Diagnosing Skin Conditions

how many layers are there of the epidermis

5 layers, cellular strata

what is the outermost layer of the epidermis

stratum corneum

what types of cells are in the epidermis

keratinocytes

melanocytes

langerhan’s cells

merkel cells

what does the dermis contain

blood and lymph vessels

connective fibers (collagen, elastin)

nerve fibers

hair follicles

what does the subcutaneous tissue contain

adipose tissue

what are the appendages of the skin

eccrine sweat glands

apocrine sweat glands

sebaceous glands

what is the function of the skin

protection against foreign substance invasions and trauma

retard body fluid loss by providing a mechanical barrier

regulate body temperature through radiation, conduction, convection, and evaporation

provide sensory perception via free nerve endings and receptors

what to inspect on the skin

location, distribution, grouping, type, color, size

what to palpate on the skin

mobility, moisture, temperature, turgor, texture

what do primary skin lesions develop from

response to change in the internal or external environment of the skin

what do secondary skin lesions develop from

changes in the natural progression of the primary lesion or due to self-induced changes

thickened skin with distinct borders

lichenification

hard and rough surface caused by dried sebum, exudate, blood or necrotic tissue

crusted

heaped up, horny epithelium, flaky

scaly

increased water content, soggy

macerated

thin, linear erosion or ulcer

fissure

loss of skin or tissue

atrophy

shallow, hemorrhagic excavation (linear or punctate) from scratching

excoriated

partial break in the epidermis

erosion

full thickness loss of the epidermis

ulcer

terms to describe skin lesion borders/margins

discrete

indistinct

active/advancing

irregular

border raised above center

a flat, nonpalpable spot

macule

macule > 10 mm

patch

a solid palpable lesion usually < 5 mm, but sometimes up to 10mm

papule

papule > 10 mm

nodule

a plateau like lesion > 10 mm

plaque

circumscribed, elevated lesion < 5 mm containing serous fluid

vesicle

vesicle > 5 mm

bulla

superficial, elevated lesion containing pus

pustule

transient, migratory, elevated lesion with edema

wheal