Epididymo-orchitis (painful, inflamed scrotum)

• Sudden, severe pain, especially before 20, with no urethritis or urinary tract infection: torsion until proven otherwise, immediate urological opinion, without waiting for laboratory results.

Urine tests (midstream)

• Urine microscopy and culture

On first-void urine, collected separately (at least 1 hour after the last void)

• Chlamydia trachomatis and Neisseria gonorrhoeae NAAT (PCR)
• Multiplex PCR for Chlamydia, gonococcus and Mycoplasma genitalium (instead of the previous one if urethritis)if neededSigns of urethritis (discharge, burning): the NABM reserves multiplex PCR with M. genitalium for symptoms of urethritis ^[2]; the European guideline looks for M. genitalium in any orchiepididymitis that looks sexually transmitted ^[3].

Urethral sample (if discharge)

• Urethral sample: direct examination and gonococcal culture with susceptibility testingif neededUrethral discharge or risk of gonococcal infection: gonococcal culture on a urethral sample ^[3,4].

Laboratory tests

• CRPif neededDiagnostic doubt: a raised CRP supports the diagnosis of epididymitis, but must delay neither the surgical opinion nor antibiotics ^[3]. The SPILF 2026 does not provide for CRP in orchiepididymitis and recommends neither inflammatory markers nor blood cultures in outpatients with prostatitis and pyelonephritis ^[5].
• HIV serologyif needednon-French guidelineSexually transmitted cause suspected or confirmed: screen for all other STIs, including blood-borne infections ^[3].
• Syphilis serologyif needednon-French guidelineSexually transmitted cause suspected or confirmed ^[3].
• Hepatitis B serologyif needednon-French guidelineSexually transmitted cause suspected or confirmed: blood-borne infections ^[3].
• Hepatitis C serologyif needednon-French guidelineSexually transmitted cause suspected or confirmed: blood-borne infections ^[3].
• Brucellosis serology (stay in an endemic area)if needednon-French guidelineResidence or travel in an endemic area (Middle East, South Asia, North Africa) ^[3].
• Mumps serology: IgG + IgM (if mumps orchitis suspected: recent parotitis, no vaccination)if needednon-French guidelineThe BASHH (United Kingdom, 2020) proposes IgM and IgG serology or PCR when mumps orchitis is suspected (grade 1C); mumps is notifiable there ^[6]. This orchitis occurs without epididymitis and remains rare in the vaccinated ^[3]. Neither the European guideline nor the SPILF 2026 provides for this test ^[3,5].

Gonococcus: at least 14 days after the end of treatment

• Repeat gonococcus PCRif neededIn France, only if the treatment was not ceftriaxone, if the ceftriaxone MIC exceeds 0.125 mg/L or in case of infection acquired in Asia-Pacific ^[8]; the European guideline proposes a follow-up test in any gonococcal orchiepididymitis ^[3].

Chlamydia or M. genitalium: 4 weeks after the end of treatment

• Repeat PCR (organism initially found)if neededChlamydia: only if symptoms persist ^[9]; M. genitalium: only if symptoms persist more than 3 weeks after the end of treatment ^[10]. The European guideline recommends a routine follow-up test at 4 weeks ^[3].

Reinfection: 3 to 6 months after treatment

• Chlamydia and gonococcus NAAT (PCR) (if Chlamydia or gonococcus confirmed)if neededThe HAS provides for a Chlamydia PCR 3 to 6 months after the treated infection (grade B) ^[9] and, after gonorrhoea, a search for reinfection between 3 and 6 months if risk-taking continues (expert agreement) ^[8]. The CDC and the Australian recommendation retest at 3 months ^[7,11]. This follow-up differs from the test of cure: it aims at a new infection.