Ankle abscess under the use of tocilizumab in rheumatoid arthritis; a case report

Abstract

　Attention needs to be paid to the masking of the symptoms of bacterial infections during the use of tocilizumab (TCZ). We experienced the case of a 60-year-old female patient, who was diagnosed with rheumatoid arthritis (RA) at the age of 49 and whose treatment of TCZ was started at the age of 56. In three years and eight months after TCZ was started, she presented a gradually worsening pain and swelling at the distal end of the right lower leg. The body temperature was 36.4℃, and the value of C-reactive protein (CRP) was 0.92 mg/dl on admission. Abscess formation was seen at the same site as the local inflammation in magnetic resonance imaging. Thus, drainage treatment was performed and Methicillin-resistant Staphylococcus aureus (MRSA) was detected from the abscess. TCZ was discontinued and the intravenous administration of antibiotics lasted three weeks. The body temperature did not exceed 37℃ during the course of treatment. Our case highlighted the need for judgment through clinical features and bodily symptoms rather than the value of the laboratory tests when the MRSA abscess appeared in RA patients treated with TCZ.