Last revised by Jeremy Jones on 20 Sep 2021

Orchitis (plural: orchitides) is an infection of the testis, which is rarely isolated, and when in conjunction with the epididymis is called epididymo-orchitis.

Usually, bacteria retrogradely seed into the testis from the bladder or prostate. It can also be secondary to viral infection (e.g. mumps, Coxsackie virus). 

Ultrasound is the gold standard investigation. When compared with the other testis in the 'sunglasses view' features of orchitis include relative: 

  • hypoechogenicity: focal or diffuse
  • hypervascularity: focal or diffuse
  • swelling
  • scrotal wall thickening

A complex/septated hydrocele can be seen in the ipsilateral scrotum

  • intermittent testicular torsion 5
    • reperfusion after intermittent torsion can present similarly on Doppler ultrasound with increased flow, but the patient's history allows differentiation
  • primary testicular malignancy should be considered, especially with focal changes

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Case 1
    Drag here to reorder.
  • Case 2: with a pyocele
    Drag here to reorder.
  • Case 3
    Drag here to reorder.