Skin Anatomy and Physiology

Skin Layers

• Epidermis: Outermost layer of the skin.
• Dermis: Inner, supportive layer of the skin.
• Subcutaneous layer (Hypodermis): Layer of fat and connective tissue beneath the dermis, insulates the body, protects from trauma, regulates temperature.

Skin Appendages

• Nails: Hard plates of keratin, tough protein also found in skin and hair.
• Hair: Soft strands of keratin, same protein as nails but softer, more flexible.
  • Two types of hair: vellus (fine, soft hair) and terminal (coarser, pigmented hair)
• Eccrine glands: Coiled tubules that open directly onto the skin surface, produce dilute saline solution called sweat.
• Apocrine glands: Produce thick, milky secretion, open into the hair follicles.

Infant and Children

• Vernix caseosa: Thick, cheesy substance present at birth made up of sebum and shed epithelial cells.

Aging Adult

• Skin becomes thinner, more fragile, and less elastic.
• Decreased subcutaneous fat, leading to increased risk of injury and cold sensitivity.
• Reduced melanocyte function, affecting melanin production, leading to altered skin pigmentation.
• Decreased sweat gland activity, resulting in increased risk of overheating.
• Slower wound healing.
• Increased dryness.

Subjective Data

• Information provided by the patient about their feelings, symptoms, or experiences.
• Examples: pain, fatigue, nausea.
• Cannot be measured or observed directly by others.

Focused Database Assessment

• Emergent, urgent, important, etc.

Focused Database Assessment: Subjective data

• History of present illness (HPI): Detailed account of the onset, duration, and characteristics of the current skin concern.
• Past history: Prior skin conditions, allergies, surgeries, medications, treatments.
• Family history: Any family history of skin conditions, allergies, or genetic disorders.
• Social history: Lifestyle factors like occupation, hobbies, use of personal care products.
• Review of systems (ROS): Questions about symptoms related to any skin changes, hair loss, nail changes, rashes, itching, dryness, etc.

Inflammation acronym

• Swelling
• Heat
• A loss of function
• Redness
• Pain

Subjective Data: Aging Adults

• Any changes in skin texture, dryness, or moisture?
• Any skin lesions or growths?
• Any history of skin cancer or family history of skin cancer?

Common vs Normal

• Delayed skin healing: Common in aging adults.

Physical Examination

• Inspect and palpate the skin: Overall skin condition, color, texture, temperature, moisture, vascularity, edema, lesions.
• Inspect intertriginous areas: Regions where skin touches skin (under breasts, groin, skin folds).

TACO: Assessing Lesions

• Type: Describe the lesion (e.g., papule, macule, vesicle, etc.)
• Amount: Number of lesions present.
• Color: Note the color (e.g., red, brown, black, etc.)
• Consistency: Feel the lesion; is it smooth, rough, firm, etc.
• Odor: Does the lesion have a specific odor?

Inspect Skin Color

• Color*
• Pallor: Paleness, may be caused by anemia, shock, or reduced blood flow.
• Erythema: Redness, may be caused by inflammation, infection, or increased blood flow.
  • Flushing: Diffuse redness, often seen in fever, embarrassment, or alcohol consumption.
  • Cyanosis: Bluish discoloration, may indicate lack of oxygen in the blood.
    • Peripheral cyanosis: Blueness of the extremities, may be caused by cold temperatures or poor circulation.
    • Central cyanosis: Blueness of the lips, tongue, and mucous membranes, may indicate a more serious condition like heart or lung disease.
• Jaundice: Yellowing of the skin and sclera (whites of the eyes), may be caused by liver disease, bile duct obstruction, or excessive red blood cell breakdown.

Ridges in Nails

• Ridges in nails can sometimes indicate malnutrition, but they can also be associated with other conditions.
• Other conditions: Psoriasis, eczema, or even normal aging.
• Important: Check the patient's diet and health if ridges are seen.

Detecting Color Changes in Dark Skin

• Assess for changes in pigmentation, such as darkening or lightening of the skin.
• Examine for areas where the skin appears more taut or shiny.
• Look for subtle changes in texture, such as increased dryness or flakiness.
• Note any areas of redness, warmth, or swelling.

Mottling

• Typically seen in Caucasian skin.
• Patchy, purplish or bluish discoloration of the skin.
• May be caused by cold temperatures, shock, or poor circulation.

Moisture

• Diaphoresis: Excessive sweating, may be caused by fever, anxiety, infection, or other medical conditions.
• Dryness: Lack of moisture, may be caused by dehydration, skin conditions like eczema or psoriasis, or medications.

Vascularity/Bruising

• Petechiae: Small, pinpoint hemorrhages under the skin, may be caused by infection, trauma, or certain medications.
• Ecchymosis: Larger areas of bruising, may be caused by trauma, bleeding disorders, or certain medications.
• Purpura: Purple or red discoloration of the skin, may be caused by bleeding under the skin, infections, or autoimmune disorders.

Lesions

• Note: color, elevation, shape, size, exudate.
• Examples:
  • Macules: Flat, non-palpable lesions (e.g., freckles, moles)
  • Papules: Elevated, solid lesions (e.g., warts, pimples)
  • Nodules: Elevated, solid lesions larger than papules (e.g., tumors)
  • Vesicles: Fluid-filled, raised lesions (e.g., blisters)
  • Pustules: Pus-filled, raised lesions (e.g., acne)

Texture

• Expected: Smooth, firm.
• Variations: Roughness, dryness, flakiness.

Edema (Fluid Accumulation in Interstitial Spaces)

• Grading Edema:
  • 1+: Mild pitting, slight indentation with pressure, disappears rapidly.
  • 2+: Moderate pitting, indentation subsides in 10-15 seconds.
  • 3+: Deep pitting, indentation lasts for more than 1 minute.
  • 4+: Very deep pitting, indentation may last for several minutes.

Assessing Turgor

• Textbook answer: Assess turgor on the body by gently pinching the skin on the anterior chest, abdomen, or back of the hand.
• Possible causes of decreased turgor: Dehydration.

Taut Skin

• Caused by edema.
• Skin appears tight and stretched.

Inspect and Palpate the Hair

• Distribution: Is hair evenly distributed, or are there any areas of thinning or alopecia (hair loss)?
• Texture: Is the hair fine, coarse, or wiry?
• Color: Is the hair evenly colored, or are there any changes in coloration (e.g., graying, patchy discoloration)?
• Quality: Is the hair shiny, dull, or brittle?
• Any infestations: Lice or nits?
• Scalp lesions and infestations:

Inspect and Palpate the Nails

• Nail Plate: Inspect for shape, contour, thickness, and any abnormalities.
• Nail Bed: Inspect for color, capillary refill, and any abnormalities.
  • Clubbing: Enlarged fingertips and thickened nail beds, may be caused by chronic lung disease, heart disease, or other conditions.
• Nail Matrix: Inspect for any bleeding, inflammation, or other abnormalities.
  • Paronychia: Inflammation around the nail, often caused by infection.
• Nail Cuticle: Inspect for any abnormalities, such as hangnails, dryness, or inflammation.
  • Hangnails: Small tears in the cuticle.
• Capillary Refill: Gently press on the fingernail and observe the time it takes for the blood to return. Normal capillary refill time is less than 2 seconds.

Self Skin Exams

• Once a month!!

Developmental Competence: Adolescents

• Increased sebaceous gland activity, leading to acne.
• Hair growth: Puberty, development of axillary and pubic hair.

Developmental Competence: Pregnancy

• Increased pigmentation: Linea nigra (dark line down the abdomen), melasma (dark patches on the face), areolae of nipples darken.
• Striae gravidarum (stretch marks) may develop on the abdomen, breasts, and thighs.

Developmental Competence: Aging Adult

• Epidermis thins, causing increased sensitivity to trauma.
• Decreased subcutaneous fat, leading to greater risk of cold sensitivity.
• Slower wound healing.
• Decreased sweat gland activity, limiting thermoregulation.
• Reduced melanocyte activity, leading to skin pigmentation changes.
• Dryness: Reduced oil production.
• Increased scaling.
• Increased fragility of blood vessels, increasing risk of bruising.

Pressure Wounds

• If a pressure wound is covered in eschar, you cannot stage it!!!
• Staging: Stage I-IV, categorized by severity of tissue damage.
• Lower number, higher risk.

Trauma or Abuse: Hematomas

• Hematomas: Bruises, can be caused by trauma or abuse.
• Note: Size, shape, color, and location.
• Documentation is vital: Document the location, size, shape, and characteristics of any hematomas.

Intimate Partner Violence

• You do not report intimate partner violence.

Common Skin Lesions in Children

• Common skin lesions: Macule, papule, vesicle, pustule, nodule, wheal.
• Table 13-9 in textbook.

Common Skin Lesions

• Table 13-10 in textbook.
• Macule, papule, vesicle, pustule, nodule, wheal.

Herpes Simplex Virus

• Type 1 (HSV-1): Primarily causes oral herpes (cold sores), but can also cause genital herpes through oral-genital contact.
• Type 2 (HSV-2): Primarily causes genital herpes, usually sexually transmitted, but can occasionally affect oral area.

Abnormal Conditions of Hair

• Table 13-12 in textbook
• Alopecia (hair loss), hirsutism (excess hair growth), and abnormal hair texture.

Dehydration

• Skin turgor: decreased, skin may feel dry and flaky.
• Mucous membranes: Dry, sticky, and may appear cracked.
• Urine output: Decreased, may be concentrated and dark yellow.
• Thirst: Increased.
• Weight loss: May be present, depending on the severity of dehydration.

Developmental Competence - Aging Adult

• Skin becomes thinner, more fragile, and less elastic.
• Decreased subcutaneous fat, leading to increased risk of injury and cold sensitivity.
• Reduced melanocyte function, affecting melanin production, leading to altered skin pigmentation.
• Decreased sweat gland activity, resulting in increased risk of overheating.
• Slower wound healing.
• Increased dryness.

Quiz Answers

1. Sclera: Part of the eye, can show jaundice.
2. Palms: Can show pallor or erythema.

This quiz covers the layers of the skin, including the epidermis, dermis, and subcutaneous layer. It also explores skin appendages such as nails and hair, as well as differences in skin characteristics throughout life stages from infants to aging adults. Test your knowledge on the structure and function of skin.