Etiology of the Mucocutaneous Lymph Node Syndrome, and the Streptococcus Hypothesis

The epidemiology, clinical and laboratory findings, and the progress of the mucocutaneous lymph node syndrome (Kawasaki disease) were analyzed for clue to its etiology. Though there are several controversies against the possibility of Streptococcus hemolyticus in the etiology, such as failure of getting regularly the agent by culture from patients and inefficacy of antibiotics, close similarity in symptomatology and common possession of cardiovascular complications by the syndrome and streptococcal infection are very suggestive of the possibility. Suppurative or septic forms of streptococcal infections in infants and young children, which were seen at the time when antibiotics were not used, showed nearly identical curves of age incidence to that of this syndrome. Sero‐epidemiological study by Kusama et al., which has revealed the percentage distribution curve by age of “ASO negative subjects” is also very similar to the age incidence curve of this syndrome, seems to offer another support to the hypothesis. The well documented cross reactivity between streptococcus cell wall and cardiac muscle or arteriolar smooth muscle fibers of mammalian, seems to be another support to the theory.