Chamberlain JL, Perry LW. Infantile periarteritis nodosa with coronary and brachial aneurysms: a case diagnosed during life. J Pediatr 1971;78:1039-42. Prior to the recognition of Kawasaki disease, or mucocutaneous lymph node syndrome, as it was originally called, an entity entitled periarteritis nodosa existed, to capture infants and others presenting with rash and vasculitis, including infants with coronary aneurysms and no other known etiology. Chamberlain and Perry described a case of this rare, and often undiagnosed ante-mortem condition, based on a combination of clinical history, physical examination (including palpation of brachial aneurysms), and angiography of the coronary arteries and arterial tree, a daunting task in a 20-week old infant in 1971. The child survived after weeks of chronic inflammatory symptoms. I had a similar patient, treated in an era when gamma globulin was not available to dramatically shorten the clinical course, who suffered for weeks with inflammation, lost a digit to vaso-occlusion, and required a coronary artery bypass. Periarteritis nodosa still exists, but is much rarer and more circumscribed, as the etiology of overlapping conditions has been identified, or syndromic identification has replaced use of that term. Unfortunately, our perplexity regarding the etiology of acute pediatric inflammatory conditions associated with vasculitis. remains as well. The patient in this report, as was mine, would now be diagnosed with Kawasaki disease; the description of that cluster of clinical findings was a clinical revelation, as have been related diagnostic and therapeutic innovations over the last 40 years. Nonetheless, the cause remains unknown. And now, in the last year, comes another revelation, multisystem inflammatory syndrome in children, re-energizing conversations on the etiology, mechanism, and treatment of childhood inflammatory vascular injury.1Rowley A.H. Multisystem inflammatory syndrome in children and Kawasaki disease: two different illnesses with overlapping clinical features.J Pediatr. 2020; 224: 129-132Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar The extraordinary effort undertaken by Chamberlain and Perry, with the tools at their disposal, to provide knowledge about a perplexing condition, was repeated by the early investigators of Kawasaki disease, with results benefitting many children. Nature has thrown us another curve, and we have newer anti-inflammatories and cardio-respiratory support to improve outcomes. Maybe we will find some causes too.