Polyarteritis group of systemic vasculitis--new diagnostic criteria.

We have used new diagnostic criteria to define patients with the polyarteritis nodosa (PAN) group of vasculitis. These were the combination of a necrotising glomerulitis without diffuse deposits of immunoglobulins or complement components in a patient presenting with systemic disease and multi-organ involvement. Twenty-two patients who fulfilled these criteria presented to our unit between 1975 and 1982. The diagnosis of PAN was confirmed by traditional histological criteria in eight. We anticipate that the use of these criteria will lead to earlier diagnosis and thereby improve the management of this potentially lethal disorder.