•Extensive ballooning degeneration of the upper epidermis where the keratinocytes show pale cytoplasm and pyknotic nuclei
•Confluent parakeratosis
•Confluent and focal keratinocytic necrosis
•Intraepidermal vesiculation
•Psoriasiform hyperplasia of the epidermis
•Edema of the papillary dermis
•A patchy lichenoid infiltrate consisting of lymphocytes, histiocytes, eosinophils and some neutrophils
•Marked extravasation of red blood cells