AKT · Renal & urology/Scrotum & male GUlow yield

Phimosis & paraphimosis

Non-retractile foreskin (phimosis) / trapped retracted foreskin causing a constriction (paraphimosis)

Overview

Two foreskin problems with very different urgency. Phimosis is a non-retractile foreskin (physiological in young boys; pathological from scarring/lichen sclerosus/BXO in older patients). Paraphimosis is a urological EMERGENCY: a retracted foreskin trapped behind the glans forms a constricting band causing painful swelling and, if not reduced, glans ischaemia.

Recognise

Phimosis: foreskin won't retract; ballooning on voiding, recurrent balanitis; pathological scarred white ring (lichen sclerosus/balanitis xerotica obliterans) in older patients
Paraphimosis: a retracted foreskin stuck behind the glans → progressive painful swelling/oedema of the glans; often iatrogenic (foreskin not replaced after catheterisation/examination)
Physiological phimosis is normal in young boys and usually resolves with age

Red flags

PARAPHIMOSIS → urological emergency: reduce promptly to prevent glans ischaemia/necrosis
Phimosis with a scarred white ring (lichen sclerosus/BXO) → risk of stricture and (long-term) penile cancer

Differentials & how to tell them apart

Physiological vs pathological phimosisage-appropriate non-retraction (resolves) vs scarred white ring (BXO/lichen sclerosus)

Balanitisinflamed glans/foreskin — infective/inflammatory

Penile cancerpersistent lesion/ulcer — biopsy; phimosis can hide it

Investigations

Clinical diagnosis; examine the foreskin/glans; in pathological phimosis consider lichen sclerosus/BXO (biopsy if atypical — penile-cancer risk); always replace the foreskin after catheterisation/examination to prevent paraphimosis.

Management

Paraphimosis → prompt reduction (emergency); phimosis → topical steroid/stretching or circumcision

1Distinguish the two: paraphimosis (retracted, trapped, swollen glans) is an EMERGENCY → reduce promptly (compress the oedema and replace the foreskin) to prevent glans ischaemia.Gate: Paraphimosis must be reduced without delay (ischaemia risk); always replace the foreskin after catheterisation to prevent it. Pathological phimosis (scarred white ring/BXO) carries stricture and penile-cancer risk.
2Phimosis → topical corticosteroid ± stretching, or circumcision for pathological/refractory cases; dorsal slit/circumcision if a paraphimosis won't reduce.

Paraphimosis: prompt manual reduction (compress oedema, replace foreskin) ± analgesia/block — the emergency — reduce to relieve the constriction; dorsal slit/circumcision if reduction fails

Phimosis: topical corticosteroid ± gentle stretching — can avoid surgery in some; treat balanitis/infection

Circumcision — for pathological phimosis (lichen sclerosus/BXO), recurrent problems, or refractory cases

Prevent paraphimosis — always replace the foreskin after catheterisation/examination

Key points

Paraphimosis (foreskin trapped behind the glans, painful swelling) = EMERGENCY → reduce promptly (glans ischaemia); ALWAYS replace the foreskin after catheterising. Phimosis = non-retractile foreskin (physiological in boys; pathological = scarred BXO/lichen sclerosus → stricture + penile-cancer risk) → topical steroid or circumcision.

Monitor & prognosis

Reduction success (paraphimosis); recurrence; BXO surveillance.

Paraphimosis excellent if reduced promptly; physiological phimosis resolves with age.

Source: NICE CKS; BAUS; cross-ref penile cancer