Synovial fluid cell count of 84 930/mm³in adult-onset Still’s disease

Abstract

In traditional teaching, synovial fluid cell counts over 50 000/mm3 are in keeping with septic or crystalline arthritis. We report a patient with adult-onset Still’s disease (AOSD) and associated inflammatory arthritis whose synovial fluid cell count was over 80 000/mm3. This is the highest level reported in the literature, demonstrating that in the appropriate clinical context, markedly elevated synovial cell count levels over 50 000/mm3 can be caused by inflammatory conditions like AOSD. Recognition of this is crucial to avoid inappropriate antibiotics and procedures while also ensuring correct immunosuppressive treatments are offered in a timely manner.