This is a relatively rare condition occurring with an annual incidence of 4.5 in 100,000 males commonly between the ages of 1–25 years. It is characterised by a sudden onset of severe hemi-scrotal pain which may radiate to the lower abdomen or flank. It may also be associated with nausea or vomiting and there may be a history of minor trauma or previous intermittent episodes of similar pain. Urinary symptoms may occasionally be present with torsion.

Examination may be difficult due to the severity of the patient’s pain. However, classically the testis may have a horizontal and high position with an absent cremasteric reflex. However, reliance on the presence or absence of these findings should not on their own exclude torsion.

Colour Doppler ultrasonography if available may provide additional diagnostic evidence of absence of testicular blood flow. The torsion may be identified as a snail-shaped mass, a doughnut shape or a target with concentric rings known as the whirlpool sign. In the later stages of torsion, there is venous congestion and a lack blood supply to the affected testis with testicular enlargement and heterogeneity indicating severe ischaemia.

The assessment should also exclude other possible diagnoses which include epididymo-orchitis, torsion of a hydatid cyst of morgani, referred pain from a ureteric calculi or an atypical renal tumour. It is important that if there is any doubt regarding the diagnosis, the patient should have an urgent scrotal exploration.

The only method of completely excluding and simultaneous treating torsion is with surgical exploration. This should be performed as early as possible (ideally within 6 h of the onset of pain), on the next available operating list.

Whilst the highest salvage rates have been observed if de-torsion is performed within the 6 h window, many studies have reported good salvage rates up to 48 h after symptom onset. In addition the salvage rate is also dependant on the degree of torsion. In men with equivocal appearances in theatre where the testis is returned to the scrotum, the patient should be counselled about post operative testicular atrophy.

Ischaemic priapism is a compartment syndrome of the penis with stasis of hypoxic blood within the corpora cavernosa with resultant smooth muscle necrosis and fibrosis. Men present with a rigid, painful erection. Although 30% are idiopathic, it may be the first presentation of haematological malignancies or abnormalities. Other risk factors which should be elicited from the history include: sickle cell disease and the use of antipsychotics, intracavernosal prostaglandin injections and recreational use of phosphodiesterase-5 inhibitor (PDE5i). The diagnosis is confirmed by a penile blood gas aspiration which reveals hypoxia, acidosis and glucopenia.

Non-ischaemic priapism usually occurs following penile or perineal trauma; classically a straddle injury. The injury may be very minor and results in an arteriocavernosal fistula. It is less common than ischaemic priapism. The penis is semi-tumescent and painless. Penile blood gas aspiration reveals either normal pO₂ and pH or a mixed compensated picture. The diagnosis is confirmed on penile colour Doppler which reveals an increase in the peak systolic velocity in the cavernosal artery and the abnormal fistula. We recommend these men should be treated promptly with angio-embolisation of the fistula. Conservative management is not advised.

These men are in severe pain and therefore adequate analgesia is vitally important. This should be with aopiate analgesia and a penile block (10 ml 1% lignocaine with 10 ml 0.5% Marcaine). They may also benefit from the use of entonox. In the cases of men with sickle cell disease, they should be kept well hydrated and discussed with the local haematologist for consideration of an exchange transfusion. Analgesia is of even more importance in these men as their priapism may have been precipitated by an acute crisis.