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← Infectious diseases, microbiology and sexual health indexChapter sections
OverviewAetiologyPathophysiologyClinical features and red flagsInvestigationsDifferential diagnosisManagementComplicationsMonitoring and follow-upSpecial situationsCommon pitfallsQuestionsSources
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Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.

Prostatitis

Infectious diseases, microbiology and sexual health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Prostatic sepsis, retention or abscess

Hypotension, confusion, severe systemic illness, inability to pass urine or deterioration despite therapy suggests sepsis, obstructed drainage or prostatic abscess.

Action: Use ABCDE, obtain urine and blood cultures without delaying treatment, start locally recommended intravenous therapy, avoid prostatic massage and involve urology urgently for drainage and retention management.

Overview

Recognise acute bacterial prostatitis, distinguish sepsis and retention, obtain useful cultures and prescribe prostate-penetrating treatment with an explicit fourteen-day review.

Acute bacterial prostatitis is abrupt bacterial infection of prostate tissue, usually caused by enteric Gram-negative organisms entering through the urethra or refluxing infected urine into prostatic ducts.

Prostate penetration matters. Bladder-only agents such as nitrofurantoin do not achieve therapeutic tissue concentrations and are unsuitable even when a urine isolate appears susceptible.

Fluoroquinolones penetrate prostate tissue but carry strict safety restrictions. Use them only when other commonly recommended antibiotics are inappropriate after individual adverse-effect and interaction review.

Acute bacterial prostatitis is distinct from chronic bacterial prostatitis and chronic pelvic pain syndrome. Recurrent or prolonged symptoms need culture, anatomical and pain assessment rather than automatic repetition of an acute regimen.

Key points

  • Acute bacterial prostatitis causes fever, pelvic or perineal pain and urinary symptoms, sometimes with retention or sepsis.
  • A gentle rectal examination may support diagnosis, but

Aetiology

01

Ascending enteric organisms

Escherichia coli and other Enterobacterales enter through the urethra or reflux infected urine into prostatic ducts, causing most acute cases.

02

Instrumentation and obstruction

Biopsy, catheterisation, cystoscopy, urinary retention and prostatic enlargement facilitate bacterial entry and increase healthcare-associated resistance risk.

03

Sexually transmitted pathogens

Gonorrhoea and chlamydia are less common causes but should be considered with urethritis, exposure history or epididymal symptoms.

Pathophysiology

  1. 1
    Ductal bacterial invasion

    Organisms enter prostatic ducts, replicate within glandular tissue and trigger intense neutrophilic inflammation, oedema and pelvic pain.

  2. 2
    Outlet obstruction

    Inflammatory swelling compresses the prostatic urethra, causing weak flow, residual urine and sometimes complete painful retention.

  3. 3
    Tissue penetration barrier

    Drug ionisation, protein binding and lipid solubility determine prostate exposure, making some bladder-active antibiotics clinically inadequate.

  4. 4
    Abscess formation

    Persistent focal suppuration can become encapsulated, preventing cure with antibiotics alone and requiring image-guided or operative drainage.

Clinical features and red flags

Acute systemic urinary syndromeRed flag

Fever, rigors, malaise, dysuria, frequency and urgency with perineal, rectal, penile or low-back pain supports acute bacterial prostatitis.

Tender prostate

Gentle rectal examination may find a tender boggy or swollen prostate, but absence does not exclude infection and forceful massage is unsafe.

Urinary retentionRed flag

Weak stream, painful inability to void and palpable bladder suggests oedema-related outlet obstruction requiring prompt urological assessment.

Prostatic abscessRed flag

Persistent fever, bacteraemia or focal pelvic pain despite active therapy raises suspicion for a collection requiring imaging and drainage.

Red flags requiring action

  • Hypotension, tachypnoea, confusion or mottling indicates sepsis requiring emergency escalation.
  • Acute inability to pass urine with a painful bladder requires urgent urological drainage planning.
  • Persistent fever after 36 to 48 hours of active therapy raises concern for prostatic abscess.
  • Recent biopsy, catheterisation or resistant isolate increases healthcare-associated and resistant organism risk.
  • Severe pelvic pain with immunosuppression or diabetes lowers the threshold for admission and imaging.

Investigations

  1. 01
    Midstream urine culture and susceptibilityFirst step
    Why
    Confirm the organism and guide a prostate-penetrating regimen before antibiotics.
    Interpretation and limitations
    Enterobacterales predominate, but recent instrumentation changes resistance risk. A negative result after treatment does not exclude the clinical diagnosis.
  2. 02
    Blood cultures
    Why
    Identify bacteraemia when fever, rigors, sepsis or admission is present.
    Interpretation and limitations
    Obtain before antimicrobials when safe; persistent positive cultures suggest inadequate activity, abscess or another bloodstream source.
  3. 03
    Full blood count, renal profile, CRP and lactate
    Why
    Assess severity, organ dysfunction and safe antimicrobial dosing.
    Interpretation and limitations
    Inflammatory markers support but do not establish diagnosis; creatinine and potassium guide treatment and retention-related renal injury assessment.
  4. 04
    Bladder scan
    Why
    Quantify urinary retention when voiding is difficult or urine output falls.
    Interpretation and limitations
    A significant residual with infection requires urgent urological discussion; repeated traumatic urethral catheter attempts can worsen injury and bacteraemia.

Differential diagnosis

01

Lower urinary infection

Cystitis produces dysuria and frequency without prominent fever, perineal pain, prostate tenderness or significant systemic illness.

02

Epididymo-orchitis or urethritis

Scrotal pain, epididymal swelling or urethral discharge suggests a sexual-health or enteric genital infection requiring targeted testing.

03

Chronic pelvic pain syndrome

Pelvic pain lasting months with negative cultures and variable urinary or sexual symptoms is not managed as prolonged acute infection.

04

Prostate or bladder malignancy

Persistent haematuria, weight loss, abnormal prostate findings or recurrent sterile urinary symptoms requires prompt urological cancer assessment.

Additional chapter-specific clues

Sexual-health alternative

Urethral discharge, new sexual exposure, epididymal pain or proctitis features should prompt STI testing alongside bacterial urine culture.

Management

01STABLETreat orally with reviewFirst stepAcute bacterial prostatitis is likely, oral absorption is reliable and there is no sepsis, retention or abscess concern.+
  1. 1Obtain culture and assess renal function, allergy, previous isolates, recent antibiotics, interactions and individual fluoroquinolone adverse-effect risk.
  2. 2Choose a prostate-penetrating NICE regimen: ciprofloxacin or ofloxacin only when appropriate, or trimethoprim when a fluoroquinolone is unsuitable and resistance risk permits.
  3. 3Provide analgesia, hydration advice, serious adverse-effect counselling and urgent return criteria for retention or systemic deterioration.
  4. 4Review at 14 days using symptoms, examination and culture; stop or continue for a further 14 days according to that assessment.
02ADMIT

Complications

01

Prostatic abscess

Ongoing bacterial suppuration produces persistent fever, pain and bacteraemia despite active treatment and often requires drainage.

02

Urinary retention

Acute inflammatory oedema obstructs the urethra, causing painful bladder distension, renal injury and urgent drainage need.

03

Bacteraemia and sepsis

A vascular inflamed gland can seed the bloodstream spontaneously or after manipulation, leading to organ dysfunction and shock.

04

Chronic symptoms and recurrence

Inadequate activity, resistant organisms or structural disease can lead to recurrent infection, chronic pain and voiding dysfunction.

Monitoring and follow-up

  • Advise urgent review for worsening systemic illness, inability to pass urine, vomiting or new confusion at any time.
  • Review response and culture within 48 hours; lack of progress requires admission, imaging and abscess assessment.
  • At 14 days document whether treatment stops or continues for another 14 days and why.
  • Check renal function and potassium when trimethoprim, retention or acute kidney injury makes abnormalities plausible.
  • Refer persistent pelvic pain, recurrent infection, haematuria or voiding dysfunction to urology rather than repeating empirical antibiotics.
  • Confirm pain control, urinary flow and a clear fourteen-day review appointment before an outpatient leaves care.
  • When bacteraemia is present, confirm clearance and reconsider an endovascular or metastatic focus if positive blood cultures persist despite active therapy.

Special situations

Four weeks is not automatic

NICE structures treatment as 14 days followed by review; only ongoing clinical need supports a further 14 days.

Massage can seed blood

Forceful prostatic massage during acute infection can worsen pain and provoke bacteraemia and should not be performed.

Bladder agents miss tissue

Nitrofurantoin may test active in urine yet does not reach dependable prostate concentrations for acute prostatitis.

Retention needs technique

Acute retention requires urological input because inflamed obstructed anatomy and repeated instrumentation can cause trauma and bacteraemia.

Persistent fever means image

Failure to defervesce on active therapy should trigger evaluation for prostatic abscess, resistance or another infection source.

PSA is misleading acutely

Prostate-specific antigen can rise during acute inflammation and should not be used to diagnose infection or trigger premature cancer interpretation during the episode.

Common pitfalls

  1. 01

    Do not use nitrofurantoin for acute bacterial prostatitis despite a susceptible urine report.

  2. 02

    Do not perform vigorous prostate massage to obtain secretions during acute infection.

  3. 03

    Do not prescribe a fluoroquinolone without applying current restrictions and explaining potentially persistent adverse effects.

  4. 04

    Do not leave acute urinary retention for routine review; arrange prompt urological drainage assessment.

  5. 05

    Do not continue long courses without reviewing culture, anatomical complications and alternative chronic pelvic pain syndromes.

Practice

Two practice questions

Your practice draft is saved in this browser.

Question 1 of 2
0 correct
Infectious diseases, microbiology and sexual healthOriginal SBA

Initial oral regimen review

A stable adult with culture-supported acute bacterial prostatitis can take oral medicine and has no retention. A fluoroquinolone is appropriate after safety review. Which NICE regimen is correct?

Choose one answer, then submit
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Sources and review status3 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NICE NG110 Prostatitis acute antimicrobial prescribing
  • MHRA Fluoroquinolone antibiotics prescribing restrictions
  • NHS Prostatitis information

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
do not
massage an acutely inflamed prostate.
  • Send a midstream urine culture before antibiotics and take blood cultures when febrile or systemically unwell.
  • Hospital referral is indicated for sepsis, retention, inability to take oral treatment or failure to improve within 48 hours.
  • NICE oral options are ciprofloxacin 500 mg twice daily or ofloxacin 200 mg twice daily for 14 days then review, only when fluoroquinolone use is appropriate.
  • When a fluoroquinolone is inappropriate, trimethoprim 200 mg twice daily for 14 days then review is an alternative guided by resistance risk.
  • At 14 days, stop or continue for a further 14 days according to symptoms, examination and culture rather than prescribing four weeks automatically.
  • Image and seek urology input when fever or pain persists despite active treatment because an abscess may need drainage.
  • 05
    Transrectal ultrasound, CT or MRI
    Why
    Detect prostatic abscess or another pelvic focus when response is inadequate.
    Interpretation and limitations
    Imaging is not routine in a rapidly improving case; arrange it when fever persists after 36 to 48 hours or abscess risk is high.
  • 06
    STI nucleic acid testing
    Why
    Assess gonorrhoea and chlamydia when urethritis or exposure makes them plausible.
    Interpretation and limitations
    Use correct first-catch urine or swab technique and manage confirmed infection and partners through current sexual-health guidance.
    • Manage sepsis or oral failure
    The patient is severely unwell, cannot take oral medicines, has retention or does not improve within 48 hours.
    +
    1. 1Use ABCDE, obtain urine and blood cultures, start local intravenous therapy promptly and monitor urine output and renal function.
    2. 2Discuss acute retention with urology; choose the safest drainage route and avoid repeated traumatic urethral instrumentation.
    3. 3Image for abscess when fever or pain persists and arrange drainage if a collection is found.
    4. 4Review intravenous treatment by 48 hours and step down only when physiology, oral intake and susceptibility support a safe oral plan.
    03AVOID HARMRespect prostate and drug safetyExamination, catheterisation or fluoroquinolone prescribing is being considered.+
    1. 1Do not perform prostatic massage in acute infection because pressure can worsen pain and precipitate bacteraemia.
    2. 2Use gentle examination only when the result assists diagnosis and stop if pain is severe.
    3. 3Apply current MHRA fluoroquinolone restrictions and review tendon, neurological, psychiatric, vascular, cardiac, renal and interaction risk.
    4. 4Tell the patient to stop a fluoroquinolone and seek advice for tendon pain, neuropathy, severe neuropsychiatric symptoms or other serious toxicity.
    04REASSESSInvestigate delayed responseFever, pain, bacteraemia or voiding difficulty persists after 36 to 48 hours of active treatment.+
    1. 1Repeat clinical and bladder assessment and verify culture susceptibility, absorption, adherence and antimicrobial dosing.
    2. 2Arrange prostate imaging and urology review for possible abscess or ongoing obstruction.
    3. 3Reconsider epididymo-orchitis, urethritis, colorectal disease and non-infective pelvic pain when the pattern no longer fits.
    4. 4Document source-control, treatment-duration and safety-net decisions before discharge.
    Key medicines and prescribing safety4 treatments · regimens, roles and cautions+
    NICE first-choice oral prostate-penetrating therapy only when a fluoroquinolone is clinically appropriate.

    Ciprofloxacin

    Give 500 mg orally twice daily for 14 days, then review and stop or continue for a further 14 days according to response.

    Follow MHRA restrictions; assess renal function, tendon, neurological, psychiatric, aortic, cardiac and glycaemic risk and interactions, and avoid in pregnancy.

    Alternative NICE first-choice fluoroquinolone with prostate penetration when its use remains appropriate.

    Ofloxacin

    Give 200 mg orally twice daily for 14 days, then review and stop or continue for a further 14 days according to response.

    Apply fluoroquinolone restrictions, dose adjustment and serious adverse-effect counselling; review QT prolongation, interacting medicines and previous resistant organisms.

    NICE alternative when a fluoroquinolone is inappropriate and likely susceptibility supports treatment.

    Trimethoprim

    Give 200 mg orally twice daily for 14 days, then review and stop or continue for a further 14 days as clinically indicated.

    Check renal function, potassium, folate status, resistance risk and interactions with methotrexate, warfarin, ACE inhibitors and spironolactone.

    Provides a specialist-selected alternative prostate-penetrating option for culture-informed acute prostatitis.

    Levofloxacin second-choice

    Give 500 mg orally once daily for 14 days only after specialist advice when first-choice treatment is unsuitable or ineffective.

    Use only under fluoroquinolone restrictions; adjust for renal impairment and review tendon, neurological, psychiatric, vascular, QT and glycaemic risks.