Kikuchi Fujimoto disease
Kikuchi–Fujimoto disease is a histiocytic, necrotizing lymphadenitis. Most patients are aged <40 years (range 2–75 years) and previously well. The most common presentation is fever (30%–50%) and cervical lymphadenopathy (80%–100%). Fever is low grade and lasts 1 to 4 weeks. Cervical adenopathy is usually unilateral and affects the posterior more than the anterior lymph nodes. Up to 20% can have other nodal involvement. Nodes are usually <2 cm, firm, discrete, and mobile. Some patients (up to 50%) have a flu-like prodrome with extranodal involvement including night sweats, joint pain (7%), variable rashes (5%–30%), weight loss (10%), gastrointestinal (GI) symptoms, neurologic involvement (ataxia, aseptic meningitis), hepatosplenomegaly (3%), as well as others. Laboratory evaluation can show an elevated ESR (40%–70%), leukopenia (25%), atypical lymphocytes (25%), and elevated liver function tests (especially lactate dehydrogenase). ANA and RF are negative and if positive suggest an associated rheumatic disease. Lymph node biopsy will establish the diagnosis and exclude lymphoma, infections (tuberculosis, others), sarcoidosis, and unicentric Castleman’s disease that can present with cervical adenopathy. The biopsy classically shows necrosis without a neutrophilic infiltrate. Histiocytes and CD8 + T cells predominate. The etiology is unknown but suspected to be an immune response to an infectious agent such as EBV. Most patients (90%) improve in 1 to 6 months without treatment. Others will have relapses (3%) or persistent symptoms which can be treated with hydroxychloroquine, corticosteroids, or IV immunoglobulin.