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166 Cards in this Set
- Front
- Back
dematology
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study of the integument:
skin hair nails mucous membrances |
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Functions of the skin
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-protect against microbial and foreign invasion and minor physical trauma
-provide mechanial barrier against body fluid loss -regulates body temperature -provides sensory perception via free nerve endings and specialized receptors -produces vitamin D from precursors in skin -contributes to BP regulation through constriction of skin and vessels -excretion of metabolites -express emotions (blushing) |
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Layers of epidermis
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1. stratum corneum
2. cellular stratum |
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stratum corneum
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-1st layer of epidermis
-dead layer -cornified cells, "horny layer" -tightly packed dead squamous cells -contains keratin (the waterproofing protein) -keeps skin hyrated |
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layers of cellular stratum (of epidermis)
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1. stratum granulosum
2. stratum spinosum 3. stratum basale |
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Stratum granulosum
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granular cells
-contains 3- rows of granular cells (flattened cells whose cytoplasm contains small granules) -granules are proteins that are in the process of transforming into the waterproofing protein keratin -contains glycolipids and a thickening of the membrane. |
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Stratum spinosum
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-prickle or spinous cells
-multi-layered arrangement of cuboidal cells -adjacent cells are joined by desmosomes giving them a spiny appearance -cells actively synthesize intermediate filaments composed of keratin -intermediate filaments are anchored to the desmosomes joining adjacent cells to provide structural support, helping the skin resist abrasion |
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Stratum basale
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-germinativum
-contains keratinocytes and melanocytes -lies just above dermis -single layer of tall, simple columnar epithelial cells lying on a basement membrane -cells undergo rapid cell division to replenish the regular loss of skin by shedding from the surface |
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Basement membrane
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connnects epidermis to the dermis
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Dermis
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-provides nutrition for the epidermis by means of penetrating papillae
-contains: -connective tissue (elastin, collagen, reticulin fibers) -sebaceous glands -blood vessels -sensory nerve fibers -autonomic motor fibers |
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Hypodermis
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-subcutaneous layer
-loose connective tissue filled with fatty cells -sweat glands -some hair follicles |
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Eccrine sweat glands
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-distibuted over most of body
-open directly to surface of skin -regulated body temp through water secretion -produce sweat composed chiefly of water |
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miliaria
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pathology of eccrine glands
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apocrine sweat glands
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-inactive until puberty
-larger and deeper than eccrine -found in axilla, anogenital region, areola, nipple, eyelids, external ear -secretion stimulated by emotional stress -produce sweat that contains fatty materials -reponsible for body odor |
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What causes body odor
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bacterial decomposition of apocrine sweat (bacteria breaks down organic compounds in the sweat)
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hidranetitis suppurativa
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pathology of apocrine glands
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sebaceous glands
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-stimulated by sex hormones
-secrete lipid rich sebum to keep skin and hair lubricated -sebum moves to skin through hair follicles -NONE on palms or soles |
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Acne
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pathology of sebaceous glands
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hair follicles consist of...
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-root, shaft, follicle
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nutrients for hair follicles provided by the...
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papilla
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Determination of skin pigments
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-melanin (brown)
-carotene (golden yellow-orange) -oxyhemoglobin (bright red) -deoxyhemoglobin (dark blue) |
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Skin type I
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-always burns, never tans
-severe sun damage can appear as permanent freckling, especially on shoulders, face, arms -red hair and green eyes are associated with this skin type |
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Skin type II
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-frequently burns, sometimes tans
-fair hair and blue eyes |
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Skin type III
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-frequently tans, sometimes burns
-darker hair and eyes -sun protection is required to avoid sunburn and prevent premature aging of the skin |
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Skin type IV
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-always tans, never burns
-tolerant skin when exposed to sunshine -dark brown hair and eyes - non-melanoma skin CA may develop after yrs of sun exposure |
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Skin type V & VI
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-asian and black skin
-non-melanoma skin CA may also develop following yrs of sun exposure |
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What light rays are useful for skin inspection?
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-natural sunlight is best
-combination of incandescent and fluorescent is next best |
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Abnormal skin colors
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-pallor (pale)
-cyanosis (blue) -erythema (red) -jaundice/sclera icterus (yellow) -ashen/dusky (gray) |
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Acrocyanosis
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cyanosis in palms and soles of feet
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peripheral cyanosis
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cyanosis in arms and legs
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central cyanosis
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cyanosis in mouth and tongue
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Vellus hair
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short
fine soft inconscpicious nonpigmented |
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Terminal hair
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conspicious
thicker coarse usually pigmented |
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Life cycle of hair
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1. anagen (growth)
2. catagen (atrophy) 3. telogen (rest) 4. shed (loss) |
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Nail composition
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epidermal cells converted to hard plates of karatin
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Nail growth
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0.1 mm/day = 1 cm/100 days
-finger nails - 3 months to grow out -toe nails - 6 months to grow out |
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Parts of the Nail
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-nail bed
-lunula -eponychium (cuticle) -paronychium (lateral sides) |
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Changes in androgen stimulate...
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-increases terminal hairs on face
-appearance of axillary hair -increased truncal and body hair (M>F) |
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Changes in apocrine glands with adolescence
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-enlarge
-become active causing axillary sweating and body odor |
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Changes in sebaceous glands with adolescence
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-increase sebum production (response to hormones, mainly androgen) causing oily skin and acne
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Changes in Eldery
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-dec skin turgor
-dec vascularity of dermis -skin thins and becomes more fragile -furrowing and thickening of skin -nails lose luster and yellow -hair loses pigmentation and begins to thin |
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Derm Hx questions
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-how long have you had it?
-does it itch/burn/hurt? -how and where did it start? -has it changed? how? -any meds? -exposed to new substances/irritating agents at home or work? (soaps, detergents, fabric softeners, pets, cleaners, foods, clothing) -tried anything for it? -allergies? -ongoing systemic illness? -Previous hx of this? diagnoisis? tx? -friends/family with this? |
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Glass slide
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equipment used for blanching
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Woods lamp
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equipment used to illuminate fungus (like a blacklight)
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Diagnostics for derm
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-fungal scraping with KOH prep (kills everything but the fungus)
-fungal culture -Tzanck smear (Herpes) -scabies prep (Scabies) -Alergy skin testing (patch tetsting and prick testing) |
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Primary lesion
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lesions that occur as the INITIAL spontaneous manifestation of an underlying pathologic process
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Secondary lesion
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lesions that result from later evolution of or trauma to a primary lesion
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Examples of primary skin lesions
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-macule
-patch -papule -plaque -wheal -nodule -tumor -pustule -cyst -vescicle -bulla |
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Macule
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-flat, nonpalpable
-circumscribed -less than 1 cm in diameter -brown, red, purple, white, tan |
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Examples of macules
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-freckles
-flat moles -solar lentigines -tinea versicolor |
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Patch
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-flat, nonpalpable
-irregular in shape -greater than 1 cm in diameter |
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Examples of patches
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-vertiligo
-congential melanocyte nevus -port wine stains |
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Papule
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-elevated, palpable
-firm, circumscribed -less than 1 cm in diameter -brown, red, pink, tan, or bluish red |
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Examples of papules
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-warts
-malignant melanoma -lichen planus -pigmented nevi |
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Plaque
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-elevated, palpable
-firm, rough -greater than 1 cm in diameter |
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Plaque examples
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-psoriasis
-seborrheic and actinic keratoses |
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Wheal
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-elevated, palpable
-irregular shaped area of cutaneous edema -solid -transient, changing -variable diameter -pale pink with lighter center |
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Wheal examples
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-uticaria
-insect bites |
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Nodule
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-elevated, palpable
-firm, circumscribed -deeper in dermis than papule -1-2 cm in diameter |
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Nodule examples
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-erythema nodosum
-keratoacanthoma -lipomas -cystic basal cell carninoma -kaposi's sarcoma |
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Tumor
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-elevated, palpable
-solid -may or may not be clearly demarcated -greater than 2 cm in diameter -may or may not vary from skin color |
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Tumor examples
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-neoplasm
-turban tumor |
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Vesicle
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-elevate, palpable
-circumscribed -superficial -filled with serous fluid (clear fluid) -less than 1 cm in diameter |
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Vesicle examples
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-blisters
-varicella -eczema -herpeticum -herpes zoster |
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Bulla
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-elevated, palpable
-vesicle greater than 1 cm in diameter |
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Bulla examples
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-blisters (giant blisters)
-pemphigus vulgaris |
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Pustule
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-elevated, palpable
-superficial -similar to vesicle but filled with purulent fluid (white fluid) |
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Pustule Examples
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-impetigo
-acne -folliculitis |
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Cyst
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-elevated, palpable
-circumscribed, encapsulated -filled with liquid or semi-solid material |
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Cyst examples
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-epidermoid cyst
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Examples of Secondary lesions
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-scale
-crust -lichenification -scar -keloid -excoriation -fissure -erosion -ulcer |
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Scale
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-heaped up keratonized cells
-flaky exfoliation -irregular -thick or thin -dry or oily -varies in size -silver, white, or tan color |
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Scale examples
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-psoriasis (white/silver)
-exfolaitive dermatitis |
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Crust
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-dried serum
-blood or purulent exudate -slightly elevated -size varies -brown, red, black, tan, or straw color |
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Crust Examples
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-scab on abrasion
-impetigo -eczema |
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Lichenification
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-rough, thickened epidermis
-accentuated skin markings caused by rubbing or iiritation -often involves flexor aspect of extremity -often d/t scratching |
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Lichenification example
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-chronic dermatitis
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Scar
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-thin the thick fibrous tissue replacing injured dermis
-irregular -pink, red, or white -may be atrophic or hypertorphic |
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Keloid
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-progressively enlarging scar
-irregularly shaped -elevated, growing beyond boundaries of the wound -caused by excessive collagen formation during healing |
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Excoriation
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-loss of epidermis
-linear or hollowed out crusted area -dermis exposed |
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Excoriation examples
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-abrasion, scratch
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Fissure
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-linear crack or break from epidermis to dermis
-small, deep -white, pink, and red |
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Fissure examples
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-athletes foot
-cheilosis |
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Erosion
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-loss of all or part of epidermis
-depressed -moist, glisterning -follows rupture of vesicle or bulla -larger than a fissure |
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Erosion example
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-pemphigus vulgaris
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Ulcer
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-loss of epidermis and dermis
-concave -varies in size -exudate -red or reddish blue -deeper than an erosion |
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Ulcer examples
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-decubiti
-stasis ulcers -radiation ulcers |
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Atrophy
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-thinning of skin surface
-loss of skin markings -skin translucent and paper-like |
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Atrophy examples
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-striae
-aged skin -stretch marks |
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Vascular Skin Lesion
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-difference in whether they blanch or not
-examples: ecchymosis, petechiae, purpura, capillary hamingioma, telangiectasia, venous star, spider angioma |
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Ecchymoses
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-red-purple nonblanchable discoloration
-variable size -caused by vascular wall destruction, trauma, vasculitis |
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Causes of ecchymoses
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-vascular wall destruction
-trauma -vasculitis |
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Petechiae
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-red-purple nonblanchable discoloration
-less than 0.5 cm in diameter (pinpoint size) -usually linked to blood disorder |
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Cause of petechiae
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-intravascular defects
-infection -meningococcemia |
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Purpura
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-red-purple nonblanchable discoloration
-usually spot-like, round -greater than 0.5 cm in diameter |
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Cause of purpura
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-intravascualr defect
-infection |
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Capillary hemangioma (Nevus flammeus)
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-red, irregular macular patches
-"cherry hamangioma" -caused by dilation of dermal capillaries |
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Cause of capillary hemangioma
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-dilation of dermal capillaries
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Telangiectasia
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-fine, irregular lines
-caused by dilation of capillaries |
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Causes of telangiectasia
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-dilation of capillaries
-seen in autoimmune dz (lupus) |
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Venous Star
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-bluish spider
-linear or irregular shaped -does NOT blanch -caused by increase pressure in superficial veins |
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Causes of venous star
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-increased pressure in superficial veins
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Spider Angioma
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-red, central body with radiating spider-like legs
-blanched with pressure to central body |
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Causes of spider angioma
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-liver dz (often in alcoholics)
-vitamin B deficiency -idiopathic |
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Primary union
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-mechanically close wound
-healing by first intention -used for clean, incised wounds where edges are in close opposition |
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Secondary union
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-let the wound close itself
Used when: -unable to achieve opposition of wound edges -foreign material is present -extensive necrosis is present -infection is present |
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Characteristics used to categorize skin lesions
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-distribution
-pigmentation -shape and pattern -consistency -symmetry -margins/borders |
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Distribution
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-localized (extensor surfaces, sunexposed areas, unexposed areas, intertriginal areas)
-regional -generalized (often viral or drug rxn) |
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Pigmentation
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-hetergneous vs homogenous
-color |
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Shape
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-linear
-round or discoid -oval -annula (round with clear center) -polycyclic (multi-ringed) -arciform (incomplete ring) -grouped -iris or target lesions -reticulate (net/mesh pattern) -dermatomal -descrete vs confluent (blend together) |
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pattern
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-smooth
-rough -flat topped -pointed -dome shaped and umbilicated (central depression) |
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consistency
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-soft (more epidermis)
-firm (deeper, into dermis) -hard (often dead tissue) |
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Symmetry
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-symmetrical
-asymmetrical |
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margins
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-demarcated (circumscribed if dealing with round border)
-irregular |
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Therapeutic rules for dermatology
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1.If it is wet, make it dry
2.if it is dry, make it wet 3. If you don't know what it is..consider a steroid cream 4. start with low potency agent first and work your way up 5. remove allergens from environment when possible (pets, soaps, perfumes) 6. know when to refer 7. DO NO HARM |
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Corticosteroids
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-fluorinated vs unfluorinated
-potency -ointment vs cream -system corticosteroids are sometimes required (prednisone, depromedrol) |
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fluorinated vs unfluorinated
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fluorinated are higher potency
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Ointment vs Cream
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Ointments are usually stronger than creams
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Potency
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low, medium, high, and superhigh potency groups
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Emollients for Dry Skin
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-best applied after bath or shower
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Examples of emmollients
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-petrolatum (vaseline)
-mineral oil -creams (sucerin) -lotions (lubriderm) -lac-hydrin (lactate) - in cream or lotion |
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Soaps should be limited to...
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axillae, groin, and feet in pt with dry skin!!
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Drying agents for weepy dermatitis
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-water
-aluminum salts -colloidal oatmeal (aveeno) -shake lotions (starch or calamine) -powders |
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Antipruritics
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-lotions (0.5% camphor and menthal)
-pramoxine HCl cream/lotion -corticsteroids -antihistamines -tricyclic antidepressants -psychotrophic meds |
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What works best as an antipruritic?
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sedating antihistamine
|
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Examples of sedating antihistamine
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-benadryl (diphenhydramine)
-atarax (hydroxizine) |
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Examples of non-sedating antihistamines
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-claritin
-allegra |
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Examples of mildly sedating antihistamines
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-zyrtec
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Examples tricyclic antidepressants
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-doxepin (sinequan)
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UVB vs UVA
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UVB:
-effects more superficial layers -causes sunburn -causes majority of skin CA (primarily basal and squamous cell CA) UVA -penetrates deeper -responsible for aging process -helps with mutation for melanoma -most tanning beds BOTH -cause retinal damage -contribute to aging |
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SPF
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-sun protection factor
-15 or above (15 is basically max effect) |
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PABA vs PABA free
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Para-aminobenzoic acid
PABA - absorbs UV light, helps prevent sun damage BUT frequent cause of allergic rxn and stains clothing |
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Topical antifungals
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-imidazoles
-clotrimazole |
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Sunscreen should be applied...
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-1 hour before exposure and q4 hrs thereafter
|
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Topical antibiotics
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-bacitracin
-neomycin (most sensitizing so many pt are allergic!!) -polymycin -sulfa preps -bactroban |
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Vehicles
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-powders
-liquids -gels -creams -ointments |
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Liquids
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-lotions
-tinctures (more concentrated) -sprays -aerosoles |
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Ointments (types)
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-soluble in water
-emulsify with water -insoluble with water -pastes |
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Topical anesthetics
|
-viscous lidocaine
|
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Topical Scabicides
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(antiparasitics - used to kill scabies)
-permethrin -lindane (kwell) |
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Powders
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-promote drying by inc surface area
-reduce moisture, maceration, and friction -useful in intertriginous areas) |
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ointments
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-contain little water, if any
-feel greasy -used to lubricate -preferred for lesions c thick crusts, lichenification, heaped up scales -often more potent than creams |
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creams
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-semisolid emulsions of oils and water
|
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lotions
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-most are water based emulsions
-cools and DRY acute inflammatory and exudative lesions |
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Types of Dressings
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-open wet (wet to dry)
-closed wet -occulsive |
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occulsive therapy
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-covering with nonporous dressing
-increases absorption and effectiveness |
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Complications of derm therapy
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-allergic rxn
-irritation -hypopigmentation |
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Allergic rxn d/t derm therapy
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-neomycin
-corticosteroids -bandage/tape rashed |
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irritation d/t derm therapy
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-lindane (kwell)
-soaps (especially antispetic and fragrant soaps) -podophyllum resin |
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Hypopigmentation d/t derm therapy
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-d/t use of corticosteroids
-greater in genital area -greater with long term use -irreversible -more common in skin type IV and V |
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Greatest absoption in which areas
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-face
-genital area -mucous membranes -broken skin -under occlusive dressing |
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When to use lower potency
|
-larger surface area
-prolonged use |
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Absorption in children vs adults
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Children absorb 3x more than adults
|
|
Lindane contraindicated in...
|
-children
-pregnancy woman |
|
Inquire about pregnancy when using
|
-podophyllum
-accutane |
|
Therapeutic techniques
|
-skin biopsy
-curettage -electrosurgery -cryosurgery (liquid nitrogen) |
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types of Skin biopsy
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-shave biopsy (partial thickness)
-punch biopsy (full thickness) -elliptical excisonal biopsy |
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Shave biopsy shoud not be used with...
|
melanomas
|
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What is the difference between a fluorinated and unfluorinated corticosteroid?
|
-fluorination (chemical modification) generally enhance both anti-inflammatory activity and increase the likelihood of adverse effects
|
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Basic effects of corticosteroids?
|
-anti-inflammatory
-anti-pruritic -vasocontriction |
|
Science behind corticosteroid effects?
|
-corticosteroids are thought to induce phospholipase A2 inhibitor proteins, preventing arachidonic acid release & biosynthesis of potent mediators of inflammation
|
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Why is nonfluoronated corticosteroids preferred for facial dermatosses?
|
nonfluorinated, does not usually induce facial telangiectasia, perioral dermatitis, atrophy, or striae
|
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emollients
|
skin softeners
|
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Gels vs Creams
|
-more drying than creams
-less potent than creams |
|
astringents
|
-drying agents that precipitate protein
-skrink and contract skin |
|
relative potency between lotions, ointments, and creams
|
-ointments (most potent)
-cream -lotion (least potent) |