Homeostatic Imbalances The Skin Homeostatic Imbalances

Tattoos Needle is used to deposit pigment within the dermis Risks: One ugly tattoo Dyes w/cancer causing agents Hepatitis C Removal: Dermabrasion, cryosurgery, caustic chemicals, laser based technology

Excessive Sun exposure Damages skin Elastic fibers clump -> leathery skin Chance for herpes (aka cold sore) increases Alter DNA of skin cells -> skin cancer inc melanin in black ppl dec chance for skin cancer

Decubitus Ulcer Restriction of normal blood supply to skin Causes cell death Occurs often in bedridden patients who are no turned regularly or who are dragged or pulled repeatedly across bed Blood supply restricted -> blanching Skin reddens when pressure released Cracks appear in skin @ compressed areas

Infections and Allergies Athlete’s Foot Itchy, red, peeling between toes Fungal infection: fungus grows on or in the top layer of the skin Easily transferred Can be caught walking near swimming pools and lockers

Infections and Allergies Boils and carbuncles Boils: inflammation of hair follicles and sebaceous glands Carbuncles: boils caused by bacterial infection

Infections and Allergies Cold Sores Small, fluid-filled blisters Itch and sting Caused by herpes simplex infection Virus localizes in cutaneous nerve Dormant until activated by emotional upset, fever, or UV

Infections and Allergies Contact dermatitis Itching, redness, swelling of skin, blistering Caused by exposure of skin to chemicals i.e. poison ivy

Infections and Allergies Impetigo Pink, water-filled, raised lesions Develops yellow crust and ruptures Caused by staphylococcus infection Common in elementary children

Infections and Allergies Psoriasis Reddened epidermal lesion Dry, silvery scales May be disfiguring

Burns Tissue damage and cell death caused by intense heat, electricity, UV, or chemicals Two life-threatening problems: Body loses supply of fluids containing proteins and electrolytes Dehydration and electrolyte loss = shutdown of kidneys and circulatory shock Lost fluids must be replaced immediately!

Burns Rule of nines: Infection leading cause of death in burn victims Divides body into 11 area, each accounting for 9% of total body surface (plus 1% for genital) Infection leading cause of death in burn victims Burned skin sterile for 24 hours Patient’s immune system depressed

Burns First degree Only epidermis damaged Area red and swollen Not serious Heals in two to three days i.e. sunburn

Burns Second degree Injury to epidermis and upper dermis Red, painful, and blisters present Enough epithelial present for regeneration No permanent scars result if taken care of First and second degree burns are called partial-thickness burns

Burns Third degree Destroys entire thickness of skin aka full-thickness burn Burned area is blanched or blackened Nerve endings destroyed = no pain Regeneration not painful Skin grafting

Fourth Degree Burn a burn that extends deeply into the subcutaneous tissue, completely destroying the skin, subcutaneous tendons, underlying tendons, involving muscle, fascia, or bone

Burns Considered critical if: 25% has second degree burns 10% has third degree burns Third degree burns of face, hands, or feet Dangerous because burned respiratory passageways Swells and causes suffocation

Skin Cancer Single most common type of cancer in humans Most important risk factor is UV radiation

Skin Cancer Basal cell carcinoma Least malignant Most common type (usu. On face) Cells in stratum basale cannot form keratin and no longer honors boundary between epidermis and dermis Appears shiny, dome-shaped nodules that develop an ulcer Slow-growing curable

Skin Cancer Squamous Cell Carcinoma Lesion appears scaly, reddened papules Gradually forms ulcer Usu on scalp, ears, dorsum of hands, lower lip Grows rapidly and into lymph nodes if not removed Curable surgically or w/radiation therapy

Skin Cancer Malignant melanoma Cancer of melanocytes Accounts for 5% of skin cancers Usu. Appears as spreading brown to black patch Grows into lymph and blood vessels Survival is 50% Treatment is wide surgical excision with immunotherapy

Malignant melanoma Use ABCD on new moles or pigmented spots to recognize Asymmetry: two sides of spot do not match Border irregularity: borders of lesion are not smooth and have indentations Color: spot contains areas of different colors Diameter: spot is larger than 6 mm in diameter

AGE Newborn: skin is thin and blood vessels are visible Skin thickens with age Adolescence: skin and hair become oily Adulthood (twenties and thirties): skin reaches optimal appearance Environmental affects: abrasion, chemicals, wind, sun, and other irritants clog pores with pollutants and bacteria dermatitis (skin inflammation), pimples, scales occur

FRECKLES: Concentration of Melanin in a certain area Old Age: subcutaneous tissue decreases, skin is drier, skin thins, decreased elasticity FRECKLES: Concentration of Melanin in a certain area HAIR: By 50, # of follicles dec by 1/3 Bald men have hair in “bald areas” degenerated follicles develop colorless and tiny hair Graying: dec in amount of melanin deposited in the hair emotional crisis, anxiety, protein deficiency, chemotherapy, radiation, excessive vitamin A, fungal diseases, genetics