Atypical Presentation of Incomplete Kawasaki Disease: A Peripheral Facial Nerve Palsy.

BACKGROUND: Kawasaki disease (KD) is a multisystem vasculitic disease. Coronary artery aneurysms (CAAs) are the most important and life-threatening complication of KD. Various neurologic complications have been described to occur in 1-30% of patients with KD, but peripheral facial nerve palsy (FNP) is rare (0.9%). CASE REPORT: We describe a 5-month-old male infant who presented to us with unilateral left infranuclear FNP in the convalescent phase (day 18 of illness) of incomplete KD. The initial diagnosis was not made during the first 10 days of illness (therapeutic window for immunoglobulin treatment) as he was suspected to have hand-mouth-foot disease. We believe that both the delay in diagnosis and treatment of an atypical presentation of KD, combined with the more severe vasculitis and inflammatory burden reported in these cases, contributed to the development of CAA in our patient. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the importance of considering KD diagnosis in children with prolonged unexplained fever, even with incomplete diagnostic features, as well as the need to be aware of unusual manifestations, such as FNP. Atypical cases like this may be at increased risk of CAA because of delayed diagnosis and a higher inflammatory burden; therefore, a more aggressive treatment approach may be necessary.