musculoskeletal and connective tissue disorders
Polyarteritis Nodosa (PAN)
Etiology of PAN
Most cases are idiopathic. About 20% of patients have hepatitis B or C. The cause of polyarteritis nodosa is unknown, but immune mechanisms appear to be involved. The variety of clinical and pathologic features suggests multiple pathogenic mechanisms. Drugs may be a cause. Usually, no predisposing antigen is identified. Patients with certain lymphomas and leukemias, Rheumatoid Arthritis (RA) , or 