What causes an extremely high or extremely low ESR?
• Markedly elevated ESR (>100 mm/hour)
• Infection, bacterial (35%)
• Connective tissue disease: giant cell arteritis, polymyalgia rheumatica, SLE, other vasculitides (25%)
• Malignancy: lymphomas, myeloma, others (15%)
• Other causes (25%)
• Markedly low ESR (0 mm/hour)
• Afibrinogenemia/dysfibrinogenemia
• Agammaglobulinemia
• Extreme polycythemia (hematocrit > 65%)
• Increased plasma viscosity
