This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Reproductive Medicine and Sexual Dysfunction, Subject name: Surgery
40 year old man is suffering from fever & pain in the scrotum which is not relieved by elevation of testis. 3 days before he had sexual contact with a young female : 
Select and explain. 
A. Testicular tumour, B. Acute epididymitis, C. Torsion of testis, D. Acute orchitis
C: Torsion of testis
Answer: C: Torsion of testis 
Explanation: Ans. is 'c' ie Torsion of testis Torsion of testis can be differentiated from acute epididymitis by Prehn's sign. ie. On elevation of testis the pain increases in - Torsion On elevation of testis the pain decreases in -- epididymo-orchitis. Don't be confused with fever, it can also occur in torsion, especially in older patients.