LAUSR

An 8-year-old girl was referred with fever and painful erythematous nodules located over the extremities, and arthritis of the bilateral ankles and knees. She had no remarkable past history other than the development of pharyngitis 1 week before admission. Laboratory results indicated leukocytosis (13 410 cells/mm), elevated C-reactive protein (1.4 mg/dL), and erythrocyte sedimentation rate, 61 mm/h. Anti-streptolysin O titer was increased at 2380 IU/mL. The symptoms resolved in response to short-term antibiotics, ibuprofen, and prednisolone, but painful erythematous nodules, myalgia, and fever were exacerbated upon steroid withdrawal. On fat-suppressed T2weighted magnetic resonance imaging of the lower extremities, multiple high-intensity nodular lesions were noted throughout the subcutaneous tissue and subfascial muscle tissue. Skin biopsy of an erythematous nodule indicated necrotizing vasculitis. No other visceral arterial involvement was observed. The diagnosis of cutaneous polyarteritis nodosa (cPAN) was made. She was treated with prednisolone, and maintained with cyclosporine and monthly infusions of cyclophosphamide, but flare of cPAN occurred upon steroid withdrawal. Tonsillectomy was performed, but flare occurred again. Etanercept (ETA; 0.4 mg/kg twice per week) was started and led to marked improvement in symptoms within 3 weeks (Fig. 1). Approval for the off-label use of ETA was obtained from the institutional review board at Kanazawa University, and written informed consent was obtained from the patient’s parents. The patient achieved complete clinical remission and steroid use was stopped. No side-effects were observed. Cutaneous polyarteritis nodosa is a cutaneous necrotizing vasculitis that predominantly targets medium-sized arteries with minimal systemic involvement. cPAN often follows a relapsing and chronic course and some patients with cPAN are refractory to immunosuppressive treatment. The time to glucocorticoid-free clinical remission of cPAN is as long as in systemic PAN in childhood.