Polyarteritis nodosa (PAN) is a disease that results from blood vessel inflammation ("vasculitis") causing injury to organ systems. It can affect any organ in the body but commonly the muscles, joints, intestines, nerves and skin are affected. PAN can also affect the blood vessels to the kidney resulting in high blood pressure and damage to kidney function.
Since many different organ systems may be involved, a wide range of symptoms are possible in PAN. Patients who have PAN may feel generally ill and fatigued, have fevers, or have loss of appetite and weight. They may have symptoms related to areas of involvement such as pain in the muscles and/or joints, skin sores that may appear as hard tender nodules or ulcers, abdominal pain or blood in the stools occurring as a result of intestinal tract involvement, or shortness of breath or chest pain from disease affecting the heart. High blood pressure is common in PAN and usually due to vasculitis decreasing blood flow to the kidneys. PAN may affect nerves and cause abnormal sensations, numbness or loss of strength. Any combination of these symptoms may be present.
The condition affects adults more frequently than children and males more frequently than females. Most cases occur between the ages of 30 and 49.
Treatment involves medications to suppress the immune system. Therapy results in remissions or cures in 90% of cases. Untreated, the disease is fatal in most cases. The most serious associated conditions generally involve the kidneys and gastrointestinal tract. A fatal course usually involves gastrointestinal hemorrhage, infection, myocardial infarction and/or renal failure. How people with PAN do is strongly related to the severity of their illness.