Periarteritis nodosa is a rare, grave disease remarkable for its protean manifestations. Although it was first described as a clinical entity by Kussmaul and Maier in 1866, only 50 of 350 cases recorded by 1940 were diagnosed prior to death.1 Sufficient cases have been recognized antemortem during the last 15 years to attract widespread interest in the clinical manifestations as well as in pathogenetic and therapeutic problems of the disorder. Increased recognition may be largely due to awareness of the disease entity, coupled with a more ready resort to biopsy, but some absolute increase may have occurred in relationship with the increased use of such drugs as the sulfonamides; and there may be cases that formerly would have succumbed which, with modern drugs, have survived to show widespread vascular damage. It should also be realized that the scope of the term ``periarteritis nodosa'' has been greatly