12 - Urethral Discharge

Authors: Macfarlane, Michael T.

Title: Urology, 4th Edition

Copyright 2006 Lippincott Williams & Wilkins

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Chapter 12

Urethral Discharge

Presentation

Generally a young, sexually active male patient complains of urethral discharge (watery to purulent), with or without urethral burning or itching, and burning on urination. Urinary frequency and urgency are typically absent.

History

Ask about recent sexual contacts, history of venereal disease, and first onset of symptoms.

Differential Diagnosis

Gonococcal Urethritis

Gonococcal urethritis (GCU) has a short incubation of 1 to 5 days and generally produces a thick, purulent, yellowish discharge. The causative organism is Neisseria gonorrhoeae. Up to 30% of male patients with GCU also will be infected with Chlamydia trachomatis.

Nongonococcal Urethritis

Nongonococcal urethritis (NGU) has a long incubation of 5 to 21 days and generally produces a watery-to-mucoid, whitish discharge. The most common causative organisms include C. trachomatis, Ureaplasma urealyticum, Trichomonas vaginalis, and Mycoplasma.

Workup

Examination

Examination should be performed at least 1 hour after last voiding and preferably 4 hours after voiding. (This is often a problem

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in the clinic setting because patients are generally instructed to give a urine specimen before seeing the doctor.) Notice whether the discharge is watery or thick, mucoid or purulent, and whitish or yellowish. Obtain a urethral specimen from within the urethra by using a calcium alginate (Calgiswab) urethrogenital swab for culture. (A drop of discharge is unacceptable.) Pharyngeal and rectal swabs also should be obtained if the history suggests exposure. Perform a routine genitourinary examination.

Culture Urethral Specimen

Culture on modified Thayer-Martin medium and New York City medium for N. gonorrhoeae. Suspicion of C. trachomatis requires culture on special media.

Gram's Stain of a Urethral Swab

The traditional Gram stain of a urethral swab specimen is generally not performed today, because modern antibiotic therapy will be directed against both GCU and NGU simultaneously. The presence of urethritis is confirmed by counting more than four polymorphonuclear leukocytes per oil immersion field ( 1,000) from a Gram stain of a urethral swab. Demonstration of intracellular gram-negative diplococci within polymorphonuclear leukocytes is strong evidence of gonorrhea (99% specific and 95% sensitive in trained hands). No gram-negative cocci is strong evidence for NGU. Only extracellular gram-negative cocci are considered equivocal and nondiagnostic.

Treatment

Treatment should not await culture results because antibiotic therapy should cover both GCU and NGU. Azithromycin 2 g PO single dose is generally effective against both GCU and NGU. Ceftriaxone 125 mg IM once or cefixime 400 mg PO once or ciprofloxacin 500 mg PO or levofloxacin 250 mg single dose will effectively treat most GCU, although increasing resistance to fluoroquinolones has been noted in California, Hawaii, and Asia. The addition of doxycycline 100 mg PO bid 7 days will be effective against most NGU organisms. Every effort should be made to treat the patient's sexual partner (see Chapter 18).