Dermatology Flashcards
Primary functions of the skin
protect body from microorganisms, control body heat, eliminate waste through perspiration, prevent injury to the core. Peripheral receptors alert the body to pain, temperature changes and touch
Three layers of the skin
Epidermis, Dermis, and Hypodermis
Macule
Skin color change without elevation. Ex - freckle, petechia Patch if greater than 1cm.
Papule
Elevated solid lesion less than 1cm, varying in color. Ex - warts
Plaque
Raised, flat lesion formed from merging papules or nodules
Nodule
Larger than a papule, extends into the dermis deeper. Raised and solid. Large nodule is a tumor
Wheal
fleeting skin elevation, irregular shape d/t edema ex - mosquito bite
Vesicle
Elevated, sharply defined margins,
Bulla
Larger than 1cm fluid filled elevated. Ex - partial thickness burn
Cyst
Elevated thick walled lesion containing fluid or a semi solid matter
Pustule
Elevated lesion less than 1cm with purulent material. Larger than 1cm is a boil, abscess or furuncles
Scale
Dried fragment of sloughed epidermal cells, irregular in shape and size. White, yellow or silver. ex - dandruff, dry skin, psoriasis
Erosion
Moist, demarcated, depressed area with partial or full thickness loss of epidermis. Dermis intact. Ex - ruptured chicken pox
Deep Ulcer
All of epidermis and all or part of the dermis is lost. Irregular, exudative, depressed. From trauma like pressure ulcer
Lichenification
Epidermal thickening causing elevated plaque with accentuated skin markings from repeated scratching or injury like in chronic atopic dermatitis
Excoriation
superficial linear abrasion of epidermis, visible sign of itching
Fissure
deep split from epidermis to dermis ex - tinea pedis
Keloid
irregularly shaped elevated progressively enlarged scar, extending beyond boundaries of the wound, caused by excessive collagen formation
Derm evaluation
by morphology, region or diff dx
most frequent cause of malpractice in derm
failure to dx
inspection of the skin
note color, moisture, temp, texture, mobility, turgor, lesions
color changes in skin
increase pigmentation, decreased pigmentation, redness, pallor, cyanosis, yellow
red color of oxyhemoglobin best assessed
fingertips, lips, mucus membranes. dark skinned: palms and soles
central cyanosis
lips, oral mucosa and tongue
jaundice
sclera
ease in which skin moves up/skin returns to normal
mobility/turgor
technique of exam for lesions
characteristics of anatomic location, patterns and shapes, type of lesion, color. To have a dx: Determine the type of lesion, location and distribution along with the patient’s h&p.
inspect hair
inspect and palpate, note quality and distribution, texture, any infestations
inspect nails
color and shape, lesions, longitudinal bands of pigment may be common in people with darker skin
three layers of skin starting from the inside going out
subcutaneous tissue, dermis and epidermis
epidermal appendages
hair, sebaceous glands, sweat glands (eccine and apocrine), nails
epidermis
thin but tough - DEVOID of blood vessels. tightly bound cells that are replaced every 4 weeks. STRATIFIED zones starting wit hthe stratum germinativum “basal cells”, blend of keratin and melanin
dermis
inner supportive layer, connective tissue collagen, tough - helps to resist tearing, elastic with resilient capacity, placement of the nerves, sensory receptors, BLOOD VESSELS and lymphatics
subcutaneous layer
adipose tissue - fat, stores the fat for energy, provides insulation, soft cushioning effect
four appendages: 1) hair
VESTIGIAL: no longer needed for protection from cold or trauma, threads of keratin, held in place from arrector pili which contract and elevate the hair - goosebumps, two types: fine/faint = vellus, course/thick = terminal