Week 2: Ch. 8- Skin Disorders

Question 1

Keratin - ______________ of the skin

Answer 1

Waterproofing

Question 2

Describe melanin

Answer 2

Skin pigment—determines skin color
◦ Production depends on multiple genes and environment

Question 3

Albinism: Lack of

Answer 3

melanin production

Question 4

Vitiligo- Small areas of :

Answer 4

hypopigmentation

Question 5

Melasma- patches of :

Answer 5

darker skin

Question 6

Describe the dermis

Answer 6

◦ Connective tissue
◦ Contains elastic & collagen fibers
◦ Flexibility and strength of the skin
◦ Contains nerves and blood vessels

Includes sensory receptors for:
◦ Pressure
◦ Touch
◦ Pain
◦ Heat
◦ Cold

Question 7

Arrector pili muscle associated with :

Answer 7

hair follicle

Question 8

Sebaceous glands

Answer 8

◦ Produce sebum
◦ Secretion increases at puberty—influence of sex hormones

Question 9

Sweat glands

Answer 9

◦ Eccrine—all over body
◦ Apocrine -Axillae, scalp, face, external genitalia

Question 10

Describe the hypodermis

Answer 10

Beneath dermis
◦ Connective tissue
◦ Fat cells
◦ Macrophages
◦ Fibroblasts
◦ Larger blood vessels
◦ Nerves

Question 11

5 Functions of the Skin

Answer 11

◦ Acts as first line of defense
◦ Prevents excessive fluid loss
◦ Controls body temperature
◦ Active in sensory perception
◦ Synthesizes vitamin D

Question 12

Skin lesions may be caused by:

Answer 12

◦ Systemic disorders - Liver disease
◦ Systemic infections - Chickenpox
◦ Allergies to ingested food or drugs
◦ Localized factors - Include exposure to toxins

Question 13

Pruritus (itching) is associated with:

◦ _________ responses
◦ Chemical irritation caused by _________________
◦ Infestations by ___________________

Answer 13

◦ Allergic responses
◦ Chemical irritation caused by insect bites
◦ Infestations by parasites (e.g., scabies)

Question 14

Diagnostic Tests for Skin Lesions

Answer 14

◦Culture and staining of specimens
-Bacterial infections: microscopic/ direct observations
-Specific procedures for fungal or parasitic infections

◦ Biopsy
-Detection of malignant changes
-Safeguard prior to or following removal of skin lesions

◦ Blood tests - Helpful in diagnosis of conditions caused by allergy or abnormal immune reaction

◦ Skin testing using patch or scratch method

Question 15

General treatment for pruritus

Answer 15

◦ Topical agents to reduce sensation
◦ May be treated by antihistamines or glucocorticoids

Question 16

General treatment for precancerous lesions

Answer 16

◦ Surgery, laser therapy, electrodessication, cryosurgery

Question 17

Urticaria (Hives)

Answer 17

◦ Result of type I hypersensitivity
◦ Ingestion of substances- examples: shellfish, drugs, certain fruits
◦ Lesions are highly pruritic.
◦ Hives are often part of anaphylaxis!
◦ Check for swelling around mouth & check airway.
◦ Administer EpiPen or other first aid as required.

Question 18

Describe Contact Dermatitis

◦ Exposure to_____________________________________________________
◦ Pruritic rash develops at site a few ________ after exposure.

◦ Direct _________________________________________________ irritation
◦ Does not involve ________________ response
◦ Is inflammatory because of direct exposure

—Removal of irritant; Reduction of inflammation with topical glucocorticoids

Answer 18

◦ Exposure to an allergen
[Metals, cosmetics, soaps, chemicals, plants]
◦ Pruritic rash develops at site a few hours after exposure.

◦ Direct chemical or mechanical irritation
◦ Does not involve immune response
◦ Is inflammatory because of direct exposure

—Removal of irritant; Reduction of inflammation with topical glucocorticoids

Question 19

Atopic Dermatitis (Eczema)

Answer 19

◦ Atopic—inherited tendency
◦ Common problem in infancy

◦ Rash is erythematous, with serous exudate.

◦ Commonly occurs on face, chest, and shoulders; rash is dry, scaly, and pruritic, often on flexor surfaces.

◦ Chronic inflammation results from response to allergens.
◦ Eosinophilia and increased serum IgE levels
◦ Potential complication—secondary infections

◦ Treatment: Topical glucocorticoids, antihistamines

Question 20

Psoriasis

Answer 20

◦ Chronic inflammatory skin disorder
◦ Onset usually in the teenage years
◦ Psoriasis results from abnormal T cell activation.
-Excessive proliferation of keratinocytes
-Cellular proliferation is greatly increased.

◦ Lesions found on face, scalp, elbows, knees
◦ Itching or burning sensations

◦ Treatment: Glucocorticoids, tar preparations, antimetabolites

Question 21

Pemphigus

◦ Autoimmune disorder

◦ Autoantibodies disrupt cohesion between _______________________
-Causes ___________________________ to form
-Skin sheds, leaving area painful and open to secondary infection.

◦ May be life-threatening if extensive (e.g., Stevens-Johnson syndrome)

Treatment: Systemic glucocorticoids and immunosuppressants

Answer 21

◦ Autoimmune disorder

◦ Autoantibodies disrupt cohesion between epidermal cells.
-Causes blisters (bullae) to form
-Skin sheds, leaving area painful and open to secondary infection.

◦ May be life-threatening if extensive (e.g., Stevens-Johnson syndrome)

Treatment: Systemic glucocorticoids and immunosuppressants

Question 22

Scleroderma

◦ May be systemic and affect viscera

◦ Primary cause:______________

-Increased _____________ deposition in all cases
-Inflammation & fibrosis w/ decreased capillary networks

◦ Hard, shiny, tight, ____________________ areas of skin
◦ Impaired movement of mouth and eyes
◦ May cause _________ failure, intestinal obstruction, ____________ failure caused by distortion of tissues

Answer 22

◦ May be systemic and affect viscera

◦ Primary cause unknown
-Increased collagen deposition in all cases
-Inflammation & fibrosis w/ decreased capillary networks

◦ Hard, shiny, tight, immovable areas of skin
◦ Impaired movement of mouth and eyes
◦ May cause renal failure, intestinal obstruction, respiratory failure caused by distortion of tissues

Question 23

Skin Infections may be caused by:

Answer 23

bacteria, viruses, fungi, other types of
microbes, parasites

◦ Caused by opportunistic microbes

◦ Minor abrasions or cuts

Question 24

Cellulitis (erysipelas) is a

Answer 24

Bacterial Infection

Question 25

◦ Cellulitis (erysipelas)

Answer 25

◦ Infection of the dermis and subcutaneous tissue ◦ Usually secondary to an injury ◦ May be iatrogenic ◦ Causative organism - Usually Staphylococcus aureus; Sometimes Streptococcus ◦ Frequently in lower trunks and legs ◦ Especially in individuals with restricted circulation in the extremities; also in immunocompromised individuals ◦ Area becomes red, swollen, and painful ◦ Red streaks may develop, running along lymph vessels proximal to infected area

Question 26

Furuncles (boils) are usually caused by:

Answer 26

S. aureus

Question 27

Carbuncles

Answer 27

◦ Collection of furuncles that coalesce to form a large infected mass

Question 28

Impetigo

Answer 28

◦ Common infection in infants & children ◦ May also occur in adults ◦ S. aureus—highly contagious in neonates ◦ Lesions commonly on face ◦ Transmission may occur through close physical contact or through fomites ◦ Pruritus common - Leads to scratching and further spread of infection

Question 29

Impetigo treatment

Answer 29

◦ Topical antibiotics in early stages ◦ Systemic administration if lesions are extensive -Antibiotic-resistant strains of S. aureus are increasing in numbers. -Local outbreaks of infection may result.

Question 30

Acute Necrotizing Fasciitis Cause/Sx

Answer 30

◦ Mixture of aerobic & anaerobic bacteria usually at site of infection ◦ Severe inflammation and tissue necrosis ◦ Usually caused by virulent strain of gram-positive, group A betahemolytic Streptococcus -Bacteria secrete toxins that break down fascia and connective tissue, causing massive tissue destruction. ◦ Delay in treatment—greater tissue loss, potential amputation, chance of mortality ◦ Systemic toxicity develops with fever, tachycardia, hypotension, mental confusion, disorientation, possible organ failure

Question 31

Acute Necrotizing Fasciitis treatment:

Answer 31

◦ Aggressive antimicrobial therapy, fluid replacement ◦ Excision of all infected tissue; amputation

Question 32

Leprosy (Hansen’s Disease) is caused by: affects: treatment:

Answer 32

Mycobacterium leprae ◦ Generally affects skin, mucous membranes, and peripheral nerves ◦ Damage can lead to loss of limbs. ◦ Treatment primarily with antibiotics

Question 33

Herpes Simplex ◦ Herpes simplex type 1 (HSV-1) - cause of ________________________ ◦ Herpes simplex type 2 (HSV-2)—____________ ◦ Both types of HSV cause similar ___________ ◦ Primary infection may be asymptomatic ◦ Virus remains latent in sensory nerve ganglia. ◦ Recurrence may be triggered by: ______________________________________________ ◦ Spread by direct contact with fluid from lesion ◦ Spread of infection to others possible prior to appearance of lesions -Complications: ◦ Spread of virus to eye, Keratitis, Herpetic whitlow, Painful infection of the fingers

Answer 33

◦ Herpes simplex type 1 (HSV-1) - cause of cold sores/fever blisters ◦ Herpes simplex type 2 (HSV-2)—genital herpes ◦ Both types of HSV cause similar effects. ◦ Primary infection may be asymptomatic ◦ Virus remains latent in sensory nerve ganglia. ◦ Recurrence may be triggered by: common cold, sun exposure, stress ◦ Spread by direct contact with fluid from lesion ◦ Spread of infection to others possible prior to appearance of lesions -Complications: ◦ Spread of virus to eye, Keratitis, Herpetic whitlow, Painful infection of the fingers

Question 34

Verrucae (Warts)

Answer 34

◦ Human papillomavirus (HPV) types 1 - 4 ◦ Frequently develop in children and young adults ◦ Plantar warts are common. ◦ Spreads by viral shedding of the skin surface ◦ May resolve spontaneously with time ◦ Genital warts (HPV types 6 & 11)

Question 35

◦ Candida infection is associated with:

Answer 35

diabetes.

Question 36

Most fungal infections are:

Answer 36

superficial

Question 37

Tinea capitis

Answer 37

◦ Infection of the scalp ◦ Common in school-age children ◦ Erythema may be apparent. ◦ Oral antifungal medication

Question 38

Tinea corporis

Answer 38

◦ Infection of the body, particularly of nonhairy parts ◦ Round lesion with clear center (ringworm) ◦ Pruritus may be present. ◦ Topical antifungal medication

Question 39

Tinea pedis

Answer 39

◦ Athlete’s foot—involves feet, particularly toes ◦ Associated with swimming pools & gyms ◦ May be part of normal flora that becomes opportunistic ◦ Secondary bacterial infection may occur ◦ Topical antifungal medication

Question 40

Tinea unguium

Answer 40

◦ Infection of the nails, particularly toenails ◦ Nails turn white, then brown. ◦ Nail thickens and cracks. ◦ Infection tends to spread to other nails.

Question 41

Scabies

Answer 41

◦ Invasion by mite Sarcoptes scabiei -Female burrows into epidermis; lays eggs over several weeks -Male dies after fertilizing; Female dies after laying the eggs. ◦ Larvae migrate to skin surface > Burrow into skin in search of nutrients - Intensively pruritic! ◦ Larvae mature and cycle is repeated ◦ Burrows appear on skin as tiny, light brown lines.

Question 42

Pediculosis (lice)

Answer 42

◦ Pediculus humanus corporis—body louse ◦ Pediculus humanus capitis—head louse ◦ Pediculus humanus pubis—pubic louse ◦ Female lice lay eggs on hair shafts. ◦ After hatching, louse bites human host, sucking blood for production of ova ◦ Excoriations result from scratching

Question 43

Keratoses

Answer 43

◦ Benign lesions usually associated with aging or skin damage. ◦ Seborrheic keratoses- Proliferation of basal cells; Lead to oval elevation; May be smooth or rough ◦ Actinic keratoses- On skin exposed to ultraviolet radiation; Commonly in fair-skinned persons; Lesion appears as pigmented, scaly patch

Question 44

Guidelines to Reduce Risk of Skin Cancers

Answer 44

◦ Reducing sun exposure ◦ Covering up with clothing ◦ Remaining in shade ◦ Wearing brimmed hats to protect face & neck ◦ Applying sunscreen/sunblock

Question 45

Squamous Cell Carcinoma

Answer 45

◦ Painless, malignant tumor of the epidermis ◦ Lesions most commonly found on exposed areas of the skin but also in oral cavity- Face, neck, Base of tongue ◦ Excellent prognosis when lesion is removed within reasonable time ◦ Invasive type arises from premalignant condition.

Question 46

Malignant Melanoma

Answer 46

◦ Highly metastatic form of skin cancer ◦ Develops in melanocytes from a nevus (mole) ◦ Often appear as multicolored lesion with irregular border -Grow quickly, Change in shape, color, size, texture; May bleed ◦ Treatment: surgical removal and radiation plus chemotherapy

Question 47

The ABCD of Melanoma

Answer 47

◦ Melanoma is suspected in any nevus that shows: ◦ Change in appearance ◦ Change in border ◦ Change in color ◦ Increase in diameter

Question 48

Kaposi’s Sarcoma

Answer 48

◦ Occurs in those with AIDS and other immunodeficiencies ◦ May affect viscera & skin ◦ Malignant cells arise from endothelium in small blood vessels -Purplish macules; Nonpruritic, nonpainful ◦ In immunocompromised, lesions develop rapidly over upper body. Treatment: Combo of radiation, chemotherapy, surgery, biological therapy

Question 49

Plantar warts are caused by:

Answer 49

human papillomavirus.

Question 50

Which of the following statements regarding acute necrotizing fasciitis is TRUE? It is usually caused by S. aureus. Infection is localized in a small area of the epidermis. Spontaneous recovery usually occurs in 48 hours. Infection rapidly causes extensive tissue necrosis and toxic shock.

Answer 50

Infection rapidly causes extensive tissue necrosis and toxic shock.

Question 51

Which type of microbe causes Tinea infections?

Answer 51

Fungus

Question 52

What causes the pruritus associated with scabies?

Answer 52

Mites burrowing into the epidermis and reaction to their feces

Question 53

How can pediculosis be diagnosed?

Answer 53

The presence of nits at the base of hair shafts [lice]

Question 54

What is the major predisposing factor to squamous cell carcinoma?

Answer 54

Exposure to ultraviolet light

Question 55

All of the following statements apply to malignant melanoma EXCEPT: The malignant cell is a melanocyte. The neoplasm grows rapidly and metastasizes early. The lesion is usually dark or multicolored with an irregular border. They present as non-pruritic purplish macules.

Answer 55

They present as non-pruritic purplish macules.

Question 56

What factor has contributed to the increased incidence of Kaposi’s sarcoma?

Answer 56

immunosuppressed individuals

Question 57

The cause of contact dermatitis can often be identified by:

Answer 57

noting the location and size of the lesion.

Question 58

Scabies—usually on the:

Answer 58

fingers, wrists, waist

Question 59

Leprosy (Hansen’s disease) is caused by:

Answer 59

a bacterium.

Question 60

Impetigo is highly:

Answer 60

contagious