The Integumentary System - Skin Disorders and Cancer - PowerPoint PDF

The Integument ary System Dr. Kennedy Oakland University  Integumentary System- key points 1. The skin is the largest organ of the body and is made up of the epidermis, dermis, and hypodermis (subcutaneous) layers. 2. The epidermis is the outer layer of skin. It does not contain vascular stru...

The Integument ary System Dr. Kennedy Oakland University  Integumentary System- key points 1. The skin is the largest organ of the body and is made up of the epidermis, dermis, and hypodermis (subcutaneous) layers. 2. The epidermis is the outer layer of skin. It does not contain vascular structures and is made up of five distinct layers. Each layer is characterized by the type of cells and tissues which it consists of. 3. The dermis is the middle layer of the skin. Nerves and blood vessels pass through this layer, and there are millions of sensory receptors in the dermis. The dermis is further divided into two layers, which are papillary layer and reticular layer. 4. The hypodermis is the innermost layer of the skin but is actually not a part of the skin. Instead, it connects the skin to the rest of the body and has skin-like properties, including a loose, fibrous tissue. 5. Skin accessories are parts of the integumentary system but are not actually skin, and include hair follicles, sebaceous glands, sweat glands, and nails. Copyright © 2017, Elsevier Inc. All rights r 2 eserved. Skin Function Acts as first line of defense Prevents excessive fluid loss Controls body temperature Active in sensory perception Synthesizes vitamin D Copyright © 2017, Elsevier Inc. All rights r 4 eserved. Review of Normal Skin Layers of the skin Epidermis—avascular Dermis Subcutaneous tissue (hypodermis)  Epidermis Five layers—vary in thickness Keratin Waterproofing of the skin Melanin Skin pigment—determines skin color Production depends on multiple genes and environment Albinism Lack of melatonin production Vitiligo Small areas of hypopigmentation Melasma Patches of darker skin Dermis Connective tissue Contains elastic and collagen fibers Flexibility and strength of the skin Contains nerves and blood vessels Includes sensory receptors for: Pressure Touch Pain Heat Cold Layers of Dermis Papillary Layer Thin, uppermost layer of the dermis Projects papillae (projectile bumps) into the epidermis Forms ridges (called friction ridges) on the palms, fingers, toes, and soles Reticular Layer Densely fibrous lower layer of the dermis Contains elastic fibers Copyright © 2017, Elsevier Inc. All rights r 8 eserved. Hypodermis The hypodermis, sometimes called the subcutaneous layer, is the deepest layer of the skin. It is located underneath the dermis. The hypodermis is made up of: Connective tissue Fat cells Macrophages Fibroblasts (cell that contributes to formation of connective tissue) Blood vessels Nerves The base of many appendages Copyright © 2017, Elsevier Inc. All rights r 9 eserved. Appendages of the Skin Hair follicles Stratum basale—hair-producing Arrector pili muscle associated with hair follicle Sebaceous glands Produce sebum Secretion increases at puberty—influence of sex hormones Sweat glands Eccrine—all over body Apocrine Axillae, scalp, face, external genitalia Resident (Normal) Flora of the Skin Mixed flora—components differ in various areas of the body. Microbes also reside under the fingernails, in hair follicles, and in glands. Opportunistic infections may occur because of injury or other inflammatory lesion. Infection may spread systemically from skin lesions. Disorders of the Integument 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 Skin Lesions: Assessment Types of lesions Location Length of time lesion has been present Changes occurring over time Physical appearance Color Elevation Texture Type of exudate Presence of pain or pruritus (itching)  Clinical Manifestations of Skin Dysfunction Primary Lesions Secondary Lesions Macule Scale Papule Lichenification Patch (leathery feeling) Plaque Keloid Wheal Scar Nodule Excoriation Tumor Fissure Vesicle Erosion Bulla Ulcer Pustule Atrophy Cyst Telangiectasia 15 Disorders of the Skin Inflammatory disorders Eczema and dermatitis (used interchangeably) are the most common inflammatory disorders of the skin Characterized by: Pruritus Lesions with indistinct borders Epidermal changes When chronic, the skin becomes thickened, leathery, and hyperpigmented from recurrent irritation and scratching Copyright © 2017, Elsevier Inc. All rights r 16 eserved.  Inflammatory Disorders Allergic contact dermatitis Caused by T-cell–mediated or delayed hypersensitivity The allergen comes in contact with the skin, binds to a carrier protein to form a sensitizing antigen; Langerhans cells process the antigen and carry it to T cells, which become sensitized to the antigen Manifestations Erythema Swelling Pruritus Vesicular lesions 17 Inflammatory Disorders Stasis dermatitis Occurs in the legs as a result of venous stasis and edema Sequence of events Erythema Pruritus Scaling Petechiae Hyperpigmentation Ulcerations 18 Papulosquamous Disorders Psoriasis Chronic, relapsing, proliferative, inflammatory skin disorder Caused by complex interactions between macrophages, fibroblasts, dendritic cells, natural killer cells, T-helper, and regulatory T cells Shows evidence of dermal and epidermal thickening 20 Lupus erythematosus Systemic, inflammatory, autoimmune disease with cutaneous manifestations Discoid lupus erythematosus Restricted to the skin Photosensitivity Butterfly pattern over the nose and cheeks Related to genetic and environmental factors and an altered immune response Lesions persist for months and then resolve spontaneously or atrophy 21 Vesiculobullous Diseases Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Same disease at different points on continuum Type IV hypersensitivity reactions to drugs Medical emergencies Bullous lesions form erosions and crusts Mucosal involvement Mouth, air passages, esophagus, urethra, conjunctiva May cause blindness Difficulty eating, breathing, and urinating Bacterial Infections Folliculitis Infection of hair follicle Furuncles Abscesses of hair follicles Carbuncles Collection of furuncles Cellulitis Infection of the dermis and subcutaneous tissue Erysipelas Acute superficial infection of the upper dermis  Cellulitis Cellulitis occurs when certain types of bacteria enter the skin through a cut or crack. Staphylococcus and Streptococcus bacteria can cause this infection. Infection of the dermis and subcutaneous tissue Pain, warmth, rapidly spreading erythema, edema Bacterial Infections Impetigo Superficial infection of the skin caused by coagulase-positive Staphylococcus or β-hemolytic streptococci Lyme disease Multisystem inflammatory disease caused by Borrelia burgdorferi transmitted by Ixodes ticks Symptoms of the disease occur in three stages Localized infection Disseminated infection Post-Lyme disease syndrome (chronic Lyme disease) Viral Infections Herpes simplex virus HSV-1 and HSV-2 Transmitted by contact with infected saliva Associated with oral infections or infection of the cornea, mouth, and orolabia—HSV-1 Lesions for HSV-1 appear as clusters of inflamed and painful vesicles on erythematous base Genital infections are more commonly caused by HSV-2 Viral Infections Herpes zoster (shingles) and varicella (chickenpox) Caused by the same herpesvirus—varicella-zoster virus (VZV) Primary infection followed years later by activation of the virus to cause herpes zoster (shingles) Virus remains latent in trigeminal and dorsal root ganglia Warts Benign lesions caused by the human papillomavirus (HPV) Common warts occur most often in children and usually on the fingers Plantar warts are usually on pressure points on bottom of feet Condylomata acuminata Venereal warts Copyright © 2017, Elsevier Inc. All rights reserved. 29 Fungal Infections Dermatophytes Fungi causing superficial skin lesions Mycoses Fungal disorders Mycoses caused by dermatophytes are termed tinea Tinea capitis (scalp) Tinea manus (hand) Tinea pedis (athlete’s foot) ----- Tinea corporis (ringworm) Tinea cruris (groin, jock itch) Tinea unguium (nails) or onychomycosis 30 Fungal Infections Candidiasis Caused by Candida albicans Normally found on the skin, mucous membranes, in the GI tract, and in the vagina Candida albicans can change from a commensal organism to a pathogen Local environment of moisture and warmth Systemic administration of antibiotics Pregnancy Diabetes mellitus Cushing disease Debilitated states Age younger than 6 months Immunosuppression Neoplastic diseases 31 Wound Cultures Diagnostic test to differentiate the bacteria or fungus in a wound Sample of wound is taken from the skin, tissue, or fluid and looked at under a microscope If nothing grows, the culture is negative If there is growth, the culture is positive and guides treatment 32 Vascular Disorders Cutaneous vasculitis Inflammation of the blood vessel wall Results from immune complexes in the small blood vessels Develops from drugs, allergens, or viral infections Lesions Palpable purpura progressing to hemorrhagic bullae with necrosis and ulceration 33 Vascular Disorders Urticaria Circumscribed area of raised erythema and edema of the superficial dermis Associated with type I hypersensitivity reactions to allergens Histamine release causes endothelial cells of the skin to contract Causes leakage of fluid from the vessels Most lesions resolve spontaneously within 24 hours, but new lesions may appear 34  Vascular Disorders (Cont.) Scleroderma Localized or systemic Causes thickening (sclerosis) of the skin Associated with several antibodies Localized scleroderma is differentiated from the systemic form of the disease Skin is hard, hypopigmented, taut, shiny, and tightly connected to the underlying tissue Progression to body organs may occur 35 Pressure Ulcers/Injuries Pressure ulcers result from any unrelieved pressure on the skin, causing underlying tissue damage: Pressure Shearing forces Friction Moisture 36 Pressure Ulcers Develop over bony prominences Pressure distorts capillaries and occludes blood supply Can develop in soft tissues Unrelieved pressure causes endothelial cells lining capillaries to become disrupted with platelet aggregation Pressure Ulcers: Staging 1. Nonblanchable erythema of intact skin sores are not open wounds. The skin may be painful, but it has no breaks or tears. The skin appears reddened and does not blanch (lose color briefly when you press your finger on it then remove your finger) 2. Partial-thickness skin loss involving epidermis or dermis skin usually breaks open, wears away, or forms an ulcer, which is usually tender and painful. The sore expands into deeper layers of the skin. It can look like a scrape (abrasion) or a shallow crater in the skin. Sometimes this stage looks like a blister filled with clear fluid. At this stage, some skin may be damaged beyond repair or may die. 3. Full-thickness skin loss involving damage or loss of subcutaneous tissue sore gets worse and extends into the tissue beneath the skin, forming a small crater. Fat may show in the sore, but not muscle, tendon, or bone. 4. Full-thickness skin loss with exposure of muscle, bone, or supporting structures injury is very deep, reaching into muscle and bone and causing extensive damage. Damage to deeper tissues, tendons, and joints may occur. 38 Pressure Ulcers: Staging Suspected deep tissue injury—discolored (purple or maroon) intact skin or blood-filled blister In some cases, a deep pressure injury is suspected but can't be confirmed. When there isn't an open wound but the tissues beneath the surface have been damaged, the sore is called a deep tissue injury (DTI). The area of skin may look purple or dark red, or there may be a blood-filled blister. Unstageable—full-thickness tissue loss with base of ulcer covered by slough or eschar, or both the sore is covered by a thick layer of other tissue and pus that may be yellow, gray, green, brown, or black. The provider cannot see the base of the sore to determine the stage. Pressure Ulcers Prevention Preventive techniques Frequent skin assessment Repositioning Pressure reduction, removal, and distribution Elimination of moisture Cleanliness MOVE DECREASE PROLONG SITTING OR LAYING KEEP MOVING 41 Burns  Burns First degree Epidermis only Second degree Superficial partial thickness Epidermis and some dermis Deep partial thickness Epidermis and dermis, leaving only skin appendages Third degree Full thickness Epidermis, dermis, and underlying subcutaneous tissue Fourth degree Full-thickness and deeper tissue Epidermis, dermis, and underlying subcutaneous tissue, tendons, muscle, and bone 43 Burns Estimating Burn Injury Total body surface area estimation Rule of nines Modified Lund and Browder chart 45  Burn Shock Burn shock is a condition consisting of a hypovolemic cardiovascular component and a cellular component. Copyright © 2017, Elsevier Inc. All rights r 46 eserved.  Burns (Cont.) Cardiovascular and systemic response Hallmark of burn shock is decreased cardiac contractility and decreased cardiac output with inadequate capillary perfusion Fluid and protein movement out of the vascular compartment results in an elevated hematocrit and white blood cell count and hypoproteinemia Irreversible shock and death if not treated immediately Cellular response to burn injury Transmembrane potential disruption Impairs the sodium-potassium pump Increased intracellular sodium and water Decreased potassium 47  Burns (Cont.) Metabolic response to Immunologic response to burn injury: burn injury: Immediate, prolonged, and severe Flow phase End result is immunosuppression Systemic Altered white blood cells hypermetabolic Impaired phagocytosis Abnormal cellular and humoral immunity response Potentially fatal wound sepsis Can persist for a year or longer following a Evaporative water loss burn Loss of the skin’s barrier function and Inflammatory response ability to regulate evaporative water loss with local activation and Skin and the lungs have increased loss of recruitment of water as a result of hypermetabolism and inflammatory cells at hyperventilation Replacement is mandatory the site of injury Hypermetabolism 48 Burns (Cont.) Elements of survival of major burn Provision of adequate fluids and nutrition Meticulous management of wounds with early surgical excision and grafting Aggressive treatment of infection or sepsis Promotion of thermoregulation 49 Skin Cancer Benign Tumors Seborrheic keratosis Benign proliferation of cutaneous basal cells Keratoacanthoma Benign, self-limiting tumor of squamous cell differentiation from hair follicles Actinic keratosis Premalignant lesion composed of aberrant proliferations of epidermal keratinocytes Nevi (moles or birthmarks) Benign pigmented or nonpigmented lesions Basal Cell Carcinoma Most common cancer in the world Numerous subtypes Grows slowly, often ulcerates, develop crusts, and is firm to the touch Metastasis is rare 52 Squamous Cell Carcinoma Tumor of the epidermis Second most common human cancer In situ or invasive Rarely invade surrounding tissue 53 Melanoma Malignant tumor of the skin originating from melanocytes Most serious skin cancer Lesions may be red, black, blue, gray, white 54 Disorders of the Hair Alopecia Loss of hair from the head or body Androgenic alopecia Localized hair loss occurring in about 80% of men Genetically predisposed response to androgens Androgen-sensitive and androgen-insensitive follicles Female-pattern alopecia Progressive thinning and loss of hair over the central part of the scalp No loss of hair along the frontal hairline Hirsutism Abnormal growth and distribution of hair on the face, body, and pubic area in a male pattern that occurs in women Androgen-sensitive areas 55 Disorders of the Nail Paronychia Acute or chronic infection of the cuticle Onychomycosis Fungal or dermatophyte infection of the nail plate 56