Histopathological study of the patient’s right forearm (Case 1). Erosions are seen on some parts of the epidermis (A). Inflammatory infiltration of neutrophils and lymphocytes, extravasation of red blood cells, and nuclear debris (B) and inflammatory infiltration of eosinophils (C) in the perivascular area. Fibrinoid necrosis is also noted (D). (A) Haematoxylin and eosin staining, ×40. (B–D) Haematoxylin and eosin staining, ×400.