Hyperpigmentation Usually a consequence of melanin excess, either increased numbers of melanocytes, or increased production of melanin and melanin deposition in the basal epithelium. This is superficial loss of epidermis often due to self trauma secondary to pruritus. They are often linear. Erosion Loss of epidermis with the basal layer remaining intact. Often occur when intraepidermal vesicles and bullae rupture.
Healing occurs without scar formation.
Ulcer Loss of epidermis with loss of integrity of the basement membrane. The thickening of the epidermis with accentuation of normal skin folds and markings. It is often accompanied by hyperpigmentation. It is a response to chronic trauma or inflammation . Scar Occurs when the basal layer of the epidermis has been breached and the underlying dermis is damaged.