Erosion is focal loss of part or all of the epidermis. It often occurs with herpesviruses and pemphigus. Ulcers are focal loss of the epidermis and at least part of the dermis. When ulcers result from physical trauma or acute bacterial infection, the cause usually is apparent. Less obvious causes include chronic bacterial and fungal infections, various peripheral vascular diseases and neuropathies, systemic scleroderma, and tumors.
Excoriation is a linear or hollowed-out crusted area caused by scratching, rubbing, or picking.
Lichenification is a thickened skin area with accentuated skin markings. Atrophy manifests as paper-thin, wrinkled skin. It occurs in the aged, in discoid LE, after long-term use of topical potent corticosteroids, and sometimes after burns. Scars are areas of fibrous tissue that replace normal skin after destruction of some of the dermis. All rights reserved.