What are the differential diagnoses for acute testicular pain in a male?

Differential Diagnosis for Testicular Pain

The differential diagnosis for acute testicular pain includes three conditions that account for 85-90% of cases: testicular torsion, epididymitis/epididymoorchitis, and torsion of testicular appendage, with age being the primary factor determining likelihood 1.

Age-Stratified Approach to Differential Diagnosis

Prepubertal Boys

• Torsion of testicular appendage is the most common cause 1
• Testicular torsion (bimodal peak in neonates and postpubertal boys)
• Epididymitis (uncommon, but associated with UTIs and structural abnormalities)

Adolescents and Adults

• Epididymitis/epididymoorchitis is the most common cause 1
• Testicular torsion (second bimodal peak in postpubertal boys, decreases with age but can occur at any age)
• Torsion of testicular appendage

Complete Differential Diagnosis List

Surgical Emergencies (Time-Critical)

• Testicular torsion - requires surgical exploration within 6-8 hours to prevent testicular loss 1
• Fournier gangrene 1
• Strangulated inguinal hernia 1
• Scrotal abscess 1
• Testicular trauma with rupture 2

Inflammatory/Infectious Causes

• Epididymitis 1
• Epididymoorchitis 1
• Orchitis 1
• Inflammation of tunica vaginalis 1

Anatomical/Structural Causes

• Torsion of testicular appendage 1
• Hydrocele 1
• Idiopathic scrotal edema 1
• Epididymal cysts 1
• Varicocele 3

Neoplastic

• Testicular tumors 1

Other

• Trauma 1
• Vasculitis syndromes (e.g., Henoch-Schönlein purpura) 3

Critical Clinical Distinctions

Testicular Torsion vs. Epididymitis

Onset timing:

• Torsion: sudden, acute onset (minutes to hours)
• Epididymitis: gradual, insidious onset over 1-2 days 1

Prehn sign:

• Positive (pain relief with testicular elevation): suggests epididymitis 1
• Negative (no pain relief): suggests torsion 1

Age distribution:

• Torsion: bimodal (neonates and postpubertal boys, incidence 2.9-3.8 per 100,000 boys <18 years) 1
• Epididymitis: predominantly adolescents and adults (1 in 44 outpatient visits in men 18-50 years) 1

Torsion of Testicular Appendage

"Blue dot sign":

• Pathognomonic when present (visualization of infarcted appendage through skin) 1
• Only seen in 21% of cases due to rapid scrotal edema 1

Location:

• Focal tenderness over upper pole of testis 1

Critical Pitfall

The most important pitfall is missing testicular torsion, as it requires surgical exploration within 6-8 hours to prevent irreversible testicular loss 1. The overlapping clinical presentations between torsion, epididymitis, and appendage torsion make this challenging 1. When diagnosis is equivocal despite clinical evaluation and imaging, immediate surgical exploration is warranted to avoid missing torsion 4.