Chapter 46 Disorders of Skin Integrity and Function

Skin Infections Superficial fungal infections Ringworm, athlete’s foot Attack the keratinized (dead) cells Inflammatory reaction to toxins causes most signs and symptoms Deep fungal infections Candidiasis, sporotrichosis Attack living tissue May attack other organs

Bacterial Skin Infections Impetigo May lead to post- streptococcal hypersensitivity reactions These can cause glomerulonephritis

Viral Skin Infections Verrucae (warts) Benign neoplasms (papillomas) Herpes simplex (cold sores) Herpes zoster (shingles) Herpes invades dorsal root ganglia Caused when chickenpox herpesvirus is reactivated Travels out nerve to skin and causes a new inflammation

Question Which of the following microbes cause warts? Fungus Virus Bacteria Any of the above may cause warts.

Answer Virus Warts are caused by viruses; they’re benign neoplasms (abnormal tissue growths).

Scenario Mrs. K is worried about her complexion… She says she always had good skin, but now her face itches and burns on the right side, and there are red lumps on one side of her forehead Question What are the possible causes?

Acne Disorder of sebaceous glands Related to: Hormonal stimulation of sebaceous glands Increased number of sebaceous cells Increased sebum production Inflammatory response to bacteria in sebum

Allergic and Hypersensitivity Dermatoses Type I allergies Atopic eczema Urticaria (hives)

Type I Allergies Type I allergies are mediated by IgE Discussion What cells must be involved in this process? On the first exposure to the allergen? On repeated exposure? When the allergen binds to IgE? What inflammatory mediators are involved? How?

Question Which chemical mediator is released by mast cells as part of the inflammatory response? Histamine Leukotriene Cytokine All of the above

Answer Histamine Histamine (stored in mast cells) is one of the first substances to be released during the inflammatory response. Histamine release results in bronchoconstriction, mucosal edema, and increased mucus production.

Autoimmune Urticaria In autoimmune urticaria, the client creates anti-IgE antibodies Discussion How would this cause hives? How would a deficiency in complement inhibitor cause hives? Why would antihistamines help? Why would corticosteroids help?

Drug-Induced Skin Eruptions Erythema multiforme Occurs after herpes simplex; self-limiting Stevens-Johnson syndrome Skin detaches from body surface; <10% of body affected Toxic epidermal necrolysis >30% of epidermis detaches 30%–35% mortality rate

Papulosquamous Dermatoses Psoriasis Pityriasis rosea Lichen planus

Psoriasis Activated T cells growth attract factors neutrophils and monocytes keratinocytes enter and blood the vessels grow papules create create papules inflammation

Burns First-degree: outer layers of epidermis Second-degree: epidermis and dermis Partial-thickness: only part of dermis Full-thickness: entire dermis Third-degree full-thickness Extends into subcutaneous tissue May damage muscle, bone, blood vessels

Scenario Mr. D was boiling water and the pot tipped over on him… He has painful, bright pink, blistering burns over most of his left arm and chest Question How would you categorize this burn?

Scenario (cont.) His pulses are weak Bowel sounds are absent Mr. D's burns are pink but the rest of his body looks pale, and he has a rapid heart rate… His pulses are weak Bowel sounds are absent Respiration is rapid Question What has caused these signs?

Complications of Burns Burn shock Respiratory system dysfunction Hypermetabolic response Renal insufficiency Gastric ulceration Sepsis Constriction of areas under circumferential burns Systemic infection

Scenario A woman was severely burned and she has been in the hospital for eight days Question Why would she be developing: Increased urine production? Weight loss? Increased temperature? GI bleeding?

Question Treatment for third-degree burn patients includes all but which of the following? Fluid replacement Removal of dead tissue/eschar Antibiotics Aloe

Answer Aloe Patients suffering from third-degree (full thickness) burns lose fluid through the skin and are prone to infection. They must receive fluid replacement and antibiotics to fight or prevent infection. Dead tissue (eschar) must be removed daily (debridement) in order to prevent infection. Because third-degree burns destroy the epidermis, the application of topical aloe would serve no purpose.

Pressure Sores External Shear pressure bends blood obstructs blood flow Friction vessels ischemia to skin damages dermis/ tissue damage epidermis interface

Ultraviolet radiation melanin oxidized - TAN hits melanocytes more melanin produced - delayed tanning some UV reaches lower skin layers immune DNA cells damage damaged inflammatory mediators released sunburn

Sun Exposure Sun exposure increases the risk of skin cancer Cumulative sun exposure increases risk of: Basal cell carcinoma Squamous cell carcinoma Severe sun exposure with blistering increases risk of: Malignant melanoma

Malignant Melanoma Cancers arising from melanocytes Asymmetry Border irregularity Color variegation Diameter >0.6 cm Evolving change over time

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Types of Melanomas 70% are superficial spreading Raised edges; grow horizontally and vertically Ulcerate and bleed 15%–30% are nodular Dome-shaped, blue-black 4%–10% are lentigo maligna Slow growing, flat 2%–4% acral lentiginous On palms, soles, nail beds, mucous membranes

Question Which type of skin cancer is associated with the worst prognosis? Basal cell Squamous cell Malignant melanoma Ependymal cell

Answer Malignant melanoma Malignant melanoma begins in the melanocytes, and possesses all of the characteristic features associated with cancer (asymmetry, irregular border, many colors, and a diameter >0.6 cm) as defined by the American Cancer Society. Basal cell cancer has the best prognosis, and squamous cell cancer has a good prognosis as long as it is detected early.

Skin Conditions of Infancy Birthmarks Diaper dermatitis Prickly heat Cradle cap Infectious disease rashes Roseola (herpesvirus) Rubeola (measles) Rubella (German measles) Varicella (chickenpox)

Skin Disorders of the Elderly Actinic (solar) damage Keratoses: premalignant lesions Lentigines: liver spots Vascular lesions Angiomas Telangiectases Venous lakes