P2.L221: Deciphering Kawasaki Disease: Lymphadenopathy as a Diagnostic Conundrum

Introduction: Kawasaki disease (KD) is a small vessel vasculitis characterized by fever and classic manifestations including rash, conjunctivitis, abnormalities of the extremities, oral mucosa and cervical lymphadenopathy. Early detection of KD is challenging due to often incomplete observation of clinical symptoms. Incomplete KD is associated with higher incidence of coronary artery disease due to delays in diagnosis.

Case Description: A 21 month old previously healthy male presented to the emergency room with 4 days of high fevers, rash and unilateral neck swelling for which he was prescribed amoxicillin-clavulanate. Ultrasound of the lymph node demonstrated signs of early necrosis and he was admitted to the general pediatric service with a presumed diagnosis of bacterial lymphadenitis on IV clindamycin. Initially, while his rash and neck swelling improved, his daily fevers persisted. On day 5 of fever, rheumatology and cardiology were consulted. An echocardiogram showed no evidence of coronary artery aneurysm or ectasia. An infectious etiology was thought to be most likely given node size improvement and absence of conjunctivitis and oral mucosa involvement, thus antibiotics were continued. However, on day 8, he remained persistently febrile with rising inflammatory markers, increased irritability, decreased oral intake, new periorbital swelling and peripheral edema of the upper and lower extremities. With ≥5 days of fever, rash, cervical lymphadenopathy, extremity edema and laboratory findings of CRP elevation, hypoalbuminemia, pyuria and ALT elevation, the patient met diagnostic criteria for incomplete KD. He was initiated on high-dose aspirin, steroids and IVIG. After receiving IVIG the patient remained afebrile with significant improvement in his symptoms and inflammatory markers.

Discussion: Lymphadenopathy is one of the least common clinical criteria in patients with KD and as a presenting symptom may lead to delays in diagnosis and treatment. This case illustrates the difficulty in discriminating between bacterial lymphadenitis and KD upon first presentation.

Conclusion: Failure to respond to antibiotics and persistent fever should prompt consideration of alternate diagnoses including incomplete KD.