Orchitis

Inflammation of one or both testes, characterized clinically by testicular pain, swelling, tenderness, and sometimes erythema or systemic inflammatory symptoms.

Causes

• Viral infectious causes

  • Mumps virus (most common viral cause of orchitis)

  • Rubella virus

  • Varicella-zoster virus (chickenpox/shingles)

  • Cytomegalovirus

  • Echovirus

• Bacterial infectious causes

  • Sexually transmitted infections: Chlamydia trachomatis, Neisseria gonorrhoeae

  • Urinary tract pathogens: Escherichia coli, Gram negative bacteria

  • Skin and soft tissue organisms: Staphylococcus, Streptococcus

• Genitourinary causes

  • Epididymitis progressing to epididymo-orchitis

  • Urethritis-associated infections

  • Prostatitis with ascending bacterial spread

• Systemic and inflammatory causes

  • Autoimmune orchitis

  • Sarcoidosis

  • Vasculitic disorders affecting testicular tissue

• Other causes

  • Post-infectious immune-mediated inflammation

  • Trauma-associated inflammation

  • Rare drug-induced or granulomatous orchitis