Vasculitis similar to polyarteritis nodosa may be an occasional secondary or associated manifestation of other diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).
Polyarteritis nodosa is uncommon; estimates of its incidence in the general population have ranged from about 5-10 per million persons per year. The disease is twice as common in men. It may occur in children and the elderly, but it is more common in middle age.
Constitutional symptoms such as fever and malaise are usually present. Cutaneous manifestations include palpable purpura, infarctive ulcers of varying sizes and livedo reticularis. Joint pain is common, but synovitis is less frequent.
Multiple mononeuropathies are the most typical neurologic manifestation, and occur in at least half of patients. Sharp sudden pain or paraesthesias in the distribution of a peripheral nerve are often the first symptoms, followed by weakness of the muscles supplied by that nerve. Several nerves may become involved progressively, resulting in severe diffuse polyneuropathy.