PRIAPISM

Priapism is an involuntary, prolonged erection unrelated to sexual stimulation and unrelieved by ejaculation and it is usually very painful.

Priapism is an uncommon condition that needs immediate medical attention. Prompt treatment for priapism is usually needed to prevent tissue damage that could result in the inability to get or maintain an erection (erectile dysfunction).
 
SYMPTOMS
symptoms may vary depending on the type of priapism. There are two main types: ischemic and nonischemic priapism.
 

Ischemic priapism

Ischemic, also called low-flow, priapism is the result of blood not being able to leave the penis. It's the more common type of priapism. Signs and symptoms include:

• Unwanted erection lasting more than four hours
• Unwanted erection off and on for several hours (stuttering priapism)
• Rigid penile shaft, but usually soft tip of penis (glans)
• Usually painful or tender penis

Nonischemic priapism

Nonischemic, or high-flow, priapism occurs when too much blood flows into the penis. Nonischemic priapism is usually painless. Signs and symptoms include:

• Unwanted erection lasting at least four hours
• Erect but not rigid penile shaft

CAUSES

Priapism occurs when some part of this system — the blood, blood vessels or nerves — changes normal blood flow. Subsequently, an unwanted erection persists. Factors that can contribute to priapism include the following.

Blood disorders

Blood-related diseases may contribute to priapism — usually ischemic priapism, when blood isn't being able to flow out of the penis. These disorders include:

• Sickle cell anemia
• Leukemia

Prescription medications

Priapism, usually ischemic priapism, is a known side effect of a number of drugs. The following drugs can sometimes cause priapism:

• Oral medications used to manage erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra)
• Drugs injected directly into the penis to treat erectile dysfunction, such as papaverine
• Antidepressants, such as fluoxetine (Prozac) and bupropion
• Drugs used to treat psychotic disorders, such as risperidone and olanzepine
• Blood thinners, such as warfarin and heparin

Alcohol and drug use

 Possible causes include:

• Recreational use of erectile dysfunction drugs
• Drinking too much alcohol
• Use of illegal drugs such as marijuana or cocaine

Injury

A common cause of nonischemic priapism  is trauma or injury to your genitals, pelvis or the perineum, the region between the base of the penis and the anus.

COMPLICATIONS

Ischemic priapism can cause serious complications. The blood trapped in the penis is deprived of oxygen. When an erection lasts for longer than four hours, this oxygen-poor blood can begin to damage or destroy tissues in the penis. As a result, untreated priapism may cause:

• Erectile dysfunction, the inability of the penis to become or stay erect with sexual arousal
• Disfigurement of the penis

REFERENCES
1.Priapism. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec17/ch226/ch226j.html. Accessed March 14, 2013.
2. www.mayoclinic.org/diseases-conditions/priapisms
3. Burnett AL, et al. Priapism: Current principles and practice. Urology Clinics of North America. 2007;34:631