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 Priapism is subdivided into 2 classifications based on

the source of blood-high flow versus low flow. Most commonly, oxygen-deprived, venous blood becomes entrapped

in the cavernosa; this is termed "low-flow" priapism, or

ischemic priapism. "High-flow'' priapism, less often seen,

results from a communication or fistula between the cavernosal arterial supply and the cavernosa itself. Because of the

oxygen-rich arterial supply, this type of priapism is also

called nonischemic priapism. High-flow priapism presents

less of a time-sensitive risk and is often non painful.

..... Phimosis and Paraphimosis

Phimosis is the inability to retract the foreskin proximally

over the glans. Causes include infection, poor hygiene,

• Corpus cavernosum aspiration and dorsa l slit are used

by the emergency physician to prevent the compl ications of priapism and paraphimosis, respectively, until

urology consultation is availa ble.

and trauma, which lead to scarring and fibrosis of the

foreskin and resultant loss of normal movement. This can

infrequently lead to urinary retention owing to blockage

of the urethral meatus. Phimosis may be normal in prepubertal males (physiologic phimosis). By age 4, 90% of

foreskins are fully retractable. A foreskin that is not fully

retractable by the end of puberty is considered pathologic

phimosis.

Paraphimosis is the inability to return a retracted foreskin to its original, anatomic position. Paraphimosis results

when the foreskin is not returned to its normal position

overlying the glans penis. This commonly occurs as an

iatrogenic complication, such as after an exam of the glans

or Foley catheter placement in a debilitated patient. The

retracted foreskin acts in a tourniquet manner, restricting

venous outflow from the glans penis. This eventually leads

to local swelling, inflammation, ischemia, and necrosis of

the involved tissue, causing a urologic emergency.

..... Balanoposthitis

Balanoposthitis is a combination of inflammation of the

glans penis (balanitis) and inflammation of the foreskin

(posthitis). This condition occurs most commonly in uncircumcised males as a result of poor hygiene, local/recurrent

irritation, or infection (usually Candida, Gardnerella, or

Streptococcus pyogenes species). Balanoposthitis may be the

sole presenting symptom of diabetes mellitus.

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CLINICAL PRESENTATION

� History

CHAPTER 42

Important historical features of priapism include past

medical history, duration of symptoms, causative events,

and medications. Medical causes of priapism include sickle

cell disease or thalassemia (particularly in children) and

leukemia or multiple myeloma in the elderly. The duration

of priapism is also of significance. Prolonged venaocclusive priapism (usually >6 hours) leads to fibrosis of

the corporal tissue resulting in impotence. Patients should

additionally be questioned about possible trauma to the

penis, as high-flow priapism usually results from a traumatic fistula between arterial and venous supply. A thorough medication history should also be obtained.

Medications implicated in priapism include antipsychotics

(trazodone, thioridazine) and agents for erectile dysfunction (papaverine, prostaglandin E1, sildenafil). Cocaine use

is also a common cause of priapism.

For phimosis and paraphimosis, patients should be

questioned about duration of symptoms, general hygiene,

and foreskin care. Duration of symptoms is particularly

important for paraphimosis, as arterial compromise can

lead to glans ischemia and necrosis.

Because of the strong association between diabetes and

balanoposthitis, a thorough past medical and family history should be sought. Additionally, symptoms such as

fevers, myalgias, and lymphadenopathy may suggest possible systemic involvement.

� Physical Examination

For any of the penile disorders, a general exam of all male

genitourinary organs (penis, scrotum, testicles, perineum,

anus/rectum, and prostate) should be performed. Inspection

alone will often lead one to the diagnosis of priapism, paraphimosis, or balanoposthitis (Figure 42-1). If the penile

foreskin is present, check for proper retraction/replacement. Inspect the underlying glans, looking for erythema,

warmth, or discharge. Do not mistake paraphimosis with

balanoposthitis, as both may present as a painful, edematous foreskin and glans. The key difference is that the foreskin is retracted and nonreducible in paraphimosis.

DIAGNOSTIC STUDIES

Because most penile disorders can be diagnosed by history

and physical exam alone, few diagnostic measures are nec ­

essary. To help distinguish between high- and low-flow

priapism, an arterial blood gas (ABG) of corporal aspirate

may be obtained. Because low-flow priapism is an isch ­

emic process, the ABG will show deoxygenated blood. If

the ABG resembles a normal, oxygenated sample, the

patient likely has high-flow priapism. Bedside ultrasound

also has a role in priapism. If arterial flow can be seen

using the color Doppler mode, then high-flow priapism is

likely present. A complete blood count and reticulocyte

Figure 42-1. Paraphimosis.

count can be helpful in sickle cell disease or to rule out

leukemia.

Paraphimosis and phimosis are generally bedside diag ­

noses and require no further diagnostic testing.

Because of the strong association of diabetes mellitus

and balanoposthitis, a bedside glucose test is warranted.

For recurrent or difficult to treat infection, a culture may

help to better guide treatment.

MEDICAL DECISION MAKING

Of the penile disorders discussed, low-flow priapism and

paraphimosis are the two that require time-sensitive

diagnosis and treatment or permanent penile damage may

ensue.