Epididymitis may be caused by several conditions, some more common than others.
Mechanisms:
(1) infectious including post-infectious and opportunistic
(2) immune
(3) drug-related
Sexually-transmitted diseases:
(1) Neisseria gonorrhoeae
(2) Chlamydia trachomatis
Bacteria:
(1) Group A Streptococcus
(2) Salmonella
(3) Klebsiella
(4) Brucella
Bacteria-like:
(1) Mycoplasma pneumonia
(2) Ureaplasma urealyticum
Virus:
(1) mumps
(2) cytomegalovirus
(3) enterovirus
(4) coxsackievirus
(5) adenovirus
Mycobacteria:
(1) M. tuberculosis
(2) M. bovis
Fungal:
(1) Histoplasma
(2) Coccidioidomycosis
(3) Candida
Parasitic:
(1) Schistosoma mansoni or haematobium
(2) Enterobius
(3) toxoplasmosis
Immune:
(1) Behcet's disease
(2) polyarteritis nodosa (PAN)
(3) Henoch-Schonlein purpura
Drug-induced:
(1) amiodarone
Other:
(1) Familial Mediterranean Fever (FMF)
(2) leukemic infiltration
(3) xanthogranulomatous