65 - Prehn's sign

- Prehn's sign is a medical diagnostic indicator that helps determine whether the presenting injured testicle is caused by acute epididymitis or from testicular torsion.

- According to Prehn's sign, the physical lifting of the testicles relieves the pain of epididymitis but not pain caused by testicular torsion.

* Negative Prehn's sign indicates no pain relief with lifting the affected testicle, which points towards testicular torsion which is a medical emergency and must be relieved within 6 hours.

* Positive Prehn's sign indicates there is pain relief with lifting the affected testicle, which points towards epididymitis.

1: Epididymis
2: Head of epididymis
3: Lobules of epididymis
4: Body of epididymis
5: Tail of epididymis
6: Duct of epididymis
7: Deferent duct (ductus deferens or vas deferens)
EPONYMS IN MEDICINE, 1994 DESK DIARY