Pathogenesis (development of disease)
The following forms of orchitis can be distinguished:
- Hematogenous-metastatic – occurring as a complication of infectious diseases such as mumps (mumps virus), tuberculosis (Mycobacterium tuberculosis), with mumps orchitis being the most common cause
- Ascending (ascending infection) – via the ductus deferens (vas deferens) ascending infection in pre-existing urethritis (urethritis) or prostatitis (prostatitis).
- Posttraumatic – occurring after injury
Note: Isolated orchitis occurs much less frequently than epididymitis (inflammation of the epididymis). In contrast, in the context of a bacterial epididymitis in up to 90% of cases, a concomitant orchitis occurs as a result of germ ascension (“ascending infection”).
In addition to the above-mentioned forms of orchitis, there are also sterile testicular inflammations. These occur in association with systemic autoimmune diseases or pathogen-independent granulomatous inflammation.
Etiology (causes)
Biographic causes
- Age – in older age, subvesical obstruction with consecutive micturition difficulties is a possible cause of orchitis in combination with epididymitis (inflammation of the epididymis)
Behavioral causes
- Unprotected sexual intercourse (epididymitis).
Disease-related causes
Infectious and parasitic diseases (A00-B99).
- Bacterial infections (approximately 10% of cases):
- Brucellosis (generic term for diseases such as Bang’s disease or Malta fever caused by the genus Brucella; causative agent: gram-negative, aerobic rod-shaped bacteria of the genus Brucella).
- Syphilis (lues; a sexually transmitted disease); causative agent: bacterium Treponema pallidum spp. pallidum
- Tuberculosis (consumption; causative agent: Mycobacterium tuberculosis, an aerobic gram-positive rod bacterium).
- Typhoid fever (causative agent: typhoid bacterium (Salmonella enterica subsp. enterica serovar Typhi), a gram-negative, flagellated bacterium).
- Other bacteria such as chlamydia (among the most common sexually transmitted infections), E. coli, Klebsiella (e.g., Klebsiella pneumoniae), mycoplasma, Neisseria gonorrhoeae (gonorrhea, gonorrhea; a sexually transmitted disease), staphylococci, streptococci, etc.; these can lead to ascending/ascending infection
- Mycotic infections (fungi; very rare!) – Candida albicans, Histoplasma capsulatum.
- Viral infections:
- Mononucleosis (Pfeiffer’s glandular fever; causative agent: Epstein-Barr virus (EBV)).
- Mumps (causative agent: mumps virus) – orchitis occurs in about 18% of cases (in the absence of mumps vaccination) and usually about 5 to 10 days after parotitis (parotitis)
- Other viruses such as coxsackieviruses, echoviruses, rubella (rubella virus), influenza, varicella zoster virus (chickenpox and shingles), human immunodeficiency virus and others (Zika virus?).
- Parasitic infection:
- Malaria (pathogens: Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and Plasmodium knowlesi), Trichomonas vaginalis.
Injuries, poisonings, and other sequelae of external causes (S00-T98).
- Posttraumatic (occurring after injury) – genital trauma, vasectomy (male sterilization).
Further
- Systemic autoimmune diseases – Behçet’s disease, systemic lupus erythematosus, purpura Schönlein-Henoch and other vasculitides.
Medications
- Amiodarone
Environmental pollution – intoxications (poisonings).
- Heavy metals (e.g., mercury compounds).
