Dysuria in a young man is categorically different from dysuria in a woman — UTI in men under 50 is uncommon (the male urethra is approximately 20 cm vs 4 cm in women, making ascending bacterial colonisation much less likely), and when it does occur, it should prompt investigation for a structural cause (urethral stricture, BPH in older men, prostatitis, reflux) or an STI. The most common error in primary care is prescribing nitrofurantoin or trimethoprim for 'UTI' in a sexually active young man without performing an STI screen — this misses gonorrhoea or Chlamydia, delays appropriate STI treatment, misses partner notification, and may provide partial cover for GC that selects for resistance. The rule: any sexually active man under 50 with dysuria should have an STI screen (first-void urine for Chlamydia/GC NAAT + urethral swab if discharge present) before antibiotic treatment. UTI in men requires 7-day treatment (not 3 days) because of the risk of subclinical prostatic involvement.

The differentiation between UTI and urethritis is a clinically important distinction that determines whether the patient needs antibiotics, STI screening, or both. The key clinical discriminators: UTI produces a symptom triad of dysuria + frequency + urgency (the bladder is inflamed and contracting against urine), while urethritis produces predominantly dysuria (the urethra is inflamed) without significant frequency/urgency. Urethral discharge is pathognomonic of urethritis and essentially excludes simple UTI. The urine dipstick is unhelpful in differentiating the two conditions — leucocytes are positive in both UTI (inflammatory cells in bladder urine) and urethritis (inflammatory cells in urethra contaminate the urine sample). The most reliable differentiator is MSU culture: UTI produces bacterial growth >10⁵ CFU/ml; urethritis produces a negative culture (bacteria are in the urethra, not the bladder). A patient with dysuria and a positive dipstick but a negative MSU culture should be screened for Chlamydia/GC.

The nitrofurantoin and MSU before prescribing principle has undergone a nuanced update in NICE NG112 — for uncomplicated cystitis in otherwise healthy non-pregnant women under 65 with classic symptoms (dysuria + frequency + urgency) and a positive dipstick (leucocytes + nitrites), MSU culture before prescribing is NOT required. The diagnostic accuracy of the clinical presentation + dipstick combination is sufficient to treat empirically. However, the 'test and treat' or 'dipstick + culture' approach remains appropriate for: men, pregnant women, children, patients with recurrent UTI (to identify organisms and sensitivities), immunocompromised patients, those with atypical symptoms, and elderly patients in whom the diagnosis of UTI is more uncertain (atypical presentations are common in elderly — confusion or falls without classic urinary symptoms can represent UTI in this group, but positive dipstick in elderly should be interpreted with caution given the high prevalence of asymptomatic bacteriuria). The MHRA and NICE 2023 guidance on trimethoprim notes that trimethoprim should not be prescribed empirically without considering local resistance data — trimethoprim resistance in E. coli has reached 25–30% nationally, making it an unreliable empirical choice in many areas.

Interstitial cystitis / bladder pain syndrome (IC/BPS) is a frequently missed diagnosis that presents as chronic dysuria — it affects approximately 1 in 100 women and is characterised by chronic (≥6 months) pelvic pain, pressure, or discomfort perceived to be related to the bladder, with at least one urinary symptom (urgency or frequency), in the absence of infection or other identifiable cause. The typical patient has had multiple courses of antibiotics for 'recurrent UTI' but MSU cultures are consistently negative or grow only low-count organisms. Key features: suprapubic pain that worsens as the bladder fills and relieves with urination, dyspareunia, nocturia, and frequency. Diagnosis requires exclusion of UTI (negative cultures), cystoscopy (to exclude malignancy, and to look for Hunner's lesions — present in ~10% of IC), and urodynamics. Treatment: pelvic floor physiotherapy + oral pentosan polysulfate + amitriptyline + bladder instillation (specialist). GPs should suspect IC in any patient with chronic dysuria and consistently negative cultures, especially if antibiotic courses are being repeatedly prescribed without effect.

The NICE NG12 2WW haematuria referral rule is one of the most important cancer safety-netting rules in primary care — it is frequently violated by attributing haematuria to UTI and not following up after treatment. The correct approach when a patient presents with dysuria AND macroscopic haematuria: (1) check for UTI and treat if confirmed; (2) arrange 2WW urology referral simultaneously. Do not wait to see if the haematuria resolves with antibiotic treatment — bladder cancer commonly co-presents with UTI, and treating the infection does not treat the cancer. A patient who had haematuria with a 'UTI' that appeared to resolve should still be referred if they had not had a 2WW assessment. GPs should have a system for checking that 2WW referrals for haematuria are not inadvertently dropped when haematuria 'resolves' with antibiotics.

Aciclovir for first-episode genital herpes has several important clinical nuances that GPs should know: (1) it must be started within 5 days of lesion onset to be effective (after this, viral replication has largely ceased and antiviral treatment has minimal benefit on the current episode); (2) the antiviral reduces the duration and severity of the episode but does not affect the establishment of latency in the sacral ganglia (herpes will likely recur); (3) patients should be counselled that they will have lifelong HSV infection that can reactivate; (4) suppressive therapy (aciclovir 400 mg BD or valaciclovir 500 mg OD long-term) is available for patients with frequent recurrences (≥6/year) and reduces recurrence frequency by approximately 80% — this is a GUM clinic discussion; (5) asymptomatic shedding (when the virus is infectious without any visible lesions) occurs on approximately 10–15% of days and is responsible for most HSV transmission between sexual partners. GUM referral after the first episode is important to ensure appropriate counselling, partner testing, and long-term management planning.

The 28-day antibiotic course for acute bacterial prostatitis is one of the most consistently shortened treatments in primary care — the full 28-day course is essential because antibiotic penetration into the prostate is poor (blood-prostate barrier), and shorter courses (7–14 days) result in bacterial persistence in the prostate, causing relapse and progression to chronic bacterial prostatitis. Ciprofloxacin has the best prostate tissue penetration of available oral antibiotics (lipophilic — crosses the blood-prostate barrier effectively). The clinical monitoring during the 28-day course: if the patient is not significantly improved at 7 days, reconsider the diagnosis (prostatic abscess — requires USS/MRI + drainage) or antibiotic choice (culture sensitivity — if organism resistant to ciprofloxacin, switch based on culture). Transrectal ultrasonography (TRUS) is indicated if there is no improvement at 1 week of appropriate antibiotics — a prostatic abscess requires surgical drainage (transperineal or transrectal).

The genital herpes disclosure dilemma is one of the most sensitive psychosocial aspects of managing first-episode HSV — patients often struggle with the question of when and how to inform sexual partners, and some experience significant shame, anxiety about future relationships, and fear of rejection. Proactive, empathetic GP counselling at the first HSV consultation significantly improves patient outcomes. Key messages: HSV is extremely common (approximately 67% of the world population has HSV-1, approximately 11% has HSV-2); most people with genital herpes do not know they have it (majority of acquisition is from asymptomatic shedding by a partner who did not know they were infected); having genital herpes does not mean you or your partner has been unfaithful (the infection can be dormant for years before first presentation); the infection is manageable with suppressive treatment; and long-term relationships with HSV-positive partners are possible with appropriate precautions. GUM referral provides specialist counselling support beyond what can be delivered in a primary care consultation.

The test of cure for pyelonephritis is a NICE and SIGN recommendation that is frequently omitted in primary care — unlike uncomplicated cystitis (where a test of cure is not routinely needed), pyelonephritis involves the renal parenchyma and requires confirmation of bacteriological clearance after treatment. A repeat MSU at 7 days post-completion of treatment confirms bacteriological cure. If the culture is still positive: MSU sensitivity-guided antibiotic change + urology referral (structural cause maintaining infection). Post-pyelonephritis renal USS is also recommended to exclude: hydronephrosis (obstruction), renal abscess, renal stone (cause of pyelonephritis), and anatomical abnormality. A normal renal USS after the first episode of pyelonephritis provides reassurance and documents baseline; an abnormal USS guides urology management.