Three Cases of Generalized Pustular Psoriasis Successfully Treated with an Infliximab Biosimilar

<p>Case 1 is a 54-year-old female. Erythema appeared on her right upper arm and left wrist 10 days before the first visit. As the erythema had spread to her entire body and pustules had appeared, she was referred to our hospital. Her drug history raised suspicions of acute generalized exanthematous pustulosis, but systemic corticosteroid therapy was ineffective. Her poor response to corticosteroid therapy and the finding of an IL36RN gene mutation in a genetic test led to a decision to treat her for generalized pustular psoriasis. Her symptoms were improved after treatment with an infliximab biosimilar. Case 2 is a 36-year-old female. She developed psoriasis vulgaris at about age 20, and she had been treated by a local dermatologist since then. Erythema with small pustules appeared 10 months before her first visit, and she had started taking apremilast 5 months before that visit. Her symptoms were not improved, and she was referred to our hospital. She was given a diagnosis of generalized pustular psoriasis and treated with granulocyte and monocyte adsorptions plus an infliximab biosimilar, and her symptoms were improved. Case 3 is a 66-year-old man. At about age 15, he developed erythema and scales on his head. At about age 33, he developed a fever, and erythema with pustules appeared on his trunk. He had a diagnosis of generalized pustular psoriasis by a local dermatologist. He started taking etretinate, and his symptoms were improved. However, 1 month before the first visit, his erythema with pustules recurred and he was referred to our hospital. His symptoms improved after treatment with an infliximab biosimilar. Infliximab biosimilar drugs are approved for psoriasis by extrapolated drug reaction, and their efficacy and safety for generalized pustular psoriasis in Japan are unclear. In our hospital, an infliximab biosimilar was effective in all three cases, although the combination of an infliximab biosimilar with granulocyte and monocyte adsorptions or etretinate may contribute to that results. Skin Research, 19 :190-196, 2020 </p>