Phimosis - Disorders of the male genital system

Phimosis

Definition

Narrowing of the penile orifice due to contraction of the foreskin.

Aetiology/pathophysiology

Normally the foreskin does not retract at birth and it may be months to years before it becomes retractile. In congenital phimosis, the orifice is too small from birth causing difficulty in micturition. If the foreskin is not retractable beyond childhood, there may be difficulty in cleaning under the foreskin predisposing to infection (balanitis) and carcinoma of the penis.

Clinical features

A young child with congenital phymosis may have difficulty with micturition, with ballooning of the prepuce as it becomes full of urine.

In adolescence and adulthood, if the foreskin does not retract fully, pain may be felt on erection and with sexual intercourse.

Complications

Recurrent balanitis may occur due to secretions collecting under a poorly retractile foreskin. Balanitis causes pain and a purulent discharge.

If a poorly retracting foreskin remains retracted after an erection it can act as a tight band causing oedema and engorgement of the glans (paraphimosis) due to disruption of venous blood flow.

Phimosis increases the rate of penile cancer by at least 10-fold.

Management

Symptomatic phimosis is treated by elective circumcision. Circumcision is not required in asymptomatic young children, unless for religious reasons. In cases of acute paraphimosis, the band is excised under general anaesthetic if the foreskin cannot be drawn forwards and circumcision is advocated.