Phimosis & Paraphimosis

Phimosis

Difficulty retracting the prepuce over the glans. The first job is to decide whether the process is physiological or pathological, because the two have opposite management.

In Australia circumcision rates have fallen from a peak of 85% in the 1950s to 19% in 2019, so non-retractile foreskin is a common presentation.

Physiological phimosis

At birth the prepuce is non-retractile, and the epithelial linings of glans and prepuce are continuous. Separation happens by desquamation, forming small spaces that coalesce into the preputial sac. Nocturnal erections and accumulated shed skin cells over the first 3-4 years of life help complete the separation.

Phimosis is physiological if penile function and voiding are unaffected. Proportion with a retractile foreskin: 40% at 1 year, 90% at 4 years, 99% at 15 years. Phimosis is present in 8% of 6-7 year olds, 6% of 10-11 year olds and 1% of 16-17 year olds; only 3% still have preputial adhesions at 17.

Ballooning of the foreskin on micturition is common between 2 and 4 years, is self-limiting, and does not affect the bladder or the ability to void. On attempted retraction the orifice looks moist, supple and unscarred, with pouting of the inner mucosa.

Treatment of physiological phimosis is not indicated. Explain the natural history and reassure. Forceful retraction is what causes the inflammation and scarring that produces true phimosis.

Pathological phimosis

Non-retractile foreskin persisting beyond puberty, or a previously retractile foreskin becoming non-retractile, with problematic voiding or dyspareunia. The usual cause is balanitis xerotica obliterans (BXO) — penile lichen sclerosus.

Findings that point to pathology:

• Stenosis, scarring and pallor of the preputial opening
• A sclerotic constricting band 1-2 cm proximal to the distal end
• Whitish discolouration of the peri-meatal area with an erythematous patch (pathognomonic of BXO)
• Pinhole opening with painful erections, dyspareunia, and rarely urinary obstruction or recurrent infection
• Inability to visualise the urethral meatus on retraction

BXO has an insidious onset with irritation, local infection, dysuria or bleeding before atrophy and meatal stenosis, and can run a cyclical course with remissions. Rarely it presents as acute retention or nocturnal enuresis from chronic outflow obstruction. Untreated persistent phimosis with chronic inflammation carries a debated risk of malignant transformation; the lifetime risk is not established.

Management of phimosis

Investigations are not usually needed — laboratory tests and radiography are not required, and physiological phimosis causes no obstruction. Biopsy if the diagnosis is uncertain, and send any surgically excised skin for histology to exclude malignancy.

Pathological phimosis is best treated with upfront topical corticosteroid therapy, referred for circumcision if refractory. Use betamethasone valerate 0.05% TDS for 2-4 weeks with gentle daily retraction attempts; if there is a good response continue to a total of 6-12 weeks. Topical steroids are well studied and can render the foreskin retractable at an earlier stage, and the low risk of a short course means it can be repeated.

Circumcision is the definitive treatment for pathological phimosis, and BXO is an absolute indication for it at any age. Preputioplasty is a foreskin-preserving surgical alternative for non-BXO cases.

Differential diagnosis

• Acute balanoposthitis — purulent infection of prepuce and glans, erythema and oedema, resolves with antibiotics
• Congenital megaprepuce — rare; the whole preputial sac fills with urine, needs modified circumcision
• Preputial adhesions — normal, resolve spontaneously

Paraphimosis

A true urological emergency. The retracted foreskin becomes trapped behind the corona, strangling the glans and causing venous and lymphatic obstruction, oedema and eventually arterial compromise. Arterial flow can be affected over hours to days, leading to ischaemia and necrosis of the glans.

Most cases are iatrogenic — the foreskin retracted for cleaning, catheterisation, cystoscopy or examination and not replaced. Anyone changing a Foley catheter must routinely replace the foreskin at the end. Coital trauma and self-inflicted injury are less common causes. It occurs in about 1% of males over 16 years, most often in adolescents.

Assessment

Ask about recent catheterisation, instrumentation or cleaning, and whether the patient or a carer routinely retracts the foreskin. Paraphimosis can still occur after circumcision if excess foreskin remains.

The glans and foreskin are markedly enlarged and congested while the proximal shaft is flaccid and unremarkable, with a palpable tight constricting band. A pink glans means reasonable blood supply; dark, dusky, pale, bluish or black implies ischaemia or necrosis.

A phone report of “penile swelling” should never be dismissed without seeing the lesion — pain is not always present.

Management

Most cases reduce manually without sedation. A difficult or long-standing case needs a dorsal penile block, systemic analgesia or procedural sedation.

1. Give oral analgesia.
2. Compress the glans and oedematous foreskin firmly for several minutes, or wrap a 1-2 inch elastic bandage from glans to base over a gauze pad and leave 10-20 minutes.
3. Remove the bandage and reduce: both thumbs on the glans, index and long fingers around the trapped foreskin, slow steady pressure advancing the phimotic ring back over the glans. A little lubricant helps; too much makes it too slippery to grip.
4. If unsuccessful, a second attempt can be tried.
5. If still unsuccessful, a dorsal slit through the phimotic ring under penile block.
6. Refer to ED for urology review if reduction is not achieved.

Adjuncts described include osmotic agents (topical granulated sugar, or gauze soaked in 20% mannitol left 30-45 minutes), injected hyaluronidase, and puncture-aspiration for refractory cases. Many experts recommend against ice, since the problem is already arterial compromise distal to a constricting band.

After reduction, clean the foreskin, treat abrasions with a topical antibiotic ointment, and instruct the patient not to retract for a week.

Reducing the paraphimosis is not sufficient long-term therapy. Recurrence risk is high, so elective circumcision or dorsal slit is strongly recommended after a significant episode.

Complications: pain, infection, inflammation of the glans, and — if reduction is delayed — ischaemia or necrosis requiring debridement, glans resection or partial penectomy.