Obtain a sexual history, when appropriate. The onset of scrotal pain and edema is acute. As mumps orchitis is responsible for most cases of isolated orchitis, diagnosis in the ED usually is based on a reported history of a recent mumps infection or parotitis with a presentation of testicular edema. Other rare viral etiologies include Coxsackie virus, infectious mononucleosis, varicella, and echovirus. Bacterial orchitis rarely occurs without an associated epididymitis.
Patients are usually sexually active and present with a gradual onset of pain and edema.
Diagnosing mumps orchitis can be comfortably made based on history and physical examination alone. However, if there is a question of epididymo-orchitis, urine dip, urinalysis, and urethral cultures should be obtained. Diagnosing mumps orchitis can be confirmed with serum immunofluorescence antibody testing. As orchitis often presents as acute edema and pain of the testicle, it is critical to rule out testicular torsion. If torsion is likely or if several hours have passed before the patient arrives in the ED, operative exploration is indicated.