A case of concurrent Kikuchi-Fujimoto Disease and Neuropsychiatric Lupus in a Patient with Rheumatoid Arthritis and Systemic Lupus Erythematosus Overlap Syndrome

Kikuchi-Fujimoto disease is a rare, self-limited, histiocytic necrotizing lymphadenitis characterized by cervical lymphadenopathy and fever. An association has been made between the presence of this disease and systemic lupus erythematosus. We describe a unique case of a 31 year old female with a previous diagnosis of rheumatoid arthritis and lupus overlap syndrome who presented with severe headache and subsequently developed altered level of consciousness and seizures. She underwent an extensive assessment which included investigations for an infectious cause, numerous imaging studies, a lymph node biopsy, a bone marrow biopsy, and a brain biopsy resulting in a final diagnosis of concurrent Kikuchi-Fujimoto disease and lupus-associated encephalitis. In these overlap patients, neurological involvement is usually mild. In contrast, our patient presented with severe neuropsychiatric involvement eventually requiring ICU admission. This case highlights the difficulty of diagnosing and managing neuropsychiatric lupus in these complex overlap patients. Early recognition is important to avoid unnecessary and potentially harmful interventions and treatments.