A case of polyarteritis nodosa with severe lower limb ulcer that was treated with prednisolone and tocilizumab

Polyarteritis nodosa (PAN) is a rare systemic necrotising vasculitis that can lead to the formation of refractory lower limb ulcers requiring amputation. The standard treatment for severe PAN involves combination therapy with steroids and cyclophosphamide; however, some cases prove to be challenging. Recently, case reports have described the use of biological agents for PAN treatment. We present the case of a 61-year-old Japanese man with cutaneous PAN and refractory recurrent lower limb ulcers. In 2017, the patient was admitted to the hospital because of exacerbation of a right lower limb ulcer. Despite combination therapy with corticosteroids, cyclophosphamide, and endovascular therapy, the gangrene in the right lower leg progressed, and amputation was performed. The patient was temporarily stabilised with prednisolone monotherapy. In 2019, new ulcers were observed on the left lower limb. Owing to steroid resistance, subcutaneous tocilizumab (162 mg/week) was initiated. Over a few months, the ulcer healed completely, and left lower limb amputation was avoided. Therefore, tocilizumab could potentially be one of the treatment options for severe cases in the future.