Skin Disorders
A&P Review
- Epidermis
- Keratin
- Melanin
- Dermis
- Connective tissue
- Contains elastic and collagen fibers
- Contains nerves, blood vessels, and all sensory receptors
- Subcutaneous Tissue
- Fat cells
- Connective tissue
- Larger blood vessels
- Nerves
Appendages and Function of Skin
- Hair follicles
- Sebaceous glands
- Produce sebum
- Sweat gland
- Eccrine
- All over body
- Apocrine
- axillae, scalp, face, external genitalia
- Eccrine
- Functions of skin
- First line of defense for infection
- Prevents excessive fluid loss
- Controls body temperature
- Active in sensory perception
- Synthesis Vit D
Skin Lesions
- The physical appearance of the lesion is necessary to make a diagnosis.
- Skin lesions may be caused by:
- Systemic disorders
- Liver disease
- Systemic infections
- Chickenpox
- Allergies to ingested food or drugs
- Localized factors
- Include exposure to toxins
- Macule
- flat, circumscribed
- Papule
- small, solid elevation
- Nodule
- firm, raised, deep
- Pustule
- raised, often with a "head," filled with exudate or "pus"
Description of Some Skin Lesions
| Lesion | Description |
|---|---|
| Macule | Small, flat, circumscribed lesion of a different color than the normal skin |
| Papule | Small, firm, elevated lesion |
| Nodule | Palpable elevated lesion; varies in size |
| Pustule | Elevated, erythematous lesion, usually containing purulent exudate |
| Vesicle | Elevated, thin-walled lesion containing clear fluid (blister) |
| Plaque | Large, slightly elevated lesion with flat surface, often topped by scale |
| Crust | Dry, rough surface or dried exudate or blood |
| Lichenification | Thick, dry, rough surface (leather-like) |
| Keloid | Raised, irregular, and increasing mass of collagen resulting from excessive scar tissue formation |
| Fissure | Small, deep, linear crack or tear in skin |
| Ulcer | Cavity with loss of tissue from the epidermis and dermis, often weeping or bleeding |
| Erosion | Shallow, moist cavity in epidermis |
| Comedone | Mass of sebum, keratin, and debris blocking the opening of a hair follicle |
Pruritus (itching)
- Associated with
- Allergic responses
- Chemical irritation caused by insect bites
- Infestations by parasites (e.g., scabies)
- Mechanism not totally understood
- Release of histamine in a hypersensitivity response causes marked pruritus.
- Infection may result from breaking the skin barrier.
- Caused by scratching
Skin Infections
- May be caused by bacteria, viruses, fungi, other types of microbes, parasites
- Caused by opportunistic microbes
- Minor abrasions or cuts
- Serious infections may develop.
- Causative organism needs to be identified for appropriate treatment.
Diagnostic Tests for Skin Lesions
- Culture and staining of specimens
- Bacterial infections: microscopic and direct observations
- Specific procedures for fungal or parasitic infections
- Biopsy
- Detection of malignant changes
- Safeguard prior to or following removal of skin lesions
- Blood tests
- Helpful in diagnosis of conditions caused by allergy or abnormal immune reaction
- Skin testing using patch or scratch method
Inflammatory Skin Disorders
| Condition | Etiology | Pathophysiology | Manifestations | Treatment |
|---|---|---|---|---|
| Contact Dermatitis | Allergen, chemical | Type IV hypersensitivity; location clue to ID of source | Red, swollen, vesicles, itching or pain | Remove cause |
| Urticaria (hives) | Ingested substance | Type I hypersensitivity | Hard, raised , red lesions, itching, can progress to anaphylaxis | Antihistamines, corticosteroids |
| Atopic Dermatitis | Inherited allergy | Type I hypersensitivity | Infants: Moist, red, itchy, vesicles, common on arms, legs and buttocks Adults: thick, leathery patches, itching | Remove cause; antihistamines, corticosteroids |
| Psoriasis | Genetic | Autoimmune; Onset teens; skin cells build up and form scales | Small red patches covered with silvery scales, dry cracked skin, itching, burning, thick pitted nails, painful joints | Glucocorticoids, methotrexate |
| Scleroderma | Unknown | Collagen deposits in tiny vessels, decreasing blood flow to skin | Hard, shiny, immovable areas of skin, skin tightness | Varies based on type and manifestations |
More Skin Disorders
| Condition | Etiology | Pathophysiology | Manifestations | Treatment |
|---|---|---|---|---|
| Cellulitis | Bacteria; usually due to boil, injury | Pathogenic organism makes its home on top of the skin or in underlying layers | Red, warm, swollen, pain, red streaks (proximal to distal) | Antibiotics |
| Furuncle (carbuncle – large collection) | Bacteria; begins in hair follicle | As above | Firm, red lesion, painful nodule can develop into abscess with exudate | Warm compresses; analgesics; ABX; may need to drain abscess |
| Herpes Simplex - Type I – oral; Type 2 – genital and/or oral | Viral | May be asymptomatic with primary infection; virus can lay dormant. Triggers any type of physiologic stress | Burning, tingling sensation; vesicles; spontaneous healing 2-3 weeks | No cure; antiviral drugs may help to decrease severity of manifestations |
| Warts | Viral; many types | Viral shedding spreads infection; some resolve on their own over time; can be persistent | Papule white or tan color; painful especially on feet | Laser, liquid nitrogen |
Even More Skin Disorders
| Condition | Etiology | Pathophysiology | Manifestations | Treatment |
|---|---|---|---|---|
| Impetigo | Bacteria | Easily spread by direct contact; common in classrooms and sport teams | Vesicles with honey consistency drainage; most common on face; pruritis | Topical antibiotics |
| Tinea (Ringworm) | Fungal | Several types, different name for areas of the body | Depends on part of body involved; round ring with clear center; itching | Antifungal medication |
| Scabies | Mite | Female burrows under skin and lays eggs | Tiny light brown lines; small vesicles; itching | Medicated soap |
| Pediculosis | Lice | Female lice lay eggs on hair shaft close to scalp; the egg or nit is small and white; once hatched attach and suck blood | Visible nits, itching | Medicated soaps, special comb; Need to treat all cloth objects |
Infectious Skin Disorders
| Condition | Etiology | Pathophysiology | Manifestations | Treatment |
|---|---|---|---|---|
| Acute Necrotizing Fasciitis | A mixture of aerobic and anaerobic microbes; injury | This will affect all layers of skin and into muscles | Red, pain, gangrene; fever, tachycardia, HTN, confusion, organ failure, death | ABX, surgery, amputation |
Pressure Ulcers
- Patho
- Skin breakdown due to pressure
- Ischemia leads to necrosis, wounds
- Causes/Risk factors
- Think about the Braden scale (mobility, moisture, sensation, nutrition, friction & shear)
- Poor circulation and chronic diseases
- Age (infants and older adults)
- Manifestations
- Stage I, II, III, IV, and unstageable
- Complications
- Osteomyelitis
- Sepsis/bacteremia
Stages of Pressure Injury
- Stage 1: The skin is discolored. The skin appears red with lighter skin or blue/purple in darker skin tones. When pressing on the area, it does not blanche (does not turn white) and the temperature may be altered compared to surrounding tissue. The fastest healing ulcer occurs in this stage.
- Stage 2: The skin has superficial damage. The top layer of the skin is lost and may look like a blister. (intact or popped)
- Stage 3: The skin damage is deeper, extending to the adipose layer of the skin. This is now in the fatty tissue layer.
- Stage 4: The skin is severely damaged, extending to the muscles and bones, tendons, or ligaments. This is the most dangerous stage as infection can be life-threatening to the individual.
- Unstageable: Full-thickness skin loss occurs and the exposure is covered by slough (yellow, tan, gray, green, or brown) and/or eschar (tan, brown, or black) in the wound bed
Cancers of the integumentary system
- Squamous cell carcinoma
- Basal cell carcinoma
- Malignant melanoma
Cancers
| Condition | Etiology | Pathophysiology | Manifestations | Treatment |
|---|---|---|---|---|
| Squamous cell carcinoma | Sun exposure; tobacco (lip and mucous membrane) | Lesions found on exposed areas of skin Commonly slow growing Not common to metastasize | Scaley, slightly elevated reddish lesion; irregular border; central ulceration | Removal of affected tissue |
| Malignant melanoma | More serious; genetics, UV exposure; hormones | Nevi grow and change Grow quick Metastasize Poor prognosis | Area of the mole increased Border is irregular Color is changed in mole Diameter of the mole is increased | Surgery, radiation, chemotherapy |
| Kaposi sarcoma | Skin cancer seen in the AIDS client; occasionally seen in non-AIDS client | Arises from inside the blood vessels | Purple macules face, oral mucosa, scalp, lower extremities; no itching, painless | Surgery, radiation, chemotherapy |
Warning Signs of Skin Cancer
- A sore that does not heal
- A change in shape, size, color, or texture of a lesion, especially an expanding, irregular circumference or surface
- New moles or odd-shaped lesions that develop
- A skin lesion that bleeds repeatedly, oozes fluid, or itches
Guidelines to Reduce Risk of Skin Cancers
- Reducing sun exposure at midday and early afternoon
- Covering up with clothing
- Remaining in shade
- Wearing broad-brimmed hats to protect face and neck
- Applying sunscreen or sunblock
- Protecting infants and children from exposure and sun damage to skin