Epididymitis

Epididymitis is inflammation of the epididymis, the coiled structure behind the testis that stores and transports sperm. Infection commonly ascends from the urethra or bladder through the vas deferens. Inflammation may spread into the testis; involvement of both structures is called epididymo-orchitis. Acute disease usually causes unilateral scrotal pain and swelling that develops gradually over hours to several days. Dysuria, urinary frequency, urethral discharge, fever, and tenderness are possible. The gradual course is a useful clue, but it never makes torsion safe to dismiss. The likely organism depends on more than age: - In sexually active patients younger than about 35, *Chlamydia trachomatis* and *Neisseria gonorrhoeae* are common causes. - In older patients, after urinary instrumentation, or with bladder outlet obstruction such as benign prostatic hyperplasia, enteric Gram-negative organisms—especially *Escherichia coli*—become more likely. - Insertive anal sex can expose a patient to both sexually transmitted and enteric organisms, so treatment must cover both groups when that history is present. Epididymitis is unusual before puberty. A prepubertal child is more likely to have a recent viral illness or an underlying genitourinary...