Kawasaki disease malingering as juvenile dermatomyositis: case-based review: Myositis in Kawasaki disease

Kawasaki disease (KD) is a medium vessel vasculitis that predominantly affects children below 5. Diagnosis of KD is based on the presence of characteristic clinical manifestations as there are no definite diagnostic laboratory investigations for the diagnosis of this disease. Presence of atypical clinical features such as myositis often pose diagnostic challenge for the treating physicians. Presence of myositis and severe muscular weakness in KD is distinctly unusual and may lead to delays in diagnosis and administration of definite therapy. We report a 10-year-old boy who presented with fever, rash and proximal muscle and pharyngeal weakness. A clinical possibility of toxic shock syndrome or juvenile dermatomyositis was initially considered. However, he continued to have fever and developed periungual peeling of skin in fingers. Hence, a possibility of KD with myositis was considered. He showed prompt response to intravenous immunoglobulin and methylprednisolone. We also provide a review of similarly reported cases of KD myositis. It is important for clinicians to be aware of this atypical clinical presentation to avoid delays in diagnosis and treatment of KD.