Lesions heal by primary intention and without scarring. Intraepithelial necrosis or inflammation causes exfoliation. Alternatively, erosions may result from the disruption of superficial pustules, vesicles and bullae. The shape and character of the lesions may again give clues to the type of lesion that preceded them. Erosions evolving from pustules leave round to oval erosions often surrounded by an epidermal collarette.
Excoriations are often linear or angular and associated with haemorrhagic crusts.
Both ulcers and especially erosions may be covered with crusts. These consist of any combination of serum, necrotic tissue, scale, blood or inflammatory cells especially leucocytes. Crusts may become extremely thickened with chronicity to produce eschar. This material delays normal granulation, commonly cracks and fissures thus perpetuating the damage.