Fournier's gangrene is one of the most rapidly fatal infections in clinical medicine — it is a synergistic polymicrobial necrotising fasciitis (predominantly anaerobes + gram-negative aerobes working together to destroy fascial planes) involving the genitalia, perineum, and perianal region. Mortality remains approximately 20-40% despite modern treatment. The critical diagnostic challenge: the external appearance in early Fournier's is deceptively mild — the overlying skin initially shows only erythema, which rapidly progresses to a dark, necrotic, or dusky colour. The most important clinical sign: pain DISPROPORTIONATE to the visible skin changes — the infection spreads rapidly along fascial planes deep to the dermis, destroying subcutaneous tissue and fascia while the overlying skin appears relatively intact. Crepitus on palpation (gas in the soft tissues from anaerobic metabolism) is a late and pathognomonic sign but should not be awaited before acting. Any man with genital pain + swelling + fever + systemic illness who appears out of proportion to the visible skin changes should be considered to have Fournier's gangrene until proved otherwise — 999.

Lichen sclerosus of the penis (penile LS, also called BXO — balanitis xerotica obliterans) is the most important benign penile condition for GPs to diagnose correctly because: (1) it is frequently misdiagnosed as recurrent candidal balanitis and treated empirically with antifungals for months to years; (2) inadequately treated penile LS progresses to phimosis, meatal stenosis, and penile SCC (approximately 2-5% malignant transformation rate); and (3) first-line treatment with clobetasol 0.05% ointment is highly effective if started early. The clinical appearance: white, atrophic, shiny plaques on the glans, inner foreskin, and prepuce — often with a white 'ring' at the preputial orifice (causing pathological phimosis). The key diagnostic test: biopsy (if diagnosis is uncertain or if the lesion is not responding to clobetasol). Treatment: clobetasol 0.05% ointment OD applied to affected areas for 3 months (induction), then maintenance. Annual examination for malignant transformation: any new ulcer, induration, or non-healing lesion on background of LS should be referred 2WW.

The syphilis chancre on the penis is the most important STI diagnosis not to miss at a 'balanitis' or 'penile ulcer' consultation — primary syphilis presents as a single, painless, well-defined ulcer (chancre) with a clean base and indurated edges, typically on the glans or the inner foreskin. The ulcer is painless (unlike HSV which is extremely painful), has a hardened base (unlike the soft, shallow base of aphthous ulcers), and is accompanied by unilateral or bilateral non-tender inguinal lymphadenopathy (rubber-like, non-fluctuant nodes). Without treatment, the primary chancre heals spontaneously in 3-6 weeks — but syphilis progresses to secondary (systemic) and tertiary (cardiovascular, neurological) syphilis if untreated. The incidence of syphilis in the UK has increased dramatically since 2010, with approximately 8,000 cases reported per year in England (2023 PHE data). Any penile ulcer in a sexually active man must have syphilis serology requested (TPHA + RPR). Treat primary syphilis: benzathine penicillin G 2.4 MU IM single dose (or doxycycline 100 mg BD x 14 days if penicillin-allergic). Partner notification via GUM clinic.

Peyronie's disease intralesional collagenase clostridium histolyticum (Xiapex) was approved by NICE (2016) as the first non-surgical treatment for Peyronie's disease — it is injected directly into the fibrous plaque under local anaesthesia, breaking down the collagen fibres that form the plaque. The treatment protocol: 2 injections per cycle (24-72 hours apart), up to 4 cycles at 6-week intervals. A penile modelling procedure (gentle penile bending in the opposite direction to the curvature) is performed 24-72 hours after each injection and at home for 6 weeks. Clinical trial data (IMPRESS I and II): approximately 35% reduction in penile curvature compared to 18% for placebo. Patient eligibility for Xiapex: stable Peyronie's (≥3 months), curvature 30-90°, palpable plaque. Contraindications: Peyronie's with a plaque involving the urethra, Dupuytren's contracture of hands (cross-reactive antibodies to collagenase). GPs should refer appropriate Peyronie's patients to urology when the active phase has stabilised.

The circumcision decision for recurrent balanitis or phimosis in adults requires a nuanced approach in primary care — not all adult men with phimosis or balanitis require circumcision, and conservative management should be attempted first in most cases. For pathological phimosis (lichen sclerosus/BXO): clobetasol 0.05% ointment OD x 3 months is the first-line treatment and achieves resolution of the phimosis in approximately 70-80% of cases (allowing foreskin retraction without surgery). For recurrent candidal or bacterial balanitis: treat the underlying cause (diabetes — optimise glycaemic control; phimosis — clobetasol; poor hygiene — education) before recommending circumcision. For true pathological phimosis resistant to topical steroid treatment, or for recurrent BXO with severe scarring, or recurrent paraphimosis: circumcision is appropriate and should be referred to urology. NHS circumcision for adults: available for pathological phimosis and BXO/LS but not for routine balanitis in most CCGs.

The penile traction device (PTD) for Peyronie's disease has an increasingly strong evidence base that GPs should be aware of — mechanical penile traction (using a validated device such as RestoreX or Andropenis that applies gentle stretch to the non-affected side of the penis) stimulates mechanotransduction in the fibrous plaque, promoting collagen remodelling and reducing curvature. A systematic review and several RCTs demonstrate that PTD used for at least 3 hours per day (or 2 hours per day for RestoreX specifically) over 3-6 months reduces penile curvature by an average of 10-20 degrees and may improve penile length lost during Peyronie's development. The devices are safe, non-invasive, and do not preclude subsequent Xiapex or surgical treatment. GPs managing Peyronie's in the active phase can recommend PTD while waiting for the stable phase (minimum 6-12 months of stable curvature before considering Xiapex or surgery). The devices are available commercially without prescription, and patient education on correct usage (no erection required — applied to flaccid penis) is important for compliance.

The corporal aspiration technique for ischaemic priapism is a procedure that GPs with appropriate training and equipment can perform as a temporising measure while awaiting hospital transfer — the procedure: with the patient supine and penile skin cleaned with antiseptic, a 16-21G butterfly needle is inserted into the corpus cavernosum at the 3 or 9 o'clock position at the base of the penis (avoiding the urethra at 6 o'clock and the dorsal vessels at 12 o'clock). Dark, deoxygenated blood is aspirated (typically 30-50 mL) — immediate improvement in rigidity confirms correct placement. If the aspirate is bright red, this suggests high-flow (non-ischaemic) priapism, and corporal aspiration alone is not the treatment. In practice, most GPs will not have aspiration needles available in primary care — the priority is 999 transfer. Any GP who does perform aspiration must document the procedure, the aspirate colour, and the outcome, and ensure hospital transfer occurs regardless of short-term improvement.

The sickle cell priapism emergency plan is a critical safety intervention that should be provided to every male with sickle cell disease at adolescent review — priapism in SCD typically begins as 'stuttering priapism' (repeated short episodes lasting <3 hours) before progressing to a prolonged ischaemic episode. The key patient education points: (1) any erection lasting more than 2 hours that is not responding to cold compress, gentle exercise, or ejaculation should be treated as an emergency (attend A&E immediately — do not wait for 4 hours); (2) at home: warm bath, gentle exercise, ejaculation (if erection is partial — full rigid priapism does not resolve with these measures); (3) the A&E team should be told immediately on arrival that the patient has sickle cell disease with priapism — this triggers the SCD priapism protocol including IV fluids, analgesia, O₂, and urology consultation. The SCD priapism protocol should be documented in the patient's GP records and shared with their haematologist.

The documentation of the penile examination at every consultation for penile symptoms is a medicolegal standard — specifically: (1) whether the foreskin was retracted (if intact); (2) the description of any visible lesion (size, colour, morphology, base hardness); (3) whether inguinal lymph nodes were palpated; and (4) the decision regarding 2WW referral, with documented reasoning if referral was not initiated. A GP who treats a penile ulcer three times with topical antifungal cream over 6 weeks without biopsy or referral, and who does not document adequate examination findings or 2WW consideration, has created a defensible medicolegal scenario. The minimum documentation standard for any penile lesion that has persisted beyond 2 weeks: 'Penile lesion [describe]: [size] × [size] mm, [location], [colour], [induration yes/no], [duration]. Patient [age], [smoking/alcohol status]. 2WW referral [initiated/not initiated, with reasoning]. Safety-net: review if not healed in 1 week / referred if not healed in 3 weeks.'