While continuing outpatient treatment at our hospital, the patient developed elevated liver enzymes, increased neutrophil counts, elevated ferritin, and polyarthritis. Given the constellation of findings, AOSD was diagnosed, which was likely the underlying driver of inflammation and anemia in this case. Treatment with prednisolone and an interleukin-6 inhibitor led to symptom relief and improvement in blood test results. Here, IL6 is linked to anemia (phenotype).