1. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.1 Structure, Function, and Disorders of the Integument Chapter 39

2. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.2 Layers of the Skin  Epidermis  Dermis  Hypodermis

3. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.3 Layers of the Skin (cont’d)

4. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.4 Layers of the Skin (cont’d)  Dermal appendages:  Nails  Hair  Sebaceous glands  Eccrine and apocrine sweat glands  Blood supply  Papillary capillaries

5. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.5 Nails

6. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.6 Aging and Skin Integrity  The integumentary system reflects numerous changes from genetic and environmental factors  The skin becomes thinner, drier, wrinkled, and demonstrates a change in pigmentation  Shortening and decrease in the number of capillary loops  Fewer melanocytes and Langerhans cells

7. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.7 Aging and Skin Integrity (cont’d)  The integumentary system reflects numerous changes from genetic and environmental factors (cont’d)  Atrophy of the sebaceous, eccrine, and apocrine glands  Changes in hair color  Fewer hair follicles and growth of thinner hair

8. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.8 Clinical Manifestations of Skin Dysfunction  Macule  Papule  Patch  Plaque  Wheal  Nodule  Tumor  Vesicle  Bulla  Pustule  Cyst  Telangiectasia  Scale  Lichenification  Keloid  Scar  Excoriation  Fissure  Erosion  Ulcer  Atrophy

9. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.9 Pressure Ulcers  Pressure ulcers result from any unrelieved pressure on the skin, causing underlying tissue damage  Pressure  Shearing forces  Friction  Moisture

10. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.10 Pressure Ulcers (cont’d)

11. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.11 Pressure Ulcers (cont’d)  Stages:  I. Nonblanchable erythema of intact skin  II. Partial-thickness skin loss involving epidermis or dermis  III. Full-thickness skin loss involving damage or loss of subcutaneous tissue  IV. Full-thickness skin loss with damage to muscle, bone, or supporting structures

12. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.12 Keloids  Elevated, rounded, and firm  Clawlike margins that extend beyond the original site of injury  Excessive collagen formation during dermal connective tissue repair  Common in darkly pigmented skin types and burn scars  Type III collagen is increased

13. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.13 Keloids (cont’d)

14. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.14 Pruritus  Itching  Most common symptom of primary skin disorders  Itch is carried by specific unmyelinated C- nerve fibers and is triggered by a number of itch mediators  The CNS can modulate the itch response

15. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.15 Pruritus (cont’d)  Pain stimuli at lower intensities can induce itching  Chronic itching can result in infections and scarring due to persistent scratching

16. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.16 Disorders of the Skin  Inflammatory disorders  The most common inflammatory disorders of the skin are dermatitis or eczema  There are various types of dermatitis  The disorders are generally characterized by: Pruritus Lesions with indistinct borders Epidermal changes

17. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.17 Inflammatory Disorders  Allergic contact dermatitis  Caused by a hypersensitivity type IV reaction  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

18. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.18 Allergic Contact Dermatitis

19. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.19 Inflammatory Disorders  Atopic dermatitis  Type I hypersensitivity: activation of mast cells, eosinophils, T-lymphocytes, and other inflammatory cells  Causes red, weeping crusts and chronic inflammation, lichenification

20. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.20 Inflammatory Disorders (cont’d)  Irritant contact dermatitis  Nonimmunologic inflammation of the skin  Chemical irritation from acids or prolonged exposure to irritating substances  Symptoms similar to allergic contact dermatitis  Treatment: remove stimulus

21. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.21 Inflammatory Disorders (cont’d)  Stasis dermatitis  Occurs in the legs as a result of venous stasis, edema, and vascular trauma  Sequence of events: Erythema Pruritus Scaling Petechiae Ulcerations

22. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.22 Inflammatory Disorders (cont’d)  Seborrheic dermatitis  Inflammation of the skin involving the scalp, eyebrows, eyelids, nasolabial folds, and ear canals  Scaly, white, or yellowish plaques

23. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.23 Stasis and Seborrheic Dermatitis

24. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.24 Papulosquamous Disorders  Psoriasis  Chronic, relapsing, proliferative skin disorder  T cell immune- mediated skin disease  Scaly, thick, silvery, elevated lesions, usually on the scalp, elbows, or knees caused by a high rate of mitosis in the basale layer

25. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.25 Papulosquamous Disorders (cont’d)  Psoriasis (cont’d)  Shows evidence of dermal and epidermal thickening  Epidermal turnover goes from 26 to 30 days to 3 to 4 days  Cells do not have time to mature or adequately keratinize

26. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.26 Psoriasis

27. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.27 Papulosquamous Disorders  Psoriasis (cont’d)  Plaque psoriasis  Inverse psoriasis  Guttate psoriasis  Pustular psoriasis  Erythrodermic psoriasis

28. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.28 Papulosquamous Disorders (cont’d)

29. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.29 Papulosquamous Disorders (cont’d)  Pityriasis rosea  Benign, self-limiting inflammatory disorder  Usually occurs during the winter months  Herald patch Circular, demarcated, salmon-pink, 3- to 4-cm lesion

30. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.30 Papulosquamous Disorders (cont’d)

31. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.31 Papulosquamous Disorders (cont’d)  Lichen planus  Benign, inflammatory disorder of the skin and mucous membranes  Unknown origin, but T cells, adhesion molecules, inflammatory cytokines, and antigen presenting cells are involved  Nonscaling, violet-colored, 2- to 4-mm lesions  Wrists, ankles, lower legs, genitalia

32. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.32 Lichen Planus

33. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.33 Papulosquamous Disorders  Acne vulgaris  Inflammatory disease of the pilosebaceous follicles  Acne rosacea  Inflammation of the skin that develops in adulthood  Lesions Erythematotelangiectatic, papulopustular, phymatous, and ocular Associated with chronic, inappropriate vasodilation resulting in flushing and sensitivity to the sun

34. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.34 Papulosquamous Disorders (cont’d)  Lupus erythematosus  Inflammatory, autoimmune disease with cutaneous manifestations  Discoid lupus erythematosus Restricted to the skin Photosensitivity Butterfly pattern over the nose and cheeks  Systemic lupus erythematosus

35. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.35 Discoid Lupus Erythematosus

36. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.36 Vesiculobullous Disorders  Pemphigus  Rare, chronic, blister-forming disease of the skin and oral mucous membranes  Blisters form in the deep or superficial epidermis  Autoimmune disease caused by circulating IgG autoantibodies The antibodies are against the cell surface adhesion molecule, desmoglein in the suprabasal layer of the epidermis

37. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.37 Vesiculobullous Disorders (cont’d)  Pemphigus (cont’d)  Tissue biopsies demonstrate autoantibody presence  Types: Pemphigus vulgaris (severe) Pemphigus foliaceus Pemphigus erythematosus

38. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.38 Vesiculobullous Disorders (cont’d)  Bullous pemphigoid  More benign disease than pemphigus vulgaris  Bound IgG and blistering of the subepidermal skin layer  Subepidermal blistering and eosinophils distinguish pemphigoid from pemphigus

39. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.39 Bullous Pemphigoid

40. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.40 Vesiculobullous Disorders  Erythema multiforme  Acute, recurring disorder of the skin and mucous membranes  Associated with allergic or toxic reactions to drugs or microorganisms  Caused by immune complexes formed and deposited around dermal blood vessels, basement membranes, and keratinocytes

41. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.41 Vesiculobullous Disorders (cont’d)  Erythema multiforme (cont’d)  “Bull’s-eye” or target lesion Erythematous regions surrounded by rings of alternating edema and inflammation  Bullous lesions form erosions and crusts when they rupture  Affects the mouth, air passages, esophagus, urethra, and conjunctiva  Severe forms: Stevens-Johnson syndrome (bullous form) Toxic epidermal necrolysis

42. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.42 Infections  Bacterial infections:  Folliculitis  Furuncles  Carbuncles  Cellulitis  Erysipelas  Impetigo

43. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.43 Furuncle

44. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.44 Infections  Viral infections  Herpes zoster and varicella

45. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.45 Herpes Simplex Virus

46. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.46 Warts  Benign lesions caused by the human papillomavirus (HPV)  Diagnosed by visualization  Condylomata acuminata  Venereal warts

47. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.47 Fungal Infections  Fungi causing superficial skin lesions are called dermatophytes  Fungal disorders are called mycoses; mycoses caused by dermatophytes are termed tinea  Tinea capitis (scalp)  Tinea pedis (athlete’s foot)  Tinea corporis (ringworm)  Tinea cruris (groin, jock itch)  Tinea unguium (nails) or onychomycosis

48. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.48 Tinea Pedis

49. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.49 Fungal Infections  Candidiasis  Caused by Candida albicans  Normally found on the skin, 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

50. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.50 Vascular Disorders  Cutaneous vasculitis  Results from immune complexes in the small blood vessels Develops from drugs, bacterial infections, viral infections, or allergens  Lesions Palpable purpura progressing to hemorrhagic bullae with necrosis and ulceration

51. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.51 Vascular Disorders (cont’d)  Urticaria  Caused by type I hypersensitivity reactions to allergens  Histamine release causes endothelial cells of the skin to contract Causes leakage of fluid from the vessels  Treatment Antihistamines and steroids

52. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.52 Vascular Disorders (cont’d)  Scleroderma  Sclerosis of the skin that can progress to the internal organs  The disease is associated with several antibodies  Lesions exhibit massive deposits of collagen with inflammation, vascular changes, and capillary dilation  Skin is hard, hypopigmented, taut, and tightly connected to underlying tissue

53. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.53 Vascular Disorders (cont’d)  Scleroderma (cont’d)  Facial skin becomes very tight  Fingers become tapered and flexed; nails and fingertips can be lost from atrophy  Mouth may not open completely  50% of patients die within 5 years

54. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.54 Scleroderma

55. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.55 Insect Bites  Bees  Mosquitoes  Flies

56. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.56 Benign Tumors  Seborrheic keratosis  Keratoacanthoma  Actinic keratosis  Nevi (moles)

57. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.57 Seborrheic Keratosis

58. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.58 Cancer  Basal cell carcinoma  Squamous cell carcinoma  Malignant melanoma  Kaposi sarcoma

59. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.59 Basal Cell Carcinoma

60. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.60 Squamous Cell Carcinoma

61. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.61 Malignant Melanoma

62. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.62 Kaposi Sarcoma

63. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.63 Burns  Partial-thickness burns  First degree  Superficial and deep partial  Second degree  Full-thickness burns  Third degree  “ Rule of nines”

64. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.64 Superficial Partial-Thickness Burn

65. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.65 Axillary Burn Scar Contracture

66. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.66 Deep Partial-Thickness Burn

67. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.67 Full-Thickness Burn

68. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.68 Estimating Burn Injury

69. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.69 Burns

70. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.70 Hypertrophic Scarring

71. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.71 Cultured Epithelial Autograft

72. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.72 Frostbite  Skin injury caused by exposure to extreme cold  Usually affects fingers, toes, ears, nose, and cheeks  The “burning reaction” is caused by alternating cycles of vasoconstriction and vasodilation  Inflammation and reperfusion are both part of the pathophysiology

73. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.73 Disorders of the Hair  Male-pattern alopecia  Genetically predisposed response to androgens  Androgen-sensitive and androgen-insensitive follicles

74. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.74 Disorders of the Hair (cont’d)  Female-pattern alopecia  Associated with elevated levels of the serum adrenal androgen dehydroepiandrosterone sulfate  No loss of hair along the frontal hairline

75. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.75 Disorders of the Hair (cont’d)  Alopecia areata  Autoimmune T cell-mediated inflammatory disease against hair follicles that results in baldness  Hirsutism  Androgen-sensitive areas Abnormal growth and distribution of hair on the face, body, and pubic area in a male pattern that occurs in women

76. Mosby items and derived items © 2012 Mosby, Inc., an imprint of Elsevier Inc.76 Disorders of the Nail  Paronychia  Acute or chronic infection of the cuticle  Onychomycosis  Fungal or dermatophyte infection of the nail plate