A 28 year old man presents with painful swelling and discoloration of his penis for 3 hours.

During sexual intercourse immediately prior, he suddenly experienced severe penile pain in association with a 'crackling' sound, which was followed by immediate detumescence. He is able to urinate normally, and there is no history of dysuria or urinary discoloration.

His medical history is unremarkable, and he is not on any medications. He drinks only socially, and does not smoke or use recreational drugs.

Urinalysis reveals no red cells, while a dipstick test is negative for blood.