What is the most likely diagnosis for a 10-year-old boy with sudden onset scrotal pain, nausea, and negative cremasteric reflex?

The diagnosis of testicular torsion is particularly relevant in this case due to the characteristic symptoms presented by the 10-year-old boy, including sudden onset scrotal pain, nausea, and a negative cremasteric reflex. Testicular torsion occurs when the spermatic cord becomes twisted, cutting off blood supply to the testicle. This condition often presents acutely, with severe pain usually localized to one side of the scrotum, and can also be associated with gastrointestinal symptoms like nausea due to the intensity of the pain.

The absence of the cremasteric reflex, which involves the contraction of the cremaster muscle upon stroking the inner thigh, supports this diagnosis, as it is commonly lost in cases of testicular torsion. Time is of the essence in this situation, as the viability of the affected testicle diminishes significantly within hours if blood flow is not restored, highlighting the urgency for intervention and management of this condition.

On the other hand, acute epididymitis generally presents with gradual onset of pain, swelling, and possible fever, often with a positive cremasteric reflex. A severe salmonella infection does not typically cause isolated scrotal pain and is less likely in this context. Acute orchitis often presents with swelling