P2.K218: Cervical Spine Arthritis as a Manifestation of Kawasaki Disease

Introduction: Kawasaki disease (KD) is an acute systemic vasculitis with well-defined clinical diagnostic criteria. Atypical or rare clinical features can potentially delay diagnosis and treatment of KD, risking potential cardiac sequelae. We report the case of a 5-year-old female presenting with recurrent fever and persistent polyarthritis with cervical spine (C-spine) involvement following KD treatment.

Case Description: A 5-year-old Korean female presented to a community hospital with fever and cough and was initially treated for pneumonia. The next day, she developed 5/5 diagnostic criteria for KD with a normal echocardiogram. She was treated with IVIG and aspirin and discharged on day 7, after remaining afebrile for 72 hours. Fever recurred that evening, along with painful, limited neck movement. She was readmitted and had a neck CT scan which showed retropharyngeal rim-enhancing lesions. Antibiotics and dexamethasone were administered for suspected retropharyngeal abscesses. Neck MRI (Image 1) on day 14 showed improvement of the lesions, but also showed joint effusions in the C-spine. She was discharged on day 18 on naproxen after defervescence. On day 19, fever recurred, with new painful swelling of both wrists and ankles, in addition to persistent neck pain. Upon readmission, her SARS-CoV-2 PCR was positive. Differential diagnoses included refractory KD, which was favored, versus MIS-C or systemic juvenile idiopathic arthritis (sJIA), based on her symptoms and lab results (Table 1). Echocardiogram remained normal. IVIG was not readministered due to the prolonged duration of her symptoms and significant anemia. She was treated with intravenous methylprednisolone with prompt resolution of fever and polyarthritis. She was discharged on day 23 on oral prednisolone, tapered over 2 weeks. At her 1-week and 1-month follow-up visits, she remained afebrile and arthritis-free.

Discussion: This case of refractory KD was complicated by the presence of suspected retropharyngeal abscess and C-spine arthritis. Retropharyngeal phlegmon is a well-described feature of KD, however rim-enhancing lesions are atypical for KD. C-spine arthritis is a further unique aspect of this case. Arthritis is reported in 7.5-17.6% of KD patients, typically affecting the weight-bearing joints. To the best of our knowledge, only one other case of C-spine arthritis in KD has been reported. Various conditions including cervical lymphadenitis, retropharyngeal infections, meningitis, osteomyelitis, and sJIA can present with fever, neck pain and restriction, and other KD features. While these other conditions can be severe, it is important to not exclude KD and its treatment on the basis of the presence of C-spine arthritis. In this case, suspicion for sJIA and other causes of C-spine arthritis and systemic inflammation led to delayed treatment of refractory KD.

Conclusion: C-spine arthritis is a rare manifestation of KD which may complicate diagnosis and delay treatment. This is a case of C-spine arthritis in refractory KD successfully treated with corticosteroids.