Inflammatory Skin Diseases PDF

Inflammatory skin diseases Function barrier for microorganisms limit water loss thermoregulation immune regulation protection against ultraviolet light Histology Epidermis composed of a multilayered sheet of keratin-producing cells keratinocytes Histology Histology Histology Melanocytes a...

Inflammatory skin diseases Function barrier for microorganisms limit water loss thermoregulation immune regulation protection against ultraviolet light Histology Epidermis composed of a multilayered sheet of keratin-producing cells keratinocytes Histology Histology Histology Melanocytes are dendritic cells of neural crest origin Langerhans cells carry antigenic cargo to regional lymph nodes and initiate immune responses Merkel cells are specialized cells in the skin that are important for proper neural encoding of light touch stimuli Nomenclature of skin lesions-Macroscopic Excoriation: Traumatic lesion breaking the epidermis and causing a raw linear area (i.e., deep scratch); often self-inflicted Nomenclature of skin lesions-Macroscopic Lichenification: Thickened, rough skin usually the result of repeated rubbing lichen on a rock Nomenclature of skin lesions-Macroscopic Macule, patch: Circumscribed, flat lesion distinguished from surrounding skin by color. macule ≤ 5 mm patch > 5 mm Nomenclature of skin lesions-Macroscopic Papule, nodule: Elevated dome-shaped or flat-topped lesion papule ≤ 5 mm nodule > 5 mm Nomenclature of skin lesions-Macroscopic Plaque: Elevated flat-topped lesion, usually greater than 5 mm in diameter (may be formed by coalescence of papules) Scale: Dry, horny, plate like excrescence; usually the result of imperfect cornification Nomenclature of skin lesions-Macroscopic Pustule: Discrete, pus-filled, raised lesion Wheal: Itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema Nomenclature of skin lesions-Macroscopic Vesicle, bulla, blister: Fluid-filled raised lesion. Blister is the common term for both lesions. vesicle ≤ 5 mm bulla > 5 mm Nomenclature of skin lesions-Microscopic Acanthosis: Diffuse epidermal hyperplasia Hyperkeratosis: Thickening of the stratum corneum Parakeratosis: nuclei (+) Orthokeratosis: nuclei (-) Nomenclature of skin lesions-Microscopic Dyskeratosis: Abnormal, premature keratinization within cells below the stratum granulosum Nomenclature of skin lesions-Microscopic Spongiosis: Intercellular edema of the epidermis Acantholysis: Loss of cohesion between keratinocytes