Successful switching treatment of adalimumab for refractory pyoderma gangrenosum in a patient with rheumatoid arthritis with prior use of tumour necrosis factor inhibitors: A case report and review of the literature.

Pyoderma gangrenosum (PG) is a rare chronic skin disease characterised by painful skin ulcers. There are no treatment guidelines for PG, but systemic treatments including biologics are often used. Recently, adalimumab (ADA), a fully human monoclonal antibody against tumour necrosis factor, was approved for refractory PG treatment in Japan. Herein, we report a case of rheumatoid arthritis with refractory PG 2 months after orthopaedic surgery of the foot during treatment with low-dose etanercept and methotrexate. Although adding a moderate dose of glucocorticoid did not improve her PG, the patient showed a remarkable response after switching from etanercept to ADA in a higher dose than that used to treat rheumatoid arthritis. This higher dose of ADA may be effective for the treatment of refractory PG after the failure of other tumour necrosis factor inhibitors.