A 15-year-old high school football player is brought to your office by his mother. He is complaining of severe testicular pain since exactly 8:00 this morning. He denies any sexual activity and states that he hurts so bad he can't even urinate. He is nauseated and is throwing up. He denies any recent illness or fever. His past medical history is unremarkable. He denies any tobacco, alcohol, or drug use. His parents are both in good health. On examination, you see a young teenager lying on the bed with an emesis basin. He is very uncomfortable and keeps shifting his position. His blood pressure is 150/100, his pulse is 110, and his respirations are 24. On visualization of the penis, he is circumcised and there are no lesions and no discharge from the meatus. His scrotal skin is tense and red. Palpation of the left testicle causes severe pain and the patient begins to cry. His prostate examination is unremarkable. His cremasteric reflex is absent on the left but is normal on the right. By catheter you get a urine sample and the analysis is unremarkable. You send the boy with his mother to the emergency room for further workup.