Integumentary System and Nutrition for Nursing

Functions of the Integumentary System

• Physical & Protective Functions

  • Protection: The skin serves as a vital barrier against several external threats: pathogenic invasion, harmful ultraviolet (UV) radiation, and direct physical trauma or injury.
  • Thermoregulation: Temperature control is achieved through physiological mechanisms such as sweat glands and the dilation or constriction of dermal blood vessels, which function to release or conserve body heat respectively.
  • Sensation: Specialized sensory receptors are embedded within the skin to detect a variety of stimuli, including touch, pressure, pain, and temperature changes.

• Metabolic & Sensory Functions

  • Vitamin D Synthesis: This metabolic process is initiated in the skin layers upon exposure to sunlight.
  • Excretion: Metabolic waste products, including water, salts, and urea, are expelled from the body via sweat.
  • Fluid Balance: The skin acts as a semi-permeable barrier that prevents excessive water loss and subsequent dehydration.
  • Immunity: Highly specialized Langerhans cells are present to detect and trap invading pathogens, providing an immunological defense layer.

• Clinical Considerations

  • The skin is recognized as the largest organ of the human body and represents the first line of defense against most biological and physical insults.

Anatomy of the Skin: The Three Main Layers

• Epidermis

  • This is the outermost, avascular layer of the skin.
  • It functions as a waterproof, keratinized barrier.
  • It contains essential cell types such as melanocytes (which produce the pigment melanin) and Langerhans immune cells.

• Dermis

  • This layer consists of thick connective tissue.
  • It houses several critical components, including blood vessels, nerves, glands, and hair follicles.
  • The presence of collagen and elastin fibers provides the skin with its structural strength and the ability to stretch and recoil.

• Hypodermis (Subcutaneous Layer)

  • Composed primarily of adipose (fat) and loose connective tissue.
  • Functions include body insulation, energy storage, cushioning for underlying structures, and anchoring the skin to the deeper muscle and bone tissue.

The Epidermis: Detailed Five Strata

• Stratum Corneum

  • Consists of a layer of $20$ to $30$ strata of dead, keratin-filled cells.
  • Forms a tough, waterproof barrier that is subjected to continuous shedding.

• Stratum Lucidum

  • A thin, clear band composed of flattened, dead cells.
  • This layer is exclusively found in thick skin regions, specifically the palms of the hands and the soles of the feet.

• Stratum Granulosum

  • A layer where cells fill with keratohyalin granules.
  • Cells in this layer begin the process of death as they are pushed further toward the superficial surface.

• Stratum Spinosum

  • Comprised of several rows of spiny-appearing keratinocytes.
  • Contains Langerhans cells, which are integral to the body's immune defense mechanisms.

• Stratum Basale

  • The deepest epidermal layer and the primary site of constant mitosis (cell division).
  • It is the home of melanocytes and Merkel cells (associated with the sense of touch).

• Mnemonic for Strata (Superficial to Deep)

  • "Come, Let's Get Sun Burned": Corneum, Lucidum, Granulosum, Spinosum, Basale.

The Dermis: Structure and Accessory Components

• Dermal Sublayers

  • Papillary Layer: The superficial sublayer characterized by dermal papillae. These papillae house capillaries and Meissner corpuscles responsible for detecting light touch. This layer is also responsible for the formation of unique fingerprints.
  • Reticular Layer: The deep sublayer consisting of dense collagen and elastin. This layer provides skin with elasticity and structural integrity while housing most accessory structures.

• Key Intradermal Structures

  • Hair Follicle & Shaft: The structure from which hair grows; it is associated with the arrector pili muscle, which contracts to cause hair to stand upright (goosebumps).
  • Sebaceous (Oil) Gland: Secretes a lipid-rich substance called sebum that serves to lubricate both the skin and the hair.
  • Eccrine Sweat Gland: A coiled glandular structure that releases a watery sweat to facilitate body cooling through evaporation.
  • Blood Vessels: These provide necessary nourishment to skin tissues and play a central role in thermoregulation.
  • Pacinian Corpuscle: Sensory receptors specifically adapted for the detection of deep pressure and vibration.

Accessory Structures: Hair, Nails, and Glands

• Hair and Nails

  • Hair: Provides essential protection and insulation; it originates from and grows within the follicle.
  • Arrector Pili: A tiny smooth muscle attached to the follicle that produces goosebumps in response to cold or stress.
  • Nails: Composed of hard keratin, these structures protect the distal tips of the fingers and toes.
  • Nail Components: Includes the nail root, the nail body (or plate), and the lunula (the pale, half-moon-shaped area at the base).

• Glandular Secretions

  • Sebaceous Glands: Produce oily sebum for lubrication.
  • Eccrine Sweat Glands: Produce watery sweat for systemic cooling.
  • Apocrine Sweat Glands: Found in the axillae (armpits) and groin; they produce a thicker sweat which, when broken down by bacteria, is the primary cause of body odor.
  • Ceruminous Glands: Located in the ear canal; these produce earwax, formally known as cerumen.
  • Mammary Glands: These are modified sweat glands specifically adapted for the production of milk.

Clinical Assessment and Nursing Priorities

• General Assessment Parameters

  • Nurses must inspect the skin for color, temperature, moisture, turgor, and integrity.
  • The skin is considered a window into systemic health; findings such as pallor, cyanosis, and jaundice often signal underlying systemic pathologies.
  • Assessment should occur every shift as skin changes are often the first visible signs of client status alteration.

• Systematic Evaluation (Head-to-Toe)

  • Color: Assess for pallor, cyanosis, jaundice, or erythema. In dark-skinned clients, check nail beds, lips, and conjunctiva.
  • Temperature: Ensure skin is warm and symmetrical across both sides of the body; assessment should be performed using the back of the hand.
  • Moisture: Determine if the skin is dry, oily, or diaphoretic.
  • Turgor: Tested by tenting the skin over the sternum. A slow return to original position (tenting) indicates dehydration.
  • Integrity: Differentiate between intact skin and areas with rashes, skin tears, or open wounds.

• Specific Clinical Cues

  • Edema: Assessed by pressing over a bony prominence; pitting edema is graded on a scale from $1+$ to $4+$.
  • Lesions: Documentation must include precise location, pattern, color, drainage, and size measured in $mm$ or $cm$.
  • Bony Prominences: Critical areas including the sacrum, heels, hips, and elbows must be monitored for early signs of breakdown.
  • Dark Skin Tones: Inflammation or injury may be harder to visualize; rely on palpating for warmth, induration (hardness), or increased firmness.

Classification of Skin Lesions

• Primary Lesions (Found on previously healthy skin)

  • Macule: A flat area characterized by color change, measuring less than $1\,cm$ (e.g., a freckle).
  • Papule: A raised, solid lesion measuring less than $1\,cm$ (e.g., a mole).
  • Vesicle: A small, fluid-filled blister (e.g., herpes simplex lesion).
  • Pustule: A raised lesion containing pus (e.g., acne).
  • Wheal: A raised, edematous area (e.g., hives).
  • Nodule: A solid, deep lesion measuring over $1\,cm$.

• Secondary Lesions (Result from evolution or trauma to primary lesions)

  • Crust: Dried blood or exudate on the surface (e.g., a scab).
  • Scale: Flaking of dead epidermal cells (e.g., psoriasis plaques).
  • Ulcer: Loss of tissue extending into the dermis or deeper layers.
  • Fissure: A linear crack in the skin surface.
  • Excoriation: An abrasion or scratch resulting from surface-level trauma.
  • Lichenification: Thick, leathery skin texture caused by chronic rubbing or irritation.

• The ABCDE Rule for Melanoma Detection

  • A - Asymmetry: One half of the lesion does not match the other.
  • B - Border: Irregular, ragged, notched, or blurred edges.
  • C - Color: Varied shades of brown, black, or red.
  • D - Diameter: Greater than $6\,mm$.
  • E - Evolving: Any change in size, shape, color, or symptoms should be reported immediately.

Pressure Injuries: Staging, Risk, and Prevention

• Braden Scale

  • Used to quantify risk based on six categories: sensory perception, moisture, activity, mobility, nutrition, and friction/shear.
  • Lower scores indicate a higher risk for pressure injury development (e.g., a score of $10$ indicates severe risk).

• Staging Guidelines

  • Stage 1: Intact skin with non-blanchable redness (erythema).
  • Stage 2: Partial-thickness skin loss; characterized by a shallow open ulcer or a blister.
  • Stage 3: Full-thickness tissue loss where subcutaneous fat is visible, but muscle, tendon, and bone are not. Slough may be present.
  • Stage 4: Full-thickness tissue loss with exposed bone, tendon, or muscle.
  • Unstageable: The base of the injury is obscured by slough (yellow, tan, gray, green, or brown) or eschar (tan, brown, or black), making it impossible to determine the true depth.
  • Deep Tissue Pressure Injury: Maroon or purple discoloration of intact skin or a blood-filled blister.

• Prevention Strategies

  • Reposition immobile clients at least every $2\,h$.
  • Offload pressure from heels (float them using a pillow).
  • Maintain clean, dry skin.
  • Ensure adequate nutritional intake and hydration.

Wound healing and Drainage Types

• Phases of Wound Healing

  • Hemostasis: Occurs immediately; characterized by vasoconstriction and clot formation to stop bleeding.
  • Inflammatory (Days $1$–$4$): Marked by redness, warmth, and edema as white blood cells clean the wound site.
  • Proliferative (Days $4$–$21$): Granulation tissue (pink/beefy appearance) fills the wound bed and wound contraction occurs.
  • Maturation (Day $21$ to $2\,years$): Collagen remodels and reorganizes, increasing the strength of the scar tissue.

• Exudate Classification

  • Serous: Clear and watery; categorized as normal healing fluid.
  • Sanguineous: Fresh, bright red blood.
  • Serosanguineous: Pale pink, blood-tinged fluid.
  • Purulent: Thick, yellow, or green fluid; frequently foul-smelling and indicates infection.

• Healing by Intention

  • Primary Intention: Clean surgical incisions with sutured edges that heal rapidly.
  • Secondary Intention: Open wounds that heal from the bottom up through the formation of granulation tissue.
  • Tertiary Intention: Delayed primary closure; where a wound is left open to be cleaned or watched before being sutured.

Burn Depth and Rule of Nines

• Burn Classification

  • Superficial (1st Degree): Affects only the epidermis; red, dry, and painful (e.g., sunburn).
  • Superficial Partial-Thickness (2nd Degree): Extends into the upper dermis; characterized by moisture and blisters; highly painful.
  • Deep Partial-Thickness (2nd Degree): Extends into the deeper dermis; often requires skin grafting.
  • Full-Thickness (3rd Degree): Extends through the entire dermis; appears white or leathery and is frequently painless due to nerve destruction.
  • Fourth Degree: Extends beyond the skin into muscle and bone.

• Rule of Nines for Adults

  • Head and Neck: $9\%$
  • Each Arm: $9\%$
  • Each Leg: $18\%$
  • Anterior Trunk: $18\%$
  • Posterior Trunk: $18\%$
  • Genitals: $1\%$

• Medical Priorities (ABC)

  • Secure the airway (especially if inhalation injury is suspected).
  • Fluid resuscitation.
  • Pain management.
  • Prevention of infection and hypothermia.

Common Integumentary Infections and Conditions

• Cellulitis: A spreading bacterial infection of the skin and subcutaneous tissues resulting in redness, warmth, and swelling. Borders should be marked to monitor spread.
• Tinea: Fungal infections including ringworm or athlete's foot; characterized by the need to keep the affected area exceptionally dry.
• Herpes Zoster (Shingles): Painful blisters following a dermatomal pattern; clients must be isolated until the lesions have crusted over.
• Candidiasis: Yeast infection occurring in warm, moist skin folds.
• Scabies and Lice: Infestations of itchy mites or lice requiring specialized treatment and laundering of all linens.

Plant-Based Diets: Definitions and Spectrum

• Types of Vegetarianism

  • Flexitarian: Semi-vegetarian; eats mostly plants with occasional meat or fish.
  • Pescatarian: Excludes meat and poultry but includes fish and seafood.
  • Lacto-ovo Vegetarian: Excludes meat, poultry, and fish; includes dairy and eggs.
  • Lacto Vegetarian: Includes dairy but excludes eggs, meat, poultry, and fish.
  • Ovo Vegetarian: Includes eggs but excludes dairy, meat, poultry, and fish.
  • Vegan: Strictest form; excludes all animal-derived products including honey, eggs, and dairy.

• Restrictive Patterns

  • Raw Vegan: Uncooked plant foods processed at temperatures below approximately $118^\circ F$.
  • Fruitarian: Primarily raw fruits, nuts, and seeds; carries very high risks of deficiency.
  • Macrobiotic: Based on whole grains and vegetables; can be dangerously limited in some iterations.

Nutritional Risks and Patient Teaching for Vegans

• Nutrients of Concern

  • Vitamin B12: Found naturally only in animal products. Deficiency can cause irreversible nerve damage and megaloblastic anemia. Strict vegans must take a reliable supplement or consume fortified foods.
  • Iron: Plant-based iron is non-heme and less absorbable. It should be paired with Vitamin C (e.g., citrus, bell peppers) to enhance absorption.
  • Protein: Vegans should combine various plant sources (e.g., grains and legumes) as complementary proteins to obtain all essential amino acids.
  • Calcium & Vitamin D: Essential for bone health, especially if dairy is excluded.
  • Omega-3 (EPA/DHA): Sources include flax, chia, walnuts, or algae-derived supplements.

• High-Risk Populations

  • Pregnancy & Lactation: Increased requirements for B12, iron, folate, and DHA to support fetal development.
  • Infants & Children: High risk for stunted growth and B12 deficiency due to rapid developmental needs.
  • Older Adults: At risk for bone loss, muscle wasting, and reduced B12 absorption.

NCLEX-PN Scope and Coordinated Care Practice

• Practical Nurse (PN/LVN) Scope

  • PNs perform sterile dressing changes on stable clients.
  • PNs collect data and document findings (location, size in $cm$, stage, color, drainage, odor).
  • PNs reinforce teaching previously provided by the RN.
  • PNs cannot perform initial assessments, develop initial care plans, or provide initial teaching; these are Registered Nurse (RN) responsibilities.

• Delegation

  • The PN may delegate routine tasks to Unlicensed Assistive Personnel (UAP), such as repositioning an immobile client every $2\,h$.
  • UAPs cannot be delegated tasks requiring nursing judgment, such as staging a pressure injury or assessing wound drainage.

• Interdisciplinary Collaboration

  • Complex cases (e.g., a vegan client with a non-healing Stage 3 pressure injury) require collaboration with Dietitians, Wound Care Specialists, and Providers to address both nutritional gaps and specialized wound management.

Clinical Review Questions & Rationales

• Question: A surgical wound has thick, yellow-green drainage with a foul odor. What is the priority?
  • Answer: Notify the RN or provider.
  • Rationale: Purulent, foul drainage indicates infection and requires immediate medical attention.
• Question: Which vitamin must a strict vegan supplement?
  • Answer: Vitamin B12.
  • Rationale: Naturally occurring B12 is exclusive to animal products.
• Question: How is a stage 1 pressure injury documented?
  • Answer: Intact skin with non-blanchable redness.
  • Rationale: This describes the earliest stage of pressure-induced tissue damage.
• Question: What improves plant-based iron absorption?
  • Answer: Pairing iron-rich foods with Vitamin C.
  • Rationale: Vitamin C significantly enhances the bioavailability of non-heme iron.
• Question: Using the Rule of Nines, what is the percentage for a burn on the entire front of the trunk and one full arm?
  • Answer: $27\%$.
  • Rationale: Anterior trunk ($18\%$) plus one whole arm ($9\%$) equals $27\%$.