A patient with scrotal pain undergoes testicular ultrasound to evaluate primarily for the presence of testicular torsion.  

 Although torsion is common, epididimytis or epididymo-orchitis is more common even in prepubertal boys.    

 Epididymitis is usually bacterial involving organisms such as staphylococcus, streptococcus, proteus, chlamydia and N. gonorrhea.  

In a minority of patients the infection spreads to the testicle. 

Isolated orchitis is rare and usually viral(mumps) or post-traumatic.     

Patients with epididymitis or epididymo-orchitis usually present with pain over a 1-2 day period, are often febrile, possibly with dysuria or pyuria.    

Color Doppler ultrasound is usually easily able to distinguish torsion which should demonstrate diminished flow to the affected testicle from infection which demonstrates increased flow, +/- enlargement, =/- altered echogenicity. 

 Hydroceles may occur with either entity.

     Other causes of scrotal pain such as tumors, varices, or incarcerated hernia can also be distinguished.  

Complications of epididymo-orchitis include abscess, pyocele and testicular infarction. 

TAKE HOME MESSAGE:

When seen in infants and young children search for: Ectopic ureter

 Ectopic vas deferens

 Prostatic utricle

 Urethral duplication

 Posterior urethral valves

 Urethrorectal fistula

 Detrusor muscle dyssynergia( Hinmann syndrome)

Vesicoureteral reflux 

Prehn sign: Elevation of the affected hemiscortum relieves the pain of epididymitis and exacerbates the pain of torsion.