Skin anatomy: Cellulitis, erysipelas, and skin abscess

Cellulitis and erysipelas manifest as areas of skin erythema, edema, and warmth; they develop as a result of bacterial entry via breaches in the skin barrier. Cellulitis involves the deeper dermis and subcutaneous fat; in contrast, erysipelas involves the upper dermis, and there is clear demarcation between involved and uninvolved tissue. A skin abscess is a collection of pus within the dermis or subcutaneous space.