Polyarteritis Nodosa (PAN)

What is Polyarteritis Nodosa?
Statistics on Polyarteritis Nodosa
Risk Factors for Polyarteritis Nodosa
Progression of Polyarteritis Nodosa
How is Polyarteritis Nodosa Diagnosed?
Prognosis of Polyarteritis Nodosa
How is Polyarteritis Nodosa Treated?
Polyarteritis Nodosa References
Drugs/Products Associated with Polyarteritis Nodosa

What is Polyarteritis Nodosa?

Polyarteritis nodosa (PAN) is a multisystem disease that affects small to medium sized blood vessels. Typically it affects the renal, intestinal, muscular and cardiac circulations.

Statistics on Polyarteritis Nodosa

Polyarteritis nodosa is rare. Incidence ranges from 2-6 per 100 000 people in most populations, but may be higher in populations where hepatitis B is common.

Risk Factors for Polyarteritis Nodosa

PAN can occur at any age but is most common around 40-60 years. Men are twice as likely to be affected as women. 30% of patients with PAN also have an active hepatitis B infection. In the majority of patients, the cause of PAN is presently unknown.

Progression of Polyarteritis Nodosa

PAN may affect any organ system in the body.

Renal system: 60% of patients with PAN have renal involvement, including renal failure or hypertension.

Musculoskeletal system: Symptoms manifest as arthritis or myalgia (muscle pains).

Central nervous system: symptoms incluede transient blindness in one eye and bleeding in the brain. Global brain dysfunction and seizures may occur due to metabolic disturbances secondary to multiple organ failure. Paralysis may occur due to spinal cord compression.

Peripheral nervous system: Peripheral neuropathy develops in as many as 60% of patients.

Gastrointestinal tract: may cause sysmptoms such as abdominal pain, nausea and vomiting, bleeding, bowel perforation.

Skin: About 40% of patients develop a rash, bruising, nodules and Raynaud phenomenon.

Cardiovascular system: Cardiac disease affects 35% of patients with PAN. The symptoms and signs include congestive heart failure, heart attack, and pericarditis (inflammation around the heart).

How is Polyarteritis Nodosa Diagnosed?

A number of tests may help make the diagnosis of PAN:

blood tests

angiography (scan of blood vessels) which shows blockage of arteries travelling to organs

a biopsy (sample of skin or muscle) shows changes in small to medium sized arteries.

Prognosis of Polyarteritis Nodosa

Untreated, PAN has a high mortality rate. 5 year survival following treatment with corticosteroids and cyclophosmide is currently better than 80%.

How is Polyarteritis Nodosa Treated?

Treatment of PAN has improved greatly over the past few decades. Before the availability of effective treatment, PAN was fatal in most patients within months to years, usually as a result of kidney or heart complications. Today PAN is treated with a combination of steroids and chemotherapy agents. This brings about cure or remission in 90% of patients.

Polyarteritis Nodosa References

[1] Chung S. Polyarteritis Nodosa. eMedicine 2004. [available online @ http://www.emedicine.com/neuro/topic314.htm][2] Cotran, Kumar, Collins. Robbins Pathological Basis of Disease, 6th ed. WB Saunders, United States of America (1999).[3] Hankey G., Wardlaw J. Clinical Neurology. Demos Medical Publishing, United Kingdom, 2002. [4] Savage, Harper, Cockwell, et al. ABC of arterial and vascular disease. BMJ 2000;320:1325-1328.[5] The John Hopkins Vasculitis Center. [available online @ http://vasculitis.med.jhu.edu/typesof/polyarteritis.html][6] Watts, Scott. ABC of Rheumatology: Rashes and Vasculitis. BMJ 1995;310:1128-1132.