Lymphadenitis is a common problem in paediatrics. It is most frequently caused by virus or bacteria infections. Kikuchi Fujimoto’s disease (KFD) or histiocytic necrozing lymphadenitis associates cervical lymphadenopathy with fever and leucopenia typically in young women. We report here two paediatric cases of KFD. The first case was an 11-year-old girl presenting with firm painless unilateral cervical and sus-clavicular lymphadenitis, weight loss but no fever. The second was a 13-year old girl with fever, unilateral cervical lymphadenitis, weight loss and asthenia. Both patients were initially treated with antibiotics but were referred for symptom persistence. Laboratory tests failed to show leucopenia and elevation of C-reactive protein. Serology screenings for bacteria, virus and autoimmune diseases were negative. Tuberculin skin test was also negative. A PET scan displayed hypermetabolic spots localized to the clinically enlarged lymph nodes. Surgical biopsy was performed and revealed the presence of histiocytic necrosis compatible with the diagnosis of KFD in both children. A few weeks after diagnosis the first patient presented with butterfly erythema and increased antinuclear antibody titer suggesting the development of systemic lupus erythematosus (SLE). She was treated with chloroquine that allowed a rapid resolution of symptoms.
In conclusion, KFD is a rare and benign cause of lymphadenitis that may occur in children. It may be associated with auto-immune diseases such as SLE. It should be considered in the differential diagnosis of prolonged cervical lymphadenopathies where infectious aetiology has been excluded. Histological examination is required to confirm the diagnosis and to exclude malignant infiltration.