A 74-year-old man was admitted for diffuse skin lesions since several months. His past medical history included type 2 diabetes, hypertension, chronic heart failure and chronic kidney disease. Skin lesions were first diagnosed as severe psoriasis and treated with Psoralen and Ultraviolet A (PUVA), oral steroids and methotrexate. Despite this treatment, the patient state worsened and lesions became more extensive (Fig. 1A-B), painfull and bleeding easily. Skin biopsies were then performed. What is the diagnosis?
