Abstract
A20-year-old woman with undifferentiated arthritis juvenile idiopathic arthritis（JIA）developed a red
excoriated plantar skin lesion at the age of 19 years． She was diagnosed with JIA at the age of l5 years． Her
disease was controlled with the treatment of methotrexate and etanercept（ETA）． Skin biopsy of plantar skin
lesion revealed a psoriasiform hyperplasia in the epidermis． The diagnosis of psoriasiform skin lesion induced
by ETA was made． There was no improvement with topical antibiotics and steroids． Because of severe skin
lesions，ETA was discontinued and tocilizumab therapy was started． The skin lesions had resolved six months
later． Psoriasifbrm skin lesions induced by TNF-α antagonists are rare，but pediatricians should remain aware
of the possibility of psoriasis arising in JIA patients treated with TNF-α antagonists．
