P2.220: From Fever to Diagnosis: A Case of Fever of Unknown Origin and Cervical Lymphadenopathy

Introduction: Kikuchi disease is a rare, typically self-limiting inflammatory condition characterized by painful cervical lymphadenopathy and systemic symptoms like fever and malaise. The rarity of the disease and non-specific symptoms at onset make it a diagnostic challenge. Thus, it is important to shed light on this disease, its presentation and ways it may be differentiated from other conditions like systemic lupus erythematosus (SLE).

Case Description: A previously healthy, fully immunized 8 year old child presented to the emergency department with a 3 week history of intermittent fevers, rash and painful cervical lymphadenopathy not responding to oral antibiotics. On exam, she was ill-appearing, with a maculopapular facial rash, conjunctival injection, erythematous oropharyngeal ulcers, and a 2 cm lymph node on the right neck. Initial workup showed microcytic anemia, leukopenia and elevated inflammatory markers, and IV antibiotics were subsequently started. Due to lack of improvement, extensive workup including infectious, rheumatologic and hematologic/oncologic studies were performed and returned largely negative. Imaging studies including echocardiogram and CT chest, abdomen, pelvis returned without acute findings. Upon discussion with rheumatology, it was felt that her condition most likely represented Kikuchi disease versus SLE given a positive anti Smith antibody and negative anti-neutrophil antibody. Lymph node biopsy was pursued for histopathology, after which she was treated with two doses of IV methylprednisolone. Steroid therapy aided in resolution of fevers and she was discharged with close rheumatologic follow up. Lymph node biopsy ultimately showed necrotizing lymphadenitis most suggestive of Kikuchi's lymphadenopathy, and she was subsequently started on hydroxychloroquine as an outpatient.

Discussion: This case elucidates the importance of keeping Kikuchi Disease on the differential when considering fevers of unknown origin. Kikuchi Disease is extremely rare, but has been seen to affect individuals of all races and ethnicities1. This illness typically presents in individuals under the age of 402, and thus represents an important diagnosis that pediatricians should consider. The presentation of this illness is non specific with most individuals presenting with persistent fevers, a rash (which can range in appearance), cervical lymphadenopathy and neurologic changes3. Given the persistence of fevers, it can often mimic infectious, inflammatory or oncologic etiologies such as Kawasaki Disease, systemic lupus erythematosus or cancer. As such, patients may be burdened with extensive laboratory workup and imaging to get down to a diagnosis.

Conclusion: Knowledge on the presentation and treatment of Kikuchi Disease will help providers limit unnecessary workup and decrease time to diagnosis. While Kikuchi Disease is typically self limiting, decreasing time to diagnosis may be of benefit to those with a more prolonged or complicated clinical course that can be treated with steroids or intravenous immunoglobulin.