Skin, Hair, and Nails

Epidermis

The surface epithelium of the skin, overlying the dermis

Stratum germinativum

The deepest layer of the epidermis

Also called the basal cell layer

What is in the stratum germinativum?

Keratin and melanocytes

Keratin

A tough, structural protein that makes up the outer layer of your skin, hair, and nails, providing a protective barrier against damage and water loss

It is produced by keratinocytes

Melanocytes

Special cells in the skin, hair, and eyes that produce and distribute melanin, a pigment responsible for color

Stratum corneum

Outer horny cell layer consisted of dead kernatized cells 

Cells are constantly being replaced with cells below 

Where does skin color come from?

Melanin, carotene, and underlying vascular bed

What else is color in the skin impacted by?

Thickness and presences of edema

Dermis 

Inner supportive layer below the epidermis 

Mostly connective tissue and collagen 

Resilient, elastic tissue 

Nerves, sensory receptors, blood vessels and lymphatic 

Appendages

Collagen

Tough protein which helps the skin resist tearing

Appendages

Hair follicles, sebaceous glands, and sweat glands

Vestigial for humans (hair)

Reduced or non-functional anatomical features or behaviors that were a function in an organism’s ancestors but have lost their purpose through evolution 

What is the hair?

Threads of keratin

What is the visible portion of the hair?

Shaft

What root produces new cells?

Bulb matrix

What is hair growth?

Cyclical

Arrector pili

Muscular area around the follicle that contract and elevate hair when skin is exposed to cold or emotional states

Goose bumps

Sebaceous glands

Produce sebum 

Through follicles 

Lubricates skin and hair 

Everywhere except palms and soles 

Most abundant on scale, forehead, face and chin

Eccrine

Produces saline solution (i.e. sweat)

Evaporation of sweat reduces body temperature

Widely distributed throughout the body

Apocrine

Thick, milky secretion and open into the hair follicles

Located mainly in the axilla, anogenital, nipples, and navel

Secretion occurs wit emotional and sexual stimulation

Bacterial flora react with apocrine secretions to produce body odor

Nails

Hard plates of keratin 

Nail plate

Clear with longitudinal ridges that increase with aging

Nail bed 

Consists of high vascular epithelial cells 

Lunula

White, semilunar area proximal to the end of the nail

Nail matrix

Where new keratinized cells are formed (covered by lunula)

Function of the skin

Protection, perception, temperature regulation, identification, communication, wound repair, absorption and excretion, production of Vitamin D

Lanugo

Fine down hair of the newborn

Vernix Casosa

Thick, cheesy substance made up of sebum and sheds of epithelial cells

Chloasma

Increased pigment in the face during pregnancy

Linea Nigra

Darkened midline in abdomen during pregnancy

Striae Gravidarum

Stretch marks

What happens when there is a loss of elastin, collagen, and subcutaneous fat

Wrinkles form 

Aging Adult: Skin

Loss of elastin, collagen, and subcutaneous fat

Reduction in muscle tone

Decreased number and function of sebaceous and sweat glands→Dry skin

Temperature regulation decreases-May lead to heat stroke

Increased vascular fragility

Senile purpura

Increased vascular fragility

Transcultural considerations

Lower incidence of skin cancer among Native Americans and darkly pigmented persons

Hair condition→Indicator of nutrition status

Use palate or sclera to assess for jaundice in those with darker color

Subjective data: Skin, hair, nails

Hx of skin disease? Allergies? Change in pigmentation? Change in mole? Excessive dryness or moisture? Pruritus? Excessive ecchymosis? Rash or lesion? Medication? Rx or OTC? Recent hair loss? Change in nails? Environmental occupational hazards? Self-care behaviors?

Macule

Freckle

Flat, discolored area of the skin<1 cm in diameter

Nevi 

Mole

Bengin skin growth caused by a cluster of pigment-producing cells called melanocytes

Papules

Pimple

Small, raised bump on the skin that is solid and firm

Liver spots

Brown or black patches r/t clusters of melanocytes that typically appear with age or prolonged UV radiation from the sun

Seborrheic Keratosis

Pigmentation appears greasy, dark & stuck on 

Pallor

Paleness, loss of color in the skin

Erythema

Redness

Cyanosis

Bluish discoloration in skin, lips, or nails 

Lack of oxygenated hemoglobin in the blood

Jaundice

Yellow discoloration caused by excess bilirubin

What s/sx are associated with peripheral vasoconstriction?

Cold, pale, and subjective reports of “freezing to death”

Skin temperature

Should be warm and equal bilaterally

Hypothermia

Too low temperature

General→Accompanies a circulatory disturbance (i.e., shock)

Local→Peripheral artery insufficiency (i.e., Raynaud’s)

Hyperthermia

Too high temperature

General→Occurs with increased metabolic rate (i.e., fever, heavy exercise)

Local→Trauma, infection, sunburn

Diaporesis

Excessive sweating

Perfuse perspiration, accompanies an increased metabolic rate 

What do you check for dehydration?

Check mucous membranes

Skin texture

Should feel smooth, firm, and even

Edema 

Fluid accumulating in the intracellular spaces 

Makes normal skin color and observes pathological conditions (i.e., jaundice and cyanosis) 

Where should you check for edema?

Ankles and anterior tibia

Pitting

Indentation

What is the grading scale of edema? 

1+ Mild

2+ Moderate, indentation subsides rapidly 

3+ Deep pitting, leg looks swollen 

4+ Very deep pitting, indentation lats awhile, leg looks very swollen 

Vascularity or bruising

Cherry (senile) angiomas

Excessive ecchymotic areas above knees and elbows

Pattern (skin lesion)

Annular, grouped, confluent, linear, discrete

Size (skin lesion)

Measure in cm 

Location and distribution (skin lesions)

Generalized, localized, diffused, discrete

Exudate (skin lesions)

Note color and order

Annular (skin lesion)

Circular shape (i.e., ringworm)

Grouped (skin lesion)

HSV

Confluent (skin lesion)

Merge into one another (no defined edges)

Discrete (skin lesion)

Separate and discrete from surrounding skin

Primary skin lesions

Initial skin abnormality present at the beginning of a disease or from birth

Secondary skin lesion

Developed from a primary lesion or as a direct result of patient activities (i.e., scratching) or an underlaying condition’s progression

Objective data: Hair

Color, texture, distribution, lesions

Clubbing

Nails become enlarged, rounded, and curved downward at the edges

Capillary refill time (CRT)

Measures global and local tissue perfusion

Blanch skin of the index finger for 10 seconds, skin should return to baseline color in less than  3 second 

What are medical consideration for clubbing in the fingernails

Emphysema, bronchitis, chronic respiratory issues

Mongolian spots

Benign birthmarks that appear as flat, blue-gray areas on infant’s skin. Most commonly found on lower back or buttocks

Prominent in infants of Asian, African and Native American descent

Usually disappear by adolescence

Stork bite 

Birthmark on the back of the neck 

Carbuncle

Deep, painful skin infection that involves multiple hair follicles

Usually requires antibiotics to treat

Pressure injuries

Localized damage to the skin an underling soft tissue due to prolonged pressure

Which nutrient is essential for wound healing? 

Protein 

Braden scale

Tool that is used to assess a person’s risk of developing a pressure ulcer?

What is the best intervention to prevent pressure injuries?

Rotate the pt every 2 hours

Early mobility as tolerated

Stage 1

Non-blanchable erythema 

Skin is intact and red but unbroken 

Localized, does not blanch 

Stach 2

Partial-thickness skin loss

Loss of epidermis and exposed dermis

Shallow abrasion or open blister with red/pink wound bed

Stage 3

Full-thickness skin loss

Extends into subcutaneous tissue and resembles a crater

Subcutaneous fat, granulation tissue, and rolled edges visible

Stage 4 

Full-thickness skin/tissue loss

Involves all skin layers and extends into supporting tissues

Muscle, bone, tendon, slough or eschar, rolled edges, and tunneling visible

Slough

Stringy matter attached to wound bed

Eschar 

Black or brown necrotic tissues

Deep Tissue Injury (DTI)

Localized, non-blanch able color change to deep red, maroon, purple in intact, or non intact skin

Dark skin appears darker and does not blanch

Pressure injuries caused by medical devices

Skin or mucosa breakdown that takes the patter or shape of a medical device (i.e., oxygen tubing, airway pressure masks, ET tubes, etc)