7 Dermatology

Learning Objectives Identify the structures of the integumentary system. Describe the process of an allergic reaction. Describe common integumentary diseases and conditions, laboratory and diagnostic procedures, medical and surgical procedures, and drug categories.

Learning Objectives Give the medical meaning of word parts related to the integumentary system. Build integumentary words from word parts and divide and define integumentary words. Spell and pronounce integumentary words.

Learning Objectives Analyze the medical content and meaning of a dermatology report. Dive deeper into dermatology by reviewing the activities at the end of this chapter and online at Medical Terminology Interactive.

Multimedia Directory Slide 28 Anaphylaxis Animation Slide 29 Inflammation Video Slide 38 Burn Animation Slide 42 Decubitus Ulcer Video Slide 61 Skin Cancer Video Slide 68 Acne Video Slide 94 Physician's Assisting Video Slide 95 Physician's Assisting Comparison Video Slide 96 Physician's Assisting and Medical Terminology Video Slide 97 Physician's Assisting and Ethical Situations Video

Dermatology The medical specialty that studies the anatomy and physiology of the integumentary system and uses diagnostic tests, medical and surgical procedures, and drugs to treat integumentary diseases. 6

Figure 7-1 Integumentary system

Anatomy of the Integumentary System Skin consists of two different layers: The epidermis is categorized as epithelial tissue and covers the external surface of the body. The epidermis also includes the mucous membranes that line the walls of internal cavities that connect to the outside of the body. The dermis is categorized as connective tissue. 8

Anatomy of the Integumentary System (cont’d) Epidermis This is the thin, outermost layer of the skin. It contains cells that have no nuclei and are filled with keratin, a hard, fibrous protein. These cells form a protective layer, but they are dead cells, so they are constantly being shed or sloughed off in the process known as exfoliation. 9

Anatomy of the Integumentary System (cont’d) Epidermis (cont’d) The deepest part (basal layer) of the epidermis is composed of living cells that are constantly dividing and being forced to the surface (exfoliation). Does not contain any blood vessels; it receives nutrients and oxygen from the blood vessels in the dermis 10

Anatomy of the Integumentary System (cont’d) Epidermis (cont’d) Contains melanocytes, pigment cells that produce melanin, a dark brown or black pigment that absorbs ultraviolet light from the sun to protect the DNA in skin cells from undergoing genetic mutations 11

Anatomy of the Integumentary System (cont’d) Dermis A thicker layer of skin beneath the epidermis Contains collagen fibers (firm, white protein) and elastin fibers (elastic, yellow protein) Contains arteries, veins, and neurons (nerve cells), as well as hair follicles, sebaceous glands, and sweat glands A dermatome is a specific area on the skin that sends sensory information to the spinal cord. 12

Figure 7-2 Epidermis and dermis 13

Figure 7-3 Dermatomes of the body 14

Anatomy of the Integumentary System (cont’d) Subcutaneous Tissue A loose, connective tissue directly beneath the dermis of the skin Composed of adipose tissue or fat that contains lipocytes (fat-storing cells) Provides a layer of insulation to conserve internal body heat 15

Anatomy of the Integumentary System (cont’d) Subcutaneous Tissue (cont’d) Can be thin or as thick as several inches Subcutaneous layer also acts as a cushion to protect the bones and internal organs 16

Anatomy of the Integumentary System (cont’d) Sebaceous and Sweat Glands Sebaceous glands are a type of exocrine gland in the dermis that secrete sebum through a duct into a hair follicle. Also known as oil glands. Sweat glands are also exocrine glands. Sweat contains water, sodium, and small amounts of body waste (urea, ammonia, creatinine). 17

Anatomy of the Integumentary System (cont’d) Sebaceous and Sweat Glands (cont’d) Sweat glands help to regulate the body temperature. The process of sweating and the sweat itself are both known as perspiration. The sweat glands are also known as the sudoriferous glands. 18

Anatomy of the Integumentary System (cont’d) Hair Covers most of the body Additional facial, axillary, and pubic hairs appear during puberty. Forms in a hair follicle in the dermis 19

Anatomy of the Integumentary System (cont’d) Hair (cont’d) Melanocytes give color to the hair. Hair cells are filled with keratin, which makes the hair shaft strong. Usually, the hair lies flat on the surface of the skin, but when the skin is cold, a tiny erector muscle at the base of the hair follicle contracts and causes the hair to stand up (piloerection). 20

Anatomy of the Integumentary System (cont’d) Nails Cover and protect the distal ends of the fingers and toes Each nail consists of a nail plate, nail bed, cuticle, lunula, and nail root. 21

Figure 7-4 Nail 22

Physiology of an Allergic Reaction An allergy or allergic reaction is a hypersensitivity response to certain types of antigens known as allergens. Allergens include cells from plant and animal sources (foods, pollens, molds, animal dander), as well as dust, chemicals, and drugs. 23

Physiology of an Allergic Reaction (cont’d) The basis of all allergic reactions is the release of histamine from basophils in the blood and mast cells in the connective tissue. A local reaction occurs when an allergen touches the skin or mucous membranes of a hypersensitive individual 24

Physiology of an Allergic Reaction (cont’d) Histamine causes redness (inflammation), swelling (edema), irritation, and itching. 25

Physiology of an Allergic Reaction (cont’d) A systemic reaction occurs when allergens are inhaled or ingested by, or injected into, a hypersensitive person, causing symptoms in several body systems. Histamine constricts the bronchioles, dilates the blood vessels throughout the body, and causes hives on the skin. 26

Physiology of an Allergic Reaction (cont’d) Anaphylaxis is a severe systemic allergic reaction that can be life threatening; it is also known as anaphylactic shock. 27

Anaphylaxis Animation Click on the screenshot to view an animation on the topic of anaphylaxis. Back to Directory 28

Click on the screenshot to view a video on the topic of inflammation. Inflammation Video Click on the screenshot to view a video on the topic of inflammation. Back to Directory 29

Diseases and Conditions General Dermatitis Edema Hemorrhage Lesion 30

Diseases and Conditions General (cont’d) Neoplasm Pruritis Rash Wound Xeroderma 31

Figure 7-5 Edema 32

Figure 7-6 Types of skin lesions. 33

Diseases and Conditions (cont’d) Changes in Skin Color Albinism Cyanosis Erythema Jaundice Necrosis Pallor Vitiligo 34

Figure 7-7 Necrosis and pallo Meyer/Custom Medical Stock Photo, Inc. 35

© Custom Medical Stock Photo, Inc. Figure 7-8 Vitiligo © Custom Medical Stock Photo, Inc. 36

Diseases and Conditions (cont’d) Skin Injuries Abrasion Blister First-degree burn Second-degree burn Third-degree burn Callus Cicatrix 37

Click on the screenshot to view an animation on the topic of burns. Burn Animation Click on the screenshot to view an animation on the topic of burns. Back to Directory 38

Figure 7-9 Second-degree burn of the hand Logical Images, Inc. 39

Custom Medical Stock Photo, Inc. Figure 7-10 Keloid Custom Medical Stock Photo, Inc. 40

Diseases and Conditions (cont’d) Skin Injuries (cont’d) Decubitus ulcer Excoriation Laceration 41

Decubitus Ulcer Video Click on the screenshot to view a video on the topic of decubitus ulcers. Back to Directory 42

Figure 7-11 Decubitus ulcer Custom Medical Stock Photo, Inc. 43

Gill/Custom Medical Stock Photo, Inc. Figure 7-12 Laceration Gill/Custom Medical Stock Photo, Inc. 44

Diseases and Conditions (cont’d) Skin Infections Abscess Cellulitis Herpes simplex virus (HSV) type 1 Herpes simplex virus (HSV) type 2 Herpes whitlow Herpes varicella-zoster Shingles 45

Gill/Custom Medical Stock Photo, Inc. Figure 7-13 Shingles Gill/Custom Medical Stock Photo, Inc. 46

Diseases and Conditions (cont’d) Tinea Tinea capitis Tinea corporis Tinea cruris Tinea pedis Verruca 47

SPL/Photo Researchers, Inc. Figure 7-14 Tinea pedis SPL/Photo Researchers, Inc. 48

Diseases and Conditions (cont’d) Skin Infestations Pediculosis Scabies 49

Diseases and Conditions (cont’d) Allergic Skin Conditions Contact dermatitis Urticaria 50

Figure 7-15 Severe contact dermatitis SPL/Photo Researchers, Inc. 51

Diseases and Conditions (cont’d) Benign Skin Markings and Neoplasms Actinic keratoses Freckle Hemangioma Lipoma Nevus 52

Diseases and Conditions (cont’d) Benign Skin Markings and Neoplasms (cont’d) Papilloma Premalignant skin lesions Senile lentigo Syndactyly Xanthoma 53

Custom Medical Stock Photo, Inc. Figure 7-16 Hemangioma Custom Medical Stock Photo, Inc. 54

Figure 7-17 Nevus 55

Figure 7-18 Senile lentigo. 56

Figure 7-19 Syndactyly 57

Diseases and Conditions (cont’d) Malignant Neoplasms of the Skin Cancer of the skin Basal cell carcinoma Malignant melanoma Squamous cell carcinoma Kaposi’s sarcoma 58

Figure 7-20 Malignant melanoma ISM/Phototake, Inc. 59

Figure 7-21 Kaposi’s sarcoma Zeva Oelbaum/Peter Arnold, Inc. Renumber as Fig. 7-22, and insert new Fig. 7-23. Figure 7-21 Kaposi’s sarcoma Zeva Oelbaum/Peter Arnold, Inc. 60

Click on the screenshot to view a video on the topic of skin cancer. Skin Cancer Video Click on the screenshot to view a video on the topic of skin cancer. Back to Directory 61

Diseases and Conditions (cont’d) Autoimmune Diseases with Skin Symptoms Psoriasis Scleroderma Systemic lupus erythematosus (SLE) 62

NMSB/Custom Medical Stock Photo, Inc. Figure 7-22 Psoriasis NMSB/Custom Medical Stock Photo, Inc. 63

Diseases and Conditions (cont’d) Diseases of the Sebaceous Glands Acne vulgaris Acne rosacea Seborrhea 64

St. Louis; Mosby Year Book Figure 7-23 Acne vulgaris Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 2nd ed., by T.P. Habif, 1990, St. Louis; Mosby Year Book 65

St. Louis; Mosby Year Book Figure 7-24 Acne rosacea Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 2nd ed., by T.P. Habif, 1990, St. Louis; Mosby Year Book 66

Table 7-1 Comparison of Acne Vulgaris and Acne Rosacea 67

Click on the screenshot to view a video on the topic of acne. Acne Video Click on the screenshot to view a video on the topic of acne. Back to Directory 68

Diseases and Conditions (cont’d) Diseases of the Sweat Glands Anhidrosis Diaphoresis 69

Diseases and Conditions (cont’d) Diseases of the Hair Alopecia Folliculitis Hirsutism Pilonidal sinus 70

Diseases and Conditions (cont’d) Diseases of the Nails Clubbing Onychomycosis Paronychia 71

Figure 7-25 Onychomycosis Logical Images, Inc./Custom Medical Stock Photo, Inc. 72

Laboratory and Diagnostic Procedures Allergy skin testing 73

Figure 7-26 Allergy skin testing SIU/Photo Researchers, Inc. 74

Laboratory and Diagnostic Procedures (cont’d) Culture and sensitivity RAST Skin scraping 75

Laboratory and Diagnostic Procedures (cont’d) Tzanck test Wood’s lamp or light 76

Medical and Surgical Procedures Medical Procedures Botox injections Collagen injections Cryosurgery 77

Figure 7-27 Botox injection Suzanne Dunn/The Image Works 78

Medical and Surgical Procedures (cont’d) Medical Procedures (cont’d) Curettage Debridement Electrosurgery Incision and drainage (I&D) 79

Medical and Surgical Procedures (cont’d) Medical Procedures (cont’d) Laser surgery Skin examination 80

Figure 7-28 Skin examination AJ Photo/Photo Researchers, Inc. 81

Medical and Surgical Procedures (cont’d) Medical Procedures (cont’d) Skin resurfacing Chemical peel Dermabrasion Laser skin resurfacing Microdermabrasion Suturing 82

Figure 7-29 Layered closure with sutures 83

Medical and Surgical Procedures (cont’d) Biopsy (Bx) Excisional biopsy Incisional biopsy Needle aspiration Punch biopsy Uses a needle to aspirate the fluid contents in a cyst Shave biopsy Uses a circular metal cutter to remove a plug-shaped core that includes the epidermis, dermis, and subcutaneous tissue 84

Medical and Surgical Procedures (cont’d) Dermatoplasty Liposuction 85

James King-Holmes/D. Mercer/Photo Researchers, Inc. Figure 7-30 Liposuction James King-Holmes/D. Mercer/Photo Researchers, Inc. 86

Medical and Surgical Procedures (cont’d) Mohs’ surgery Rhytidectomy 87

Figure 7-31 Skin grafts Courtesy Martin R. Eichelberger, M.D., Children’s National Medical Center, Washington, DC 88

Medical and Surgical Procedures (cont’d) Skin grafting Autograft Allograft Xenograft Synthetic skin grafts 89

Drug Categories These categories of drugs are used to treat integumentary Diseases and Conditions: Anesthetic drugs Antibiotic drugs Antifungal drugs Antipruritic drugs Antiviral drugs Coal tar drugs 90

Drug Categories (cont’d) These categories of drugs are used to treat integumentary Diseases and Conditions: Corticosteroid drugs Drugs for alopecia Drugs for infestations Photodynamic therapy (PDT) Psoralen drugs Vitamin A-type drugs 91

Figure 7-32 Subcutaneous injection 92

Abbreviations 93

Physician’s Assisting Video Click on the screenshot to view a video on the topic of careers in physician’s assisting. Back to Directory 94

Physician’s Assisting Comparison Video Click on the screenshot to view a video on the topic of comparing physician’s assisting to nurse practitioners. Back to Directory 95

Physician’s Assisting and Medical Terminology Video Click on the screenshot to view a video on the topic of medical terminology in physician’s assisting. Back to Directory 96

Physician’s Assisting and Ethical Situations Video Click on the screenshot to view a video on the topic of ethical situations in physician’s assisting. Back to Directory 97