Skin Chapter Goals

2/4/2016 Chapter 16: Skin  Find this out on page 650 in your book:  What the name for the system that includes skin?  How much does our skin weigh?  How much surface area does it cover? Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1Chapter Goals  Name the layers of the skin and the accessory structures associated with the skin.  Build medical words using the combining forms that are related to the specialty of dermatology.  Identify lesions, signs, and symptoms, and pathologic conditions that relate to the skin. Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21 2/4/2016 Chapter Goals  Describe laboratory tests and clinical procedures that pertain to the skin and recognize relevant abbreviations.  Apply your new knowledge to understanding medical terms in their proper contexts, such as medical reports and records. Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3Introduction ● the skin and its accessory structures (hair, nails and glands) make up the integumentary system of the body ● weighs 8-10 lb ● covers 22 square feet Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 42 2/4/2016 Functions of Skin  provides protective membrane - guards the deeper tissues against excessive loss of water, salts and heat - protects against pathogens  glands lubricate and cool the skin  receptor for sensations (pain, temp, pressure and touch)  helps maintain body temperature (thermoregulation) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5Anatomy of the Skin Epidermis: outermost, thin cellular membrane - contains keratin Dermis: dense, fibrous, connective tissue layer - contains collagen Subcutaneous tissue (hypodermis): thick, fat- containing tissue Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 63 2/4/2016 Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7Acessory Organs of the Skin HAIR: cells filled with the hard protein; keratin  Hair follicles: shafts that hold the hair  Five million hairs on body; 100,000 on head  Melanocytes at the root form the color  Grow .5 inch (1.3 cm) per month  Cutting does not affect growth Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 84 2/4/2016 Accessory Organs of the Skin (cont’d) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9Accessory Organs of Skin (cont’d) NAILS: hard keratin plates covering toes and fingers  lunula  cuticle  paronychium Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10 5 2/4/2016 Accessory Organs of Skin (cont’d) GLANDS: sebaceous and sweat  Sebaceous glands secrete oily sebum into hair follicle to lubricate.  Sweat glands secrete into pores to moisten and cool.  Both are subject to bacterial growth. Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11 Accessory Organs of Skin (cont’d)  Sebaceous gland:  Oil secreting gland in the dermis that is associated with hair follicles  Eccrine sweat gland:  Most numerous sweat producing exocrine gland  Apocrine sweat gland.  Sweat gland located in the axilla (armpit) and genital areas Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12 6 2/4/2016 Colors – combining forms ● memorize this table Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13 Skin Pathology CUTANEOUS LESIONS ● a lesion is an area of abnormal tissue anywhere on the body - it may be caused by trauma or disease crust - collection of dried serum and cellular debris (scab, eczema, impetigo, seborrhea) cyst - thick-walled, closed sac / pouch containing fluid or semisolid material erosion - wearing away of the epidermis (dermoepidermal junction) - occur due to inflammation Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14 or injury 7 2/4/2016 Skin Pathology CUTANEOUS LESIONS fissure - grove or crack-like sore macule - flat lesion < 1cm in diameter (freckles, tattoo marks, flat moles) nodule - solid, round or oval elevated lesion > 1cm in diameter (enlarge lymph node or solid growths) papule - small (< 1cm), solid elevation of the skin (pimples - if confluent called plaques) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15 Skin Pathology CUTANEOUS LESIONS polyp - growth extending from the surface of a mucous membrane (type of papule commonly found in nose / sinuses, colon, bladder and uterus) pustule - papule containing pus (small abscess) ulcer - open sore on the skin or mucous membranes (deeper than an erosion) vesicle - small collection (papule) of clear fluid (serum); blister (vesicles form in burns, allergies, dermatitis) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16 8 2/4/2016 Skin Pathology CUTANEOUS LESIONS wheal - smooth, edematous (swollen) papule or plaque that is redder or paler than the surrounding skin (often accompanied by itching and are seen in hives, anaphylaxis and insect bites) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17 Cutaneous Lesions (p 662) 1. Crust 2. Cyst 3. Erosion 4. Fissure 5. Macule 6. Nodule 7. Papule 8. Polyp 9. Pustule 10.Ulcer 11.Vesicle 12.Wheal Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18 9 2/4/2016 Signs and Symptoms alopecia: absence of hair where it normally grows  alopecia or baldness may be hereditary (male pattern baldness) or it may be caused by disease, injury or treatment (chemotherapy)  alopecia areata - autoimmune disease - hair falls out in patches without scarring or inflammation Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19 Signs and Symptoms ecchymosis: blue-black marks (bruise) on the skin  caused by hemorrhages into the skin from injury or spontaneous leaking of blood from vessels Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20 10 2/4/2016 Signs and Symptoms petechia: small pinpoint hemorrhage  smaller versions of ecchymoses - both ecchymoses and petechiae are forms of purpura (bleeding into the skin) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21 Signs and Symptoms pruritus - itching  symptom associated with most forms of dermatitis  arises from stimulation of the nerves in the skin urticaria: acute allergic reaction with red, round wheals on skin  commonly due to food allergies (shelfish and strawberries)  localized edema occurs as well Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22 11 2/4/2016 ABNORMAL CONDITIONS acne: papular and pustular eruption of skin with increased production of sebum  acne vulgaris (ordinary) is a buildup of sebum and keratin in the pores of the skin Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23 ABNORMAL CONDITIONS burns: injury to tissue due to heat, chemical, electric shock, lightning or radiation.  first-degree burn - superficial epidermal lesions, erythema, hyperesthesia and no blisters  second-degree burn (partial thickness) - epidermal and dermal lesions, erythema, blisters and hyperesthesia second degree burn Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24 12 2/4/2016 ABNORMAL CONDITIONS burns: injury to tissue due to heat, chemical, electric shock, lightning or radiation  third-degree burns (full thickness) - epidermis and dermis are destroyed (necrosis) and subcutaneous layer damaged, leaving charred, white tissue third degree burn Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 25 ABNORMAL CONDITIONS  cellulitis: diffuse acute infection of skin marked by local heat, redness, pain and swelling  abscess formation and tissue destruction can occur without appropriate antibiotic therapy  eczema: inflammation of skin with erythematous, papulovesicular lesions caused by allergy  chronic or acute atopic dermatitis is accompanied by pruritus  treatment usually corticosteriods Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 26 13 2/4/2016 ABNORMAL CONDITIONS  exanthematous viral diseases: rash (exanthem) of the skin due to virus  examples: rubella (German measles), rubeola (measles) and varicella (chicken pox) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 27 ABNORMAL CONDITIONS  gangrene: death of tissue associated with loss of blood supply  ischemia from injury, inflammation, frostbite, diabetes or arteriosclerosis can lead to necrosis followed by bacterial infection and putrefaction  impetigo: bacterial inflammatory skin disease characterized by vesicles, pustules and crusted-over lesions  contagious pyoderma caused by Staphylococci or Streptococci  treatment with systemic antibiotics and cleaning lesions Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 28 14 2/4/2016 ABNORMAL CONDITIONS  psoriasis: chronic recurrent dermatosis marked by itchy, scaly, red plaques covered by silvery gray scales  not infectious or contagious but autoimmune - caused by in increased rate of growth of the basal layer of epidermis  scabies: contagious, parasitic infection (mites) of the skin with intense pruritus Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 29 ABNORMAL CONDITIONS  scleroderma: chronic, progressive disease of skin and internal organs with hardening and shrinking of connective tissue (autoimmune)  fibrous, scar-like tissue forms in the skin, heart, lungs, kidneys and esophagus  palliative treatment - immunosuppressives / antiinflammatory agents, physical therapy  immunosuppressives Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 30 15 2/4/2016 ABNORMAL CONDITIONS  systemic lupus erythematosus (SLE): chronic autoimmune disease of collagen in the skin, joints and internal organs  “butterfly” pattern of redness over cheeks and nose  primarily affects females  treatment includes corticosteroids and Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 31 ABNORMAL CONDITIONS  tinea - infection of the skin caused by a fungus  tinea corporis (ringworm) - infection is in a ring-like pattern - highly contagious with severe pruritis  tinea pedis (athletes foot), tinea capitis (scalp),tinea barbae (under the beard), tinea unguiun (nails)  treatment with antifungal agents Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 32 16 2/4/2016 ABNORMAL CONDITIONS vitiligo: loss of pigment (depigmentation) in areas of skin (milk-white patches) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 33 SKIN NEOPLASMS - BENIGN callus - increased growth of cells in the keratin layer of the epidermis caused by pressure or friction keloid - hypertrophied, thickened scar developing after trauma or surgical incision  excessive collagen formation in the skin during connective tissue repair Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 34 17 2/4/2016 SKIN NEOPLASMS - BENIGN  keratosis: thickened and rough lesion of the epidermis - associated with aging or skin dammage  leukoplakia: white thickened patches of the mucous membrane tissue of the tongue or cheek  nevus: pigmented lesion of the skin (moles)  dysplastic nevi - moles with atypical cells that may progress to skin cancer  verruca: epidermal growth (wart) caused by a virus Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 35 SKIN NEOPLASMS - MALIGNANT basal cell carcinoma - malignant tumor of the basal cell layer of the epidermis  most frequent type of skin cancer  slow growing tumor - chronically sun-exposed skin  almost never metastasizes  treatment - surgical removal Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 36 18 2/4/2016 SKIN NEOPLASMS - MALIGNANT squamous cell carcinoma - malignant tumor of the squamous epithelial cells in the epidermis ● tumors may grow anywhere there is squamous epithelium (mouth, larynx, bladder, esophagus, lungs) ● treatment - surgical removal, cryotherapy, electrodesiccation or radiotherapy Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 37 SKIN NEOPLASMS - MALIGNANT malignant melanoma - cancerous growth composed of melanocytes ● genetic predisposition combined with exposure to ultraviolet light ● usually begins as a mottled, light brown to black macule with irregular borders - lesion may turn shades of red, blue, white and may crust and bleed ● often arise from preexisting moles (dysplastic nevi) and frequently appear on upper back, lower legs, arms and neck ● biopsy required to confirm diagnosis ● melanomas can metastasize to lung, liver, bone and brain ● treatment - excision, regional lymphadenectomy, chemotherapy / immunotherapy or radiotherapy Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 38 19 2/4/2016 SkinNeoplasms — Cancerous (cont’d) the ABCDs of malignant melanoma. A. asymmetry B. border irregular or circumscribed C. color varies from one area to another D. Diameter usually larger than 6mm shades of brown, black (white, red, blue) Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 39 SKIN NEOPLASMS - MALIGNANT Kaposi sarcoma - malignant, vascular, neoplastic growth characterized by cutaneous nodules ● frequently arises on lower extremities ● nodules range in color from deep pink to dark blue or purple ● one form associated with AIDS Copyright © 2011, 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved. 40 20

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