Tests
1st tests to order
Gram stain of urethral secretions
Test
A urethral swab should be sent for Gram stain of urethral secretions in men with symptoms of urethritis (e.g., mucopurulent urethral discharge and/or dysuria).
This test is highly sensitive and specific for documenting urethritis and the presence or absence of gonococcal infection.
Result
≥5 WBC per oil immersion field; presence of intracellular gram-negative diplococci
urine dipstick test
Test
If dipstick testing of the first-void urine shows positive for WBC, it is suggestive of urethritis and lower urinary tract infection.
Result
positive leukocyte esterase test shown as color change on the reagent strip
urine microscopy
Test
First-void urine sample.
Confirms initial urine dipstick test result.
Can be used if dipstick testing not available.
Result
≥10 WBC per high-power field
urine culture
Result
isolate of causative organism
nucleic acid amplification test (NAAT) of urethral secretions or first-void urine for Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium
Test
First-void urine sample for NAAT for C trachomatis, N gonorrhoeae, and M genitalium(where available) is preferred over a urethral sample in asymptomatic men.[28] The International Union Against Sexually Transmitted Infections (IUSTI) recommends testing for M genitalium in men presenting with acute epidiymo-orchitis if they are younger than 50 years.[30] A urethral swab may be collected in men with symptoms of urethritis (e.g., mucopurulent urethral discharge and/or dysuria).[26]
Result
causative organism DNA/RNA detected
culture of urethral secretions
Test
A urethral swab is required for culture for N gonorrhoeae, but culture is less sensitive than nucleic acid amplification testing for gonorrhea and, due to the discomfort associated with a urethral swab, should only be done in symptomatic men (e.g., mucopurulent urethral discharge and/or dysuria). It is the preferred option if antibiotic susceptibility testing is desired.
Test takes several days to yield a result.
Result
positive culture for N gonorrhoeae
Tests to consider
scrotal color duplex ultrasonography
Test
Scrotal color duplex ultrasonography is more accurate for diagnosing acute epididymitis than urinalysis alone, with a sensitivity of 96% and a specificity of 84% to 95%.[7][33]
It is not routinely indicated for patients with suspected epididymitis, but should be done in patients with signs suggestive of abscess formation or possible testicular torsion and infarction.[34]
Result
epididymis is enlarged and hyperemic, with a low-resistance monophasic arterial waveform pattern; good for localizing areas of inflammation
surgical exploration
Test
Standard scrotal exploration may be indicated in cases where testicular torsion cannot be confidently excluded.
Result
edematous epididymis with vascular congestion and evidence of surrounding inflammatory reaction, with no evidence of testicular torsion or other pathology
3 early morning urine samples for acid-fast bacilli staining, culture, and NAAT for Mycobacterium tuberculosis
Test
Indicated when tuberculous epididymitis suspected.[17]
Result
may be positive
HIV test
Test
Indicated in men at risk for, or diagnosed with, an STI, as they are at risk for other STIs.
See HIV infection for more information on testing.
Result
may be positive
syphilis test
Test
Indicated in men at risk for, or diagnosed with, an STI, as they are at risk for other STIs.
See Syphilis infection for more information on testing.
Result
may be positive
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