Catastrophic Kawasaki disease or juvenile Polyarteritis nodosa?

Juvenile Polyarteritis nodosa (PAN) and Kawasaki Disease (KD) are disseminated vasculitides of unknown cause affecting small- and medium-sized vessels in children. We present an unusually severe case that fulfilled criteria for both KD and PAN. The diagnosis, overlapping clinical features, and treatment options for the 2 diseases are discussed.

A 3-year-old girl with systemic vasculitis is presented. We compare our case to 4 other cases reported in the literature which presented with a similar diagnostic dilemma. A review of the medical literature and a qualitative analysis of the diseases were performed, with emphasis on overlapping features, atypical cases, and treatment options.

Many features of KD and PAN are shared; however, there are some clinical features that could help differentiate one from the other. Fever, weight loss, rash, abdominal pain, arthritis, coronary arteritis, peripheral gangrene, anemia, leukocytosis, thrombocytosis, and elevated C-reactive protein are among many of the features that are shared by both diseases. However, KD also has unique clinical features that include conjunctivitis, changes in the lips and mouth, desquamation of the fingertips, and gallbladder hydrops, whereas renal involvement in KD is rare.

Occasionally juvenile PAN and KD share clinical manifestations, and when they do, it may be impossible to differentiate between them. Treatment should be directed according to the severity and persistence of these clinical manifestations.