The following patient characteristics were assessed: time between onset of pain and arrival at the ED, characteristics and localization of pain, and Prehn's sign (positive or negative).
To assess factors that help to distinguish between genital/paragenital infection and testicular torsion, simple and multiple binary logistic regression analyses were performed on the different laboratory parameters (CRP </> 3 ml/L, WBC </> 10.4 g/L, </> 4 WBC per field in urine, </> 4 Ec per field in urine), time between onset of pain and arrival in the ED, characteristics of pain, localization of pain, and Prehn's sign (positive or negative).
Thirty-three percent (14/42) of patients with testicular torsion had a positive Prehn's sign at presentation, 19.0% (8/42) had no cremaster reflex, and 54.7% (23/42) had a retained testis unilaterally.
A positive Prehn's sign was an independent predictor of testicular torsion, whereas color Doppler ultrasound was not [Table 3].
We demonstrated that no single factor can reliably predict the cause of an acute scrotum, but rather a combination of factors, including patient history (characteristics of pain, dysuria), clinical findings (fever, Prehn's sign), and laboratory tests (CRP and WBC in blood, WBC in urine).