Module 1: Dermatology - Surface and Depth Changes

Scale

Fine or thick, dry or greasy flakes on the skin surface (example: psoriasis, seborrheic dermatitis)

Lichenification

Thickened skin with exaggerated skin lines and leathery texture caused by chronic rubbing or scratching)

Excoriation

Linear or punctate superficial erosion (caused by fingernail scratching)

Fissure

Linear crack or split extending from epidermis into dermis; often painful (example: hand eczema, xerosis)

Erosion

Loss of epidermis only; moist, shallow, glistening lesion that heals without scar because dermis remains intact

Ulcer

Full-thickness epidermal loss with involvement of dermis; heals with scarring