Hydrocele in a case of atypical Kawasaki disease: case report and review of diagnostic criteria

BACKGROUND: Kawasaki Disease (KD) is a self-limiting vasculitis of unknown etiology. Although there are well-recognized clinical features associated with classic KD, there have been increasing numbers of atypical clinical presentations with increased dependence on the American Heart Association diagnostic algorithm for incomplete KD. CASE PRESENTATION: We report on a child who was initially treated for Escherichia coli left pyelonephritis and Influenza A and Rhinovirus / Enterovirus upper respiratory tract infection. The child developed an acute hydrocele and a maculopapular rash during the illness course, which prompted further evaluation for concomitant atypical KD, although there were no other physical signs suggestive of classic KD at the time. Subsequent diagnosis of atypical KD was made with confirmation on echocardiography, with timely administration of intravenous immunoglobulin. CONCLUSIONS: Although there are well recognized clinical features associated with classic Kawasaki Disease, there have been increasing numbers of atypical clinical presentations with increased dependence on the American Heart Association diagnostic algorithm for incomplete Kawasaki Disease. This case report highlights the importance of considering a diagnosis of KD in a child with prolonged fever and unexplainable symptoms suggestive of inflammation, in this case, the rare presentation of an acute hydrocele. We recommend that for any child with prolonged unexplained fever, Kawasaki Disease should be considered. TRIAL REGISTRATION: Not applicable.