Priapism was first described in the English literature in an 1824 case report by Callaway.1,2 It is defined as a prolonged engorgement or erection of the penis or clitoris that lasts greater than 4 hours and occurs beyond or apart from sexual stimulation or arousal.3,4 The term “priapism” derives its origin from the name of a minor Greek god of fertility and luck named Priapus.5 He was said to have been cursed by Hera by having out of proportion genitals, ugliness, salaciousness, and ironically, impotence. A famous Pompeiian fresco graphically illustrates Priapus' plight as he weighs his massive phallus with a hanging scale.5 Male priapism is far more common than the extremely rare female form. This chapter will focus on the male priapism.
Priapism affects an estimated 1.5 cases per 100,000 person-years in the general population and 29% to 42% of sickle cell patients during their lifetimes.6–8 The most common form of priapism is often an excruciatingly painful and prolonged erection. This is frequently embarrassing to the patient and results in delays in seeking medical attention. Without swift and expert intervention, priapism can sometimes lead to permanent scarring and impotence.
Priapism is generally classified into two major subtypes, ischemic and nonischemic, although other less common subtypes exist.3 It is critical that the Emergency Physician determines which subtype the patient is presenting with because emergent management and prognosis differs considerably between them.
The most common priapism subtype is ischemic priapism. This condition is also known as low flow or vaso-occlusive priapism. This subtype of priapism poses the greatest risk of permanent penile dysfunction. It is generally thought to result primarily from an impediment to blood emptying from the penis and has a large number of associated etiologies (Table 147-1). These patients present with a very painful, rigid penis, with engorgement of both corpora cavernosa. The corpus spongiosum and the glans are usually spared, although those structures also may be involved in rare instances18 If left untreated, this condition forms a type of compartment syndrome which results in fibrosis and scarring, loss of function, and in extreme cases tissue necrosis. Even with treatment, the outcomes are often poor. Reported rates of complete erectile dysfunction after ischemic priapism range from 30% to 90%.3,7
Table 147-1 The Etiologies of Ischemic Priapism |Favorite Table|Download (.pdf)
Table 147-1 The Etiologies of Ischemic Priapism
|Etiology||Incidence||Specific conditions or substances|
Erectile dysfunction agents
Sickle cell disease
Intracavernous erectile dysfunction drug therapy
Metastatic cancer to penis
Primary penile cancer
Total parenteral nutrition
Spinal cord lesions or stenosis