01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Acute scrotal pain is first a time-to-ischaemia problem and only then an antimicrobial decision. Ask for the exact onset and progression, nausea and previous self-resolving episodes; examine lie, cremasteric response and both testes. Dysuria, urethral discharge or pyuria can coexist with torsion and must not buy time for ultrasound when the clinical picture warrants exploration.
Once torsion is safely addressed, sexual and urinary histories estimate the microbiology more accurately than age. Recent partners, condom use, genital and extragenital exposure and urethritis support chlamydia or gonorrhoea. Instrumentation, obstruction, bacteriuria and prostate disease support an enteric urinary source. Insertive anal sex creates a mixed STI-plus-enteric possibility and changes the empirical combination.
Sampling follows those hypotheses. Use first-catch urine for chlamydia and gonorrhoea NAAT, culture suspected gonorrhoea from the urethra and other exposed sites before ceftriaxone when feasible, and send a midstream urine culture when enteric infection is plausible. A throat or rectal infection may be silent but matters to full sexual-health care and partner management.
Empirical treatment has three distinct lanes. Likely gonorrhoea or chlamydia receives ceftriaxone 1 g intramuscularly once plus doxycycline 100 mg twice daily for 10 to 14 days. Mixed STI and enteric exposure receives ceftriaxone 1 g once plus ofloxacin 200 mg twice daily for 10 days. Enteric-only disease, after gonorrhoea is excluded, receives ofloxacin 200 mg twice daily for 14 days or levofloxacin 500 mg daily for 10 days under current fluoroquinolone restrictions.
Improvement and closure occur on different clocks. Culture review at 48–72 hours can alter therapy; pain and fever should be clearly improving at about three days; a two-week review checks completion, symptoms and partners. Diffuse swelling can settle slowly, but a persistent focal testicular mass demands ultrasound and urology rather than another antibiotic course.
Key points
- Make the torsion decision from onset, nausea, testicular lie and examination before building an infection explanation; high suspicion goes straight to emergency urology without waiting for Doppler.
- Ask what anatomy was exposed, about urethral symptoms and partners, and about instrumentation, obstruction, bacteriuria, prostate symptoms and insertive anal sex; chronological age alone does not select the organism.
- Before treatment when feasible, take first-catch urine NAAT for chlamydia and gonorrhoea, gonococcal culture from relevant sites and midstream urine culture when an enteric source is possible.
- For likely gonorrhoea or chlamydia give ceftriaxone 1 g intramuscularly once plus doxycycline 100 mg orally twice daily for 10 to 14 days.
- For plausible mixed STI and enteric exposure give ceftriaxone 1 g intramuscularly once plus ofloxacin 200 mg twice daily for 10 days, applying current MHRA fluoroquinolone restrictions.
- When gonorrhoea is excluded and an enteric cause is likely, use ofloxacin 200 mg twice daily for 14 days or levofloxacin 500 mg once daily for 10 days only within current restrictions.
- Review cultures at 48–72 hours, clinical improvement at about three days, and adherence and partner completion at two weeks; these are separate checkpoints.
- For chlamydia notify the preceding four weeks; for gonorrhoea notify two weeks or the last partner if longer ago. Test and treat partners for the organism confirmed in the index patient and maintain abstinence until patient and partners complete treatment and follow-up.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Urethral STI ascent
Chlamydia and gonorrhoea can travel proximally after genital exposure, sometimes with only subtle urethritis; exposed-site testing and partner history define the wider episode.
Urinary-source ascent
Susceptible enteric organisms become more likely with bacteriuria, obstruction, prostate disease or instrumentation, so midstream culture and structural review accompany treatment.
Mixed exposure route
Insertive anal sex can expose the urethra to both gonorrhoea and enteric organisms; this clinical category requires combined rather than age-based empirical cover.
Viral or epidemiologically unusual cause
Mumps, tuberculosis, brucellosis and opportunistic infections move up the differential with bilateral disease, parotitis, specific exposure or immune compromise.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Retrograde duct infection
Organisms move from the urethral and ejaculatory pathways through the vas toward the epididymis, producing a local inflammatory focus that can extend into the testis.
- 2Painful tissue expansion
Inflammatory cells and vascular leak enlarge a confined scrotal structure, creating tenderness, erythema, reactive fluid and sometimes systemic fever.
- 3Vascular compromise and suppuration
Marked oedema or uncontrolled infection can reduce perfusion or organise into an abscess, explaining why worsening focal signs require imaging and urological source control.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Abrupt maximal pain, nausea, a high or horizontal lie, absent cremasteric response or earlier episodes that resolved spontaneously make torsion the immediate working risk.
Pain that builds over hours or days with posterior epididymal tenderness, swelling, erythema and sometimes hydrocele supports infection only after torsion has been addressed.
Urethral discharge, dysuria, recent condomless exposure or a diagnosed partner supports chlamydia or gonorrhoea; ask about oral and anal sites because concurrent infection may be silent.
Instrumentation, obstruction, bacteriuria and prostate symptoms point toward urinary organisms, while insertive anal sex can require simultaneous gonococcal and enteric cover.
Pain out of proportion, rapidly spreading erythema, bullae, necrosis, crepitus or toxicity is not routine epididymitis and needs immediate resuscitation, broad intravenous therapy and debridement.
Worsening at three days, persistent fever, focal fluctuation or a remaining intratesticular mass raises abscess, infarction, resistance or malignancy and needs imaging and specialist review.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Time-stamped bilateral genital and abdominal examinationFirst step - Why
- Make the urgent torsion call and identify epididymal localisation, hernia, collection, urinary retention or perineal necrosis.
- Interpretation and limitations
- Record onset, lie and cremasteric response and examine abdomen, groins and perineum. No single sign safely excludes torsion when the overall history is concerning.
- 02
First-catch urine chlamydia and gonorrhoea NAAT - Why
- Detect the common sexually transmitted causes before antibiotics and activate organism-specific partner care.
- Interpretation and limitations
- Use true first-catch rather than a midstream specimen; add rectal and pharyngeal samples according to exposure, symptoms and local practice.
- 03
Gonococcal culture from relevant sites - Why
- Recover susceptibility data before ceftriaxone where this does not delay urgent treatment.
- Interpretation and limitations
- Culture urethral discharge and exposed sites when gonorrhoea is suspected or NAAT is positive; review at 48–72 hours and culture any later positive TOC NAAT.
- 04
Midstream urine culture and urinary assessment - Why
- Test the enteric hypothesis and identify susceptibility, obstruction or instrumentation-related disease.
- Interpretation and limitations
- Interpret culture alongside urinary symptoms, bladder emptying and procedure history; pyuria alone neither proves an enteric cause nor excludes torsion.
- 05
Selective scrotal Doppler ultrasound - Why
- Evaluate an uncertain diagnosis, abscess, infarction or persistent testicular lesion when imaging will change management.
- Interpretation and limitations
- Use after direct urological discussion when torsion is a concern; preserved flow and a radiology queue must not delay indicated exploration.
- 06
Broader STI, blood-borne-virus and exposure testing - Why
- Complete care for the index patient and provide the right testing offer to partners.
- Interpretation and limitations
- Offer HIV and syphilis testing and assess hepatitis testing or vaccination and repeat windows; keep organism-specific lookbacks tied to the final diagnosis.
- 07
Targeted atypical-cause assessment - Why
- Investigate mumps, tuberculosis, brucellosis or opportunistic infection when the phenotype or host context does not fit routine bacterial disease.
- Interpretation and limitations
- Use bilateral disease, parotitis, vaccination, travel, occupational exposure and immune status to select tests and specialist or public-health input.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Spermatic-cord torsion
Abrupt ischaemia may coexist with misleading urinary findings. The onset, nausea and lie drive emergency exploration because delayed certainty can cost the testis.
Torted testicular appendage
Focal upper-pole tenderness or a blue-dot sign may suggest an appendage lesion, but uncertainty about true cord torsion still needs timely surgical assessment.
Incarcerated inguinal hernia
An irreducible groin-to-scrotum swelling with vomiting or obstructive symptoms is a general-surgical emergency rather than an antimicrobial trial.
Testicular tumour or infarction
A discrete intratesticular lesion, especially one persisting after inflammation settles, requires urgent ultrasound and urology even if the initial episode was painful.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01TORSIONSpend no salvage time on infection testsFirst stepOnset, nausea, lie or examination leaves meaningful concern for spermatic-cord torsion.+
- 1Call emergency urology directly, document onset and examination, give analgesia, keep the patient fasted and prepare for exploration.
- 2Do not await urinalysis, NAAT, Doppler access or symptom response when those steps could delay theatre.
- 3An experienced clinician may attempt manual detorsion only when it creates no surgical delay; exploration and fixation are still required.
- 4Continue bilateral examination and communicate uncertainty and any interval change directly to the operating team.
02STITreat the index patient and start organism-specific partner workSexual exposure, urethritis or absent urinary pathology makes gonorrhoea or chlamydia likely after torsion is addressed.+
- 1Take first-catch NAAT and gonococcal cultures from the exposed sites before therapy when feasible, and offer the broader STI and blood-borne-virus screen.
- 2Give ceftriaxone 1 g intramuscularly once plus doxycycline 100 mg orally twice daily for 10 to 14 days.
- 3For chlamydia notify and evaluate partners from four weeks before symptoms; for gonorrhoea use two weeks or the last partner if longer ago, testing and treating for the organism confirmed in the index patient.
- 4Review cultures at 48–72 hours, clinical response at about three days and adherence and partner completion at two weeks; maintain abstinence until patient and partners complete treatment and follow-up.
03MIXED / ENTERICMatch cover to anatomy and urinary evidenceInsertive anal exposure creates mixed risk, or gonorrhoea is excluded and urinary pathology or culture supports an enteric source.+
- 1Send NAAT, gonococcal culture and midstream urine culture and assess obstruction, prostate symptoms and recent instrumentation.
- 2For mixed STI-plus-enteric exposure give ceftriaxone 1 g intramuscularly once plus ofloxacin 200 mg twice daily for 10 days.
- 3For enteric-only disease after gonorrhoea exclusion use ofloxacin 200 mg twice daily for 14 days or levofloxacin 500 mg daily for 10 days, applying current MHRA restrictions and individual risk assessment.
- 4Add rest, scrotal support and analgesia and refer recurrence, obstruction, persistent fever, focal swelling or mass to urology.
04FOLLOW-UPUse each checkpoint for a different decisionEmpirical treatment has begun or pain, fever or swelling is not following the expected course.+
- 1At 48–72 hours act on gonococcal and urine cultures, susceptibility and any discordance with the empirical lane.
- 2At about three days reassess pain, fever and swelling; reconsider torsion, abscess, infarction, resistance and another scrotal diagnosis if improvement is not clear.
- 3At two weeks document adherence, symptom trajectory, partner notification, treatment and abstinence completion.
- 4For gonococcus-positive disease use symptomatic culture at least 72 hours after treatment or asymptomatic NAAT at least two weeks after treatment, culturing any positive NAAT; image and refer any persistent focal mass.
Key medicines and prescribing safety4 treatments · regimens, roles and cautions+
Ceftriaxone plus doxycycline
Give ceftriaxone 1 g intramuscularly once plus doxycycline 100 mg orally twice daily for 10 to 14 days.Check severe beta-lactam allergy, obtain culture when feasible and discuss doxycycline oesophageal irritation, photosensitivity and interacting cations.
Ceftriaxone plus ofloxacin
Give ceftriaxone 1 g intramuscularly once plus ofloxacin 200 mg orally twice daily for 10 days.Apply current MHRA restrictions and review renal function, interactions and individual tendon, neurological, psychiatric, vascular, cardiac and glycaemic risk.
Ofloxacin
Give 200 mg orally twice daily for 14 days only when gonorrhoea is excluded and enteric organisms are likely.Do not use while gonorrhoea remains possible; apply fluoroquinolone restrictions, renal adjustment, interaction checks and serious persistent adverse-effect counselling.
Levofloxacin
Give 500 mg orally once daily for 10 days only when gonorrhoea is excluded and an enteric cause is likely.Use only when recommended alternatives are inappropriate; check renal dosing, interactions and current tendon, neurological, psychiatric, vascular and glycaemic precautions.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Abscess, infarction and tissue loss
A collection or compromised blood supply may require drainage or orchidectomy; persistent fever and focal swelling are the clinical prompts to re-image and escalate.
Impaired fertility
Bilateral inflammation, duct scarring or testicular damage can affect sperm transport or production, with mumps orchitis an important non-bacterial context.
Long-term scrotal pain
Inflammatory and neuropathic pain may remain after organism eradication; a fresh examination and pain pathway are safer than indefinite antimicrobial retreatment.
Ongoing STI transmission and repeat infection
An untreated partner may have no symptoms yet still acquire complications or reinfect the index patient, which is why organism-specific lookbacks and concurrent care matter.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Give an immediate return route for sudden worsening pain, an abnormal testicular position, systemic deterioration or spreading perineal skin change.
- Review gonococcal and urine culture at 48–72 hours and change antimicrobial and partner decisions promptly when susceptibility or organism evidence requires it.
- Reassess clinically at about three days when pain, fever and swelling are not clearly improving; reopen torsion, abscess, infarction, resistance and tumour rather than assuming slow infection response.
- At the separate two-week contact, record course completion, symptom trajectory, the partner-notification outcome and whether abstinence lasted until patient and partners completed treatment and follow-up.
- For gonococcus-positive epididymo-orchitis perform the required test of cure: culture at least 72 hours after treatment when symptomatic, or NAAT at least two weeks after treatment when asymptomatic, with culture of any positive NAAT.
- Use four weeks before symptoms for chlamydia partners and two weeks, or the last partner if longer ago, for gonorrhoea; offer testing and treatment covering the organism confirmed in the index patient.
- Arrange ultrasound and urology assessment for continuing focal swelling or a testicular mass even when pain and fever have improved.
- When mumps is plausible, document parotitis, immunisation and public-health considerations and do not mistake lack of antibacterial response for a need to broaden antibiotics indefinitely.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Urinary findings do not overrule the clock
Pyuria and dysuria can coexist with torsion; abrupt onset and abnormal lie still require immediate urological discussion.
Sexual practice chooses the empirical lane
Insertive anal exposure can create simultaneous gonococcal and enteric probability, while age by itself cannot reliably separate STI from urinary pathogens.
First-catch and midstream urine answer different questions
First-catch NAAT targets urethral chlamydia and gonorrhoea; midstream culture addresses an enteric urinary source. Substituting one for the other loses information.
Follow-up contains three clocks
Cultures at 48–72 hours, clinical response near three days and completion and partner review at two weeks each answer a distinct safety question.
Swelling can lag behind cure
Diffuse inflammatory enlargement may recede slowly, while a persistent discrete mass needs ultrasound because tumour, infarction or abscess cannot be inferred from pain improvement.
Fluoroquinolone choice carries a threshold
Ofloxacin or levofloxacin belongs only in the specified mixed or enteric pathway after organism reasoning and current MHRA restriction checks.
Partners are part of recurrence prevention
Symptoms do not determine whether a partner carries chlamydia or gonorrhoea; confidential notification, testing, treatment and shared abstinence completion close the transmission loop.
11Common pitfallsFrequent interpretation and management errors.
- 01
Do not let dysuria, pyuria, urethral discharge or a positive STI history postpone emergency torsion assessment.
- 02
Do not order Doppler as a holding step when the clinical probability already warrants exploration.
- 03
Do not select an STI or enteric regimen from age alone; use exposed anatomy, urethritis, instrumentation, obstruction and cultures.
- 04
Do not use ceftriaxone alone while chlamydia remains possible or an enteric-only fluoroquinolone while gonorrhoea remains possible.
- 05
Do not collapse the 48–72-hour culture check, about-three-day clinical review and two-week compliance and partner review into one vague follow-up.
- 06
Do not repeat antibiotics for a persistent focal testicular mass without ultrasound and urology assessment.