Mod 11 Skin Flashcards
Psoriasis
genetic, chronic thickening of epidermis. presents as silver-white scales over red, thickened plaques. Can be associated with disabling arthritis of hands and fingers.
T-cell mediated autoimmune response to unknown antigen.
Lesions bleed when scales are removed (Auspitz sign)
Contact dermatitis
delayed hypersensitivity reaction to metals, chemicals, drugs, poison ivy, typically days after skin contact with allergen.
Urticaria
hives - caused by allergy, severe cases including angioedema. Lesions (wheals) appear suddenly on skin and mucous membranes. Blanch with pressure. Caused by release of histamine by mast cells.
Seborrheic dermatitis
Inflammation of the skin caused by excessive secretions of the sebaceous glands.
Dandruff and red lesions appear to be greasy, inflamed, and itchy
Eczema aka atopic dermatitis
elevated immunoglobulin IgE levels, as it is associated with allergy or type I hypersensitivity reactions
Actinic Keratoses (precancer)
Patho: Premalignant lesion on skin that is damaged by UV rays surrounding tissues are red and may show telangiectasia (branches of delicate capillaries. Can progress to squamous cell carcinoma.
Eti: Common in fair skinned people
CM: patches of rough, scaly, red plaques.
Lentigo (precancer)
Patho: Large pigmented spots, called age spots, appear on fair, sun-damaged areas of the skin, usually on the hands, forearms, and face. Can grow to a size of 5 cm. Can progress to malignant melanoma.
CM: Lentigos, premalignant skin lesions, usually appear as brown spots on sun-exposed areas. Overtime lesions become raised and wartlike.
Melanoma
Patho: radial growth phase, malignant cells grow in a radial, spreading manner in the epidermis. With time, melanomas progress to the vertical growth phase, where malignant cells invade deep into the dermis and are able to metastasize.
Eti: Gene 9p21 linked to melanoma. Melanoma originates in melanocytes (cells that produce pigment melanin). Penetrates deep into the skin, invades the blood and lymphatic vessels, and then metastasizes throughout the body.
CM: (common warning sign is change)
A: Asymmetry: one half unlike the other
B: Border: an irregular, scalloped, or poorly defined border
C: Color: varied from one area to another; shades of tan, brown, and black; sometimes white, red, or blue
D: Diameter: usually larger than 6 mm, or the size of a pencil eraser, when diagnosed, but they can be smaller
E: Evolving: a mole or skin lesion that looks different from the rest or is changing in size, shape, or color
Diagnosis: Diagnosis of sus lesion
Melanoma Staging
Stage 0: Melanoma that is confined to the epidermis
Stage I-II: confined to the skin but has increasing thickness; skin may be intact or ulcerated (top layer of skin is absent)
Stage III: has spread to a nearby lymph node and is found in increasing amounts in one or more lymph nodes
Stage IV: spread to internal organs, beyond the closest lymph nodes to other lymph nodes, or to areas of the skin far from the original tumor
Basal Cell
90% of all skin cancers. Rarely metastasize but can grow deeply and invade surrounding tissue. Face is most common location. Typically begins as a small, dome shaped bump covered by small, superficial blood vessels. Often shiny and translucent, “pearly”
Squamous cells
Appears as red, crusted, scaly patch on the skin, as a nonhealing ulcer or as a firm, red nodule. Those on lip or ear are particularly aggressive. If left untreated, have a high risk of metastasis to lymph nodes and other internal organs.
