Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (250 page)

   Mycobacteria are shed intermittently, so four to six first-morning samples should be submitted for mycobacterial culture. Mycobacterial culture of samples from other potentially infected sites is also recommended, as well as skin (or comparable) testing for TB. False-positive AFB smears may be seen due to nonpathogenic mycobacteria.

   Urinalysis typically shows WBCs; WBC casts are unusual. Some degree of hematuria is demonstrated in most patients.

   Renal function tests are usually normal; heavy proteinuria is uncommon.

EPIDIDYMITIS

   Definition

   Epididymitis is inflammation of the epididymis. The epididymis stores sperm cells received from the tubules of the rete testis, facilitates their maturation, and ultimately delivers them to the vas deferens.

   Who Should Be Suspected?

   Epididymitis most commonly has an infectious etiology, presenting as either an acute condition (<6 weeks) or, more typically, chronic (≥6 weeks). The acute presentation is characterized by severe scrotal swelling and exquisite pain, often accompanied by high fever, rigors, and irritative voiding symptoms (frequency, urgency, and dysuria). The chronic presentation includes scrotal pain but usually lacks irritative voiding symptoms. Asymptomatic urethritis often accompanies epididymitis originating with sexually transmitted agents.

   Noninfectious epididymitis (precipitated by, e.g., trauma, autoimmune disease, or vasculitis) generally presents as a chronic condition, with less pain and swelling (less epididymal inflammation).

   The differential diagnosis of epididymitis should consider a range of other sources of scrotal pain and swelling, e.g., testicular torsion, Fournier gangrene (necrotizing fasciitis of the perineum with mixed aerobic/ anaerobic bacteria), trauma/surgery, testicular cancer, inguinal hernia, Henoch-Schönlein purpura (IgA vasculitis), or epididymo-orchitis (e.g., post-mumps).

   Laboratory Findings (Infectious Epididymitis)

   A urinalysis and urine culture should be performed on all patients suspected of urethritis. A urethral swab should be obtained in patients with urethral discharge and sent for culture and nucleic acid amplification testing for chlamydia and gonorrhea.

   In sexually active men under age 35,
Chlamydia trachomatis
and
Neisseria gonorrhoeae
are the most frequent causative agents. Combined infections by both agents are more frequently found than infections by
N. gonorrhoeae
alone.