Recurrent priapism in sickle cell trait with protein S deficiency.

We report the case of a young Omani man, a regular blood donor, who presented twice in two months, with painful penile erection lasting more than 12 hours. The patient is known to have sickle cell trait [HbS 34.6%]. Although the first episode of penile erection settled with aspiration of blood and local injection of epinephrine, on the second occasion necessitated cavernosal glandular shunting. A subsequent investigation revealed a mild protein S deficiency. Although priapism is known to occur in sickle cell disease, it is unusual in sickle cell trait. Association of mild protein S deficiency with erythrocytosis could have precipitated the onset of priapism.