Introduction: Kawasaki Disease (KD) is a medium vessel vasculitis that can cause severe long-term sequela if untreated. While it is known to primarily present in children less than 5 years old, this case discusses an adolescent with classic KD presentation and demonstrates why KD should remain a primary differential even within atypical patient populations.
Case Study: 12-year-old Caucasian male first presented to the ER with complaints of fever for 5 days and an associated generalized rash. Bloodwork was only notable for elevated inflammatory markers and liver enzymes. Patient was treated with Bicillin empirically to cover for “scarlet fever”, and discharged home. Patient returned to ER the following day and was admitted due to new symptoms of conjunctivitis, swelling, and erythema of the tongue, hands and feet. CXR and TTE were normal. KD was not the initial diagnosis due to patient’s age. Clindamycin was started for broad coverage of potential infection. However, after infectious disease consultation, patient was switched to KD treatment. Patient initially improved, but a few days later, his previous symptoms worsened in addition to increasing WBC. Corticosteroids were initiated leading to significant improvement. Patient was discharged on hospital day 9th.
Discussion: Worldwide, KD is the second most common childhood vasculitis. While it typically affects children < 5 years of age, 1-6% of KD cases occur in children > 9 years of age. Patients in this age range may present with < 4 of the classic KD features (incomplete KD), increasing their risk of late diagnosis. Although our patient met complete KD, his age delayed the diagnosis. Older patients also tend to be less responsive to typical KD treatments (approximately 20% of patients) and are at greater risk of cardiac sequalae. Corticosteroids are recommended in patients who are not responding to IVIG and high dose aspirin alone. In addition, corticosteroids demonstrated a reduction in cardiac sequalae in resistant KD cases. This leads to the question, "should corticosteroids be initiated in all adolescent patients diagnosed with KD?" Our case demonstrates that while it is rare, KD should be considered in atypical patient populations if clinical correlation is consistent with classic disease presentation.
