Reasoning GP · Algorithm · 1-page summary
Penile discharge
For: people aged 16 and over with penile (urethral) discharge or balanoposthitis in primary care. Not for: under-16s — safeguarding assessment and paediatric sexual-health advice (BASHH children and young people guideline, not adult regimens). Sexual assault → offer SARC referral.
Core rule: discharge from the meatus is an STI until tested — first-void urine NAAT for chlamydia and gonorrhoea, suspected gonorrhoea to GUM for culture and ceftriaxone, and partner notification for every STI.
0Stop — call 999 now — before any history
- Severe genital or perineal pain, swelling, erythema, fever or systemic illness (possible Fournier's gangrene), SGLT2 inhibitor or not → 999 immediate emergency hospital assessment
- Possible torsion — sudden severe scrotal pain, especially under 25, high-riding testis, absent cremasteric reflex → Immediate emergency urology. Do not wait for a scan.
- Acute urinary retention, septic illness or severe disseminated gonococcal infection (DGI) → Emergency hospital; 999 if clinically unstable
- While waiting: never delay transfer or treatment for specimens.
1Triage — where it is managed
| Group | Route |
|---|---|
| Gonorrhoea | Probable or NAAT-positive → same-day GUM: culture, ceftriaxone |
| Possible STI | Stable → GUM 1–5 days (same-day if severe) |
| High risk | MSM, chemsex, assault, PEP within 72 h → same-day GUM / SARC |
| Foreskin | Discharge from under it (balanitis) → GP can manage |
| Under 16 | Safeguarding + specialist sexual-health advice |
2Screen — one row is enough
- Fever + joint pain, tenosynovitis, pustules (DGI) → Same-day hospital/GUM
- Epididymo-orchitis, STI risk → Same-day GUM/emergency; cover gonorrhoea + chlamydia
- Possible resistant gonorrhoea (sex abroad, resistant contact) → Same-day GUM
- Painless penile/oral ulcer + inguinal nodes (syphilis) → serology + Same-day GUM
- Penile mass/ulcer, STI excluded; lesion persisting after STI treatment; persistent foreskin/glans symptoms → consider Suspected cancer pathway (NG12)
- Progressive poor stream (stricture), blood-stained discharge without infection → Urgent urology
3Assess
☐ Sexual history (3 months), PrEP, chemsex ☐ Chaperone, confidentiality, safeguarding ☐ Meatus, foreskin, ulcers, nodes, epididymis, bladder ☐ First-void urine NAAT (not MSU); throat/rectal by exposure ☐ Syphilis, HIV; hepatitis B/C if risk ☐ Glucose/HbA1c if balanitis severe, persistent or recurrent
4Classify — only if the screen is negative
- Gonorrhoea — copious pus, within a week of a new partner → same-day GUM.
- NGU / chlamydia — scant mucoid, 1–3 weeks → NAAT; doxycycline.
- Balanoposthitis — candidal (white, itchy) or bacterial (foul) → swab if significant or recurrent.
- Prostatitis — perineal pain, fever → MSU, antibiotics (NG110). Reactive arthritis → STI screen, GUM.
- Uncertain — NAATs negative, symptoms persist → GUM to confirm urethritis. Pre-ejaculate or dribble → reassure.
5Treat today — doses: NICE, SPC and local formulary
- Gonorrhoea: ceftriaxone 1 g IM via GUM/local pathway; no oral substitute.
- Severe NGU, confirmed chlamydia: doxycycline 100 mg BD 7 days (mild NGU: consider awaiting results). Never azithromycin 1 g stat. Avoid doxycycline in pregnancy.
- Candidal balanitis: clotrimazole 1% BD 7–14 days, or fluconazole 150 mg once if more severe. Bacterial: water/saline; antibiotics only if indicated.
- Every STI: document partner-notification advice, offer GUM; no sex until partners are treated.
6Refer routinely
- Persistent NGU after doxycycline → GUM (M. genitalium testing).
- Phimosis after topical steroid, lichen sclerosus not settling → urology. Red glazed glans not settling → dermatology/GUM.
7Never reassure by
- The look of the discharge — NGU needs objective confirmation.
- Oral antibiotics in surgery for suspected gonorrhoea.
- A normal scan or examination when torsion is possible.
- Repeated azithromycin or doxycycline for persistent NGU.
- Treating the patient without partner notification.
- A penile lesion "still settling" after completed STI treatment.
8Safety-net — say it, then document it
999 “If you get sudden severe pain in the testicle, severe pain or swelling around the penis with fever, a fever with joint pains or a rash, or cannot pass urine, go to A&E straight away — call 999 if very unwell.”
Same day: “Contact us the same day if scrotal pain starts or you are no better 48 hours into treatment. Not settled a week after finishing treatment? Come back.”
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
First-void NAAT sent; syphilis and HIV offered
Suspected gonorrhoea routed to GUM same day
Partner notification and no-sex advice given
Safety-net given; review if not settled
Summary of the full Reasoning GP penile discharge algorithm, which holds the detail, special situations and evidence. Sources: BASHH gonorrhoea (2025), NGU (2026), M. genitalium (2025), chlamydia (2026), balanoposthitis (2026); BHIVA/BASHH PEP; NICE NG12 (updated April 2026), NG110; MHRA; local antimicrobial guidelines. Clinical reference — follow local pathways and check doses: NICE, SPC and local formulary.