The male urinary tract is contiguous with the reproductive organs, so infections arising in the urethra, epididymis, testicle and prostate share common symptoms of dysuria, frequency, and urgency. In healthy young or middle-aged men presenting to the acute care setting, these symptoms are unlikely to be caused by simple cystitis and are usually attributable to sexually transmitted disease or prostatitis.
Urethritis affects about 4 million males in the United States each year. The peak incidence is in males age 20–24. It is most often a sexually transmitted disease, caused by Neisseria gonorrhoeae (gonococcal urethritis) or Chlamydia trachomatis (nongonococcal urethritis, NGU). Other nongonococcal causes include Ureaplasma urealyticum, Mycoplasma hominis, or Trichomonas vaginalis (see Chapter 18, Nonulcerative Sexually Transmitted Diseases). Rare infectious causes of urethritis include lymphogranuloma venereum, herpes genitalis, syphilis, mycobacterium, and adenovirus. Enteric species can cause urethral infection in patients who practice insertive anal intercourse or patients with urethral strictures who develop cystitis.
Male patients with urethritis may present with dysuria, penile discharge, and a history of unprotected sexual contact (Table 20.1). However, up to half of men are asymptomatic and present only because they were referred by a sexual partner who was diagnosed with a sexually transmitted disease (STD). Gonococcal urethritis is more likely to be symptomatic than nongonococcal urethritis.
The differential includes postinstrumentation (traumatic) urethritis, cystitis, pyelonephritis, urethral stricture, and urethral foreign body.