torsion of Testicular Appendage

• Most common cause in prepubertal boys 1, 2
• May present with the pathognomonic "blue dot sign" (visible through skin), though this is only seen in 21% of cases 1, 2

Age-Stratified Approach

Prepubertal Boys

• Torsion of testicular appendage is the leading cause 1, 2
• Testicular torsion remains in the differential (neonatal peak) 2

Adolescents and Young Adults

• Epididymitis is most common overall 2
• Testicular torsion has its second peak in postpubertal boys and must be urgently excluded 1, 2
• In sexually active patients, consider STI-related epididymitis 3

Adults >35 Years

• Epididymitis overwhelmingly predominates 2
• Testicular torsion is rare but must still be considered if clinical presentation suggests it 2, 4

Less Common but Important Causes

Segmental Testicular Infarction

• Presents with a wedge-shaped avascular area on ultrasound, though may also appear as round lesions 2

Acute Idiopathic Scrotal Edema

• Rare, self-limiting condition primarily in prepubertal boys but can occur in adults 2
• Usually painless or minimally painful with marked scrotal wall thickening 2
• Diagnosis of exclusion 1

Tension Hydrocele

• Uncommon cause where large hydrocele compromises testicular perfusion 5
• Requires emergent operative drainage 5

Chronic Testicular Pain (Orchialgia)

• Defined as at least 3 months of chronic or intermittent pain 6
• Etiology is frequently idiopathic after excluding reversible causes (spermatocele, tumor, infection, varicocele) 7, 6
• Post-vasectomy pain may be due to functional obstruction or spermatic granuloma 7

Critical Clinical Pitfalls

• Significant overlap exists in clinical presentations between different causes, making diagnosis challenging 1, 2
• Normal urinalysis does not exclude either testicular torsion or epididymitis 2
• False-negative Doppler evaluations can occur with partial torsion or spontaneous detorsion 1, 2
• Trauma history can be misleading: progressive worsening pain with systemic symptoms suggests torsion rather than simple traumatic injury 1
• Never delay surgical consultation for imaging when clinical suspicion for torsion is high, as this risks testicular loss 1
• Testicular cancer should be included in the differential for persistent scrotal pain after completing antimicrobial treatment 3