Co-occurrence of Kikuchi-Fujimoto's disease and Still's disease: case report and review of previously reported cases.

Kikuchi-Fujimoto's disease (KFD) and adult-onset Still's disease (AOSD) are rare inflammatory conditions with some overlapping features. We encountered a 22-year-old male patient who presented with daily fevers, neck discomfort, and sore throat and subsequently developed rash, arthritis, and cervical lymphadenopathy. Biopsy of the skin rash was consistent with KFD skin involvement. Given that the patient also met criteria for AOSD, a final diagnosis of KFD/AOSD co-occurrence was made. Anti-IL-1β therapy with anakinra resulted in rapid resolution of all symptoms. A literature search identified eight more cases of KFD/AOSD. Fever, rash, arthritis, and lymphadenopathy were present in all patients. No case report demonstrated an association of rash eruption clearly associated with fever spikes. Duration of symptoms ranged from 3 weeks to 10 years. Seven patients had leukocytosis, six had anemia, and five demonstrated elevated ferritin and/or decreased glycosylated ferritin. Seven patients had elevated erythrocyte sedimentation rate (ESR), and seven had transaminitis. Eight of nine patients had no evidence of infectious disease. Autoantibodies were absent from all patients. KFD and AOSD are very rare diseases, yet they may overlap. The two conditions not only share several clinical and laboratory characteristics but also differ in characteristic ways. Given the rapid response observed with anakinra in the index patient, IL-1β likely plays a role in both diseases.