Epidemiology - Peak incidence in first year of life and during puberty; Can occur at any age.

Mechanism - 50% occur during sleep; Can occur during trauma as well. 

Risk factors - Bell-clapper deformity or undescended testes. 

Clinical: 

• acute onset testicular pain, associated nausea and vomiting. 
• can present with isolated lower abdominal pain or flank pain. 
• exam findings are not very sensitive
• cremasteric reflex
• phren's sign does not rule out torsion
• swollen testes, transverse lie. 
• blue dot sign pathognomonic for torsion of appendix testis. 

Management:

• History and physical exam are insufficient to rule out testicular torsion - ultrasound. 
• stat urology consult.
• UA
• consider manual detorsion depending on urology consultation. 

How We Miss Torsion:

• One of the four most common sources of pediatric malpractice litigation. 
• Failing to recognize it can occur after puberty. 
• atypical presentations like lower abdominal pain.
• not examining the testicles in every GU and lower abdominal pain complaint. 
• false negative torsion is a common theme in litigated and missed torsion cases - if negative ultrasound but high clinical suspicion consult urology.