Porth Chapter 61 Flashcards
pigmentary skin disorders
Melanocytes:
- Absence of melanin production, as in: Vitiligo, Albinism
- Increase in melanin: Mongolian spots, Melasma
rashes
Temporary eruptions of the skin; Childhood diseases, heat, diaper irritation, or drug-induced reactions
lesions
A traumatic or pathologic loss of normal tissue continuity, structure, or function
types of rashes
- Blanched (white)
- Erythematous (reddened)
- Hemorrhagic or purpuric (containing blood)
- Pigmented
ringworm / fungal infections
Superficial fungal infections: Tinea corporis, Tinea faciale, Tinea capitis, Tinea pedis, Tinea unguium, Tinea versicolor, Tinea incognito
primary bacterial infections
superficial
- Impetigo—appears as a small vesicle or pustule or as a large bulla on the face or elsewhere
- Ecthyma—ulcerative form of impetigo
secondary bacterial infections
deep cutaneous infections; 1. Infected ulcer
2. Cellulitis
Human papillomavirus
Verrucae (warts) are common benign papillomas.
Herpes simplex virus
Type 1: The organism is spread by respiratory droplets or by direct contact with infected saliva.
Type 2: Genital herpes
Herpes zoster/shingles
Localized vesicular eruption distributed over a dermatomal segment of the skin
noninflammatory acne
Comedones; Plugs of material that accumulate in sebaceous glands that open to the skin surface
inflammatory acne
Papules, pustules, nodules, and, in severe cases, cysts; Believed to develop from the escape of sebum into the dermis and the irritating effects of the fatty acids contained in the sebum
Acne vulgaris
Chronic inflammatory disease of the pilosebaceous unit
Acne conglobata
Comedones or cysts have multiple openings, large abscesses, and interconnecting sinuses; Discharge is odoriferous, serous or mucoid, and purulent; Affected persons have anemia with elevated white blood cell counts, sedimentation rates, and neutrophil counts
Rosacea
Chronic inflammatory process accompanied by vascular instability with leakage of fluid and inflammatory mediators into the dermis; Accompanied by gastrointestinal symptoms
Types:
- Erythematotelangiectatic
- Papulopustular
- Ocular
- Phymatous
Contact dermatitis
Allergic contact dermatitis results from a cell-mediated, type IV hypersensitivity response.
Irritant contact dermatitis is caused by chemicals that irritate the skin.
Atopic dermatitis
Inflammatory skin disorder that is characterized by poorly defined erythema, edema, vesicles, and weeping at the acute stage
Lichenification in the chronic stag
Nummular eczema
Coin-shaped papulovesicular patches involving the arms and legs
Lichenification and secondary bacterial infections are common.
Drug-Induced Skin Eruptions
Systemic drugs cause generalized skin lesions.
Topical drugs are usually responsible for localized contact dermatitis types of rashes.
Bullous skin lesions
Erythema multiforme minor
Stevens-Johnson syndrome
Toxic epidermal necrolysis
Skin detachment
Papulosquamous Dermatoses
Skin disorders characterized by scaling papules and plaques
Psoriasis
Pityriasis rosea
Lichens planus
Arthropod Infestations
Scabies
Pediculosis
Ticks
Rocky mountain spotted fever
Lyme disease
uvc rays
Short (100 to 289 nm); do not pass through the earth’s atmosphere
uvb rays
290 to 320 nm; responsible for nearly all the skin effects of sunlight
uva rays
321 to 400 nm; can pass through window glass, are more commonly referred to as sun tanning rays
Acute Effects of Ultraviolet Rays of Sunlight
Short-lived and reversible
Erythema
Pigmentation
Injury to Langerhans cells and keratinocytes
Chronic Effects of Ultraviolet Rays of Sunlight
Directly damaging skin cells
Accelerating the effect of aging on skin
Producing changes that predispose to development of skin cancer
sunburn
Excessive exposure of the epidermal and dermal layers of the skin to ultraviolet radiation
Resulting in an erythematous inflammatory reaction
Inflammation, blistering, weakness, chills, fever, malaise, and pain often accompany severe forms of sunburn
Measures for Protection from the Sun
Avoidance of sun exposure
Use of protective clothing
Use of sunscreens
Chemical agents absorb UVR.
Physical agents reflect UVR.
Biological agents reduce inflammation.
Broad-spectrum suntan lotions protect against both UVA and UVB.
Photosensitivity Occurring with Drugs
Definition: exaggerated response to ultraviolet light when the drug is taken in combination with sun exposure
Examples:
Some anti-infective agents
Antihistamines
Antipsychotic agents
Diuretics
Hypoglycemic agents
Nonsteroidal anti-inflammatory drugs
First-degree burns
(superficial partial-thickness burns) involve only the outer layers of the epidermis.
Second-degree partial-thickness burns
involve the epidermis and various degrees of the dermis.
Second-degree full-thickness burns
involve the entire epidermis and dermis.
Third-degree full-thickness burns
extend into the subcutaneous tissue and may involve muscle and bone.
Estimation of Total Body Surface Area Involved in Burn
Rule of nines
Multiple of 9%
Perineum 1%
Arm 9%
Leg 18%
Anterior trunk 18%
Posterior trunk 18%
Head 9%
Lund and Browder chart
American Burn Association classification of burns
Systemic Complications of Burn Tissue
Magnitude of the response is proportional to the extent of injury.
Hemodynamic instability
Impaired respiratory function
Hypermetabolic response
Major organ dysfunction
Sepsis
Treatment of Burns
Immediately submerge area to cool tissue
Emergency care
Resuscitation
Stabilization
Maintaining cardiac and respiratory function
Intermediate and long-term treatment is dependent on the extent of the injury.
Protection from desiccation
Escharotomy/fasciotomy
Pressure Ulcers (Bedsores)
Ischemic lesions of the skin and underlying structures caused by unrelieved pressure
Four factors contribute to the development of pressure ulcers.
Pressure
Shear forces
Friction
Moisture
Prevention of Pressure Ulcers (Bedsores)
(1) Identifying at-risk persons who need preventative measures and the specific factors placing them at risk
(2) Maintaining and improving tissue tolerance to prevent injury
(3) Protecting against the adverse effects of external mechanical forces (i.e., pressure, friction, and shear)
(4) Reducing the incidence of pressure ulcers through educational programs
The Development of Skin Cancer
Nevi (moles)—benign tumors of the skin that predispose individual to cancer
Nevocellular nevi
Dysplastic nevus
Great tendency to transform
Malignant melanoma
Rapidly progressing malignant tumor of the melanocytes
Basal cell carcinoma
Neoplasm of the nonkeratinizing cells of the basal layer of the epidermis; most common skin cancer in white-skinned people
Squamous cell carcinomas
Second most frequently occurring malignant tumors of the outer epidermis
Four Types of Melanomas
Superficial spreading
Nodular
Lentigo maligna
Acral lentiginous
Skin Disorders of Infancy
Mongolian spots
Hemangiomas
Port-wine stains
Nevi
Vascular and pigmented birthmarks
Diaper rash
Prickly heat
Cradle cap
Skin Manifestations of Common Infectious Disease
Roseola infantum
Rubella
Rubeola (measles)
Varicella
Scarlet fever
Normal aging changes
Diminution in subcutaneous tissue
Thinning of epidermal and dermal layers
Decrease in the number of melanocytes, Langerhans cells, and Merkel cells
Decrease and thickening of blood vessels
Skin Lesions Common among the Elderly
Skin tags
Keratoses
Lentigines
Vascular lesions
