Chapter 8: Skin Disorders
Describe the layers of the skin .1
Epidermis: 5 layers that vary in thickness .a
Keratin: waterproofing-
Melanin: skin pigment-determines skin color -
Albinism: lack of melatonin production-
Vitiligo: small area of hypopigmentation-
Melasma: patches of darker skin-
Dermis: Connective tissue containing elastic & collagen fibers .b
Flexibility & strength of skin -
Contains nerves & blood vessels-
Sensory receptors: pressure, touch, pain, heat, cold -
?What are appendages in the skin? What is the function of each .2
Hair follicles: Stratum Basale-hair producing .a
Arrector pili muscle associated with hair follicle -
Sebaceous glands: Produce sebum .b
secretion increases at puberty-influence of sex hormones -
:Sweat glands .c
Eccrine: glands all over body and secrete sweat through pores onto the skin in .i
response to increased heat or emotional stress
Apocrine: sweat glands in axillae, scalp, face, external genitalia and the ducts of .ii
.these glands open into the hair follicles
?What are the 5 functions of the skin .3
(First line of defense (mechanical barrier -
Prevents excessive fluid loss -
Sensory perception-
Synthesizes vitamin D-
(Describe the following skin lesions: (Table 8-1 .2
Vesicle: or blister, thin wall, raised, fluid filled .a
Plaque: slightly elevated, flat, “scale” like lesion .b
Crust: dry rough surface or dried exudate or blood .c
,(Lichenification: thick dry rough surface (leather like .d
Keloid: raised irregular and increasing mass of collagen, resulting from excessive scar .e
tissue formation
Fissure: crack in tissue .f
Ulcer: cavity in tissue .g
Erosion: shallow moist cavity in epidermis .h
Comedome: mass of sebum, keratin & debris blocking the opening of a hair follicle .i
What is pruritus? Chemical irritation caused by insect bites, allergic responses, infestations by .5
.parasites
What can cause it? Release of histamine in hypersensitivity response .a
Why is it harmful to scratch a pruritic area? May break skin increasing risk for infection .b
Describe treatments for pruritus: topical agents (reduce sensation) antihistamines or .c
glucocorticoids. Avoidance of allergens. Antibiotics with infections. Surgery, laser
.(therapy, electrodessication, cryosurgery (Precancerous lesions
?What is the differences between contact dermatitis and allergic dermatitis .6
Contact: exposure to allergen (metals, cosmetics, soaps, chemicals, plants) Occurs on first
exposure. Pruritic rash develops at site few hours later. Direct chemical or mechanical
irritationdoes not involve immune response, is inflammatory b/c of direct exposure (remove
(irritant, reduce inflammation w/ glucocorticoids
.(Allergic: result of type 1 hypersensitivity (ingestion of substances: shellfish, drugs, fruits, nuts
.(Pruritic lesions & hives part of anaphylaxis (check for swelling around mouth & airway
.Administer EpiPen or other first aid
What is atopic dermatitis (Eczema)? Inherited tendency. Chronic inflammation from response .3
.(to allergens (eosinophilia & increased serum IgE levels
.What are clinical manifestations? Children: Rash is erythematous w/ serous exudate .a
Occurs on face, chest & shoulders. Adults: rash is dry, scaly, pruritic on flexor surfaces
How is it treated? Topical glucocorticoids & antihistamines .b
What is psoriasis? Chronic inflammatory skin disorder. Abnormal T cell activation-excessive .4
proliferation of keratinocytes. Increased cellular proliferation
What are the clinical manifestations? Lesions on face, scalp, elbows, knees. Itching or .a
, .(burning sensations (silvery scales
What cells are abnormally activated? T cell .b
What medication are severe cases treated with? Glucocorticoids, tar preparations, .c
antimetabolites
What is scleroderma? Skin disorder may be systemic & affect viscera. Increased collagen .5
deposition
What happens to produce hard, shiny, tight, immovable areas of skin? Inflammation & .a
fibrosis w/ decreased capillary networks
Can this happen elsewhere in the body? May cause renal failure, intestinal obstruction, .b
respiratory failure by distortion of tissues
.What is cellulitis? Bacterial skin infection of the dermis & subcutaneous tissue .6
What organism usually causes it? Staphylococcus aureus & sometimes Streptococcus .a
What are clinical manifestations? Red, swollen & painful areas. Red streaks develop .b
along lymph vessels proximal to infected area
What is a furuncle (boils)? Bacterial Infection .7
What are the clinical manifestations? Large amount of frequent drainage of purulent .a
exudate
Why do we not want to squeeze a boil? Can result in spread of infection to other areas .b
b/c you’re actually pushing the infection further down in the skin rather than pushing it
out
What are carbuncles? Collection of furuncles that form a large infected mass .c
.What is impetigo? Infection, with the appearance of lesions that are common on the face .8
Pruritus is common=scratching & further spread of infection
Is it contagious? VERY in neonates .a
How is it spread? Close physical contact or fomites i.
What is the causative organism? S. aureus .b
What is the treatment? Topical antibiotics (early stages). Systemic administration if .c
extensive
What is acute necrotizing fasciitis? “Fleshing eating” Mixture of aerobic & anaerobic bacteria at .9
site of infection
What is the causative agent? Gram-pos. group A beta-hemolytic Streptococcus .a
What event usually precipitates acute necrotizing fasciitis? Trauma or infection in the .b
skin & subcutaneous tissue of an extremity
Can it be deadly? YES. Bacteria secrete toxins that break down fascia & connective .c
Describe the layers of the skin .1
Epidermis: 5 layers that vary in thickness .a
Keratin: waterproofing-
Melanin: skin pigment-determines skin color -
Albinism: lack of melatonin production-
Vitiligo: small area of hypopigmentation-
Melasma: patches of darker skin-
Dermis: Connective tissue containing elastic & collagen fibers .b
Flexibility & strength of skin -
Contains nerves & blood vessels-
Sensory receptors: pressure, touch, pain, heat, cold -
?What are appendages in the skin? What is the function of each .2
Hair follicles: Stratum Basale-hair producing .a
Arrector pili muscle associated with hair follicle -
Sebaceous glands: Produce sebum .b
secretion increases at puberty-influence of sex hormones -
:Sweat glands .c
Eccrine: glands all over body and secrete sweat through pores onto the skin in .i
response to increased heat or emotional stress
Apocrine: sweat glands in axillae, scalp, face, external genitalia and the ducts of .ii
.these glands open into the hair follicles
?What are the 5 functions of the skin .3
(First line of defense (mechanical barrier -
Prevents excessive fluid loss -
Sensory perception-
Synthesizes vitamin D-
(Describe the following skin lesions: (Table 8-1 .2
Vesicle: or blister, thin wall, raised, fluid filled .a
Plaque: slightly elevated, flat, “scale” like lesion .b
Crust: dry rough surface or dried exudate or blood .c
,(Lichenification: thick dry rough surface (leather like .d
Keloid: raised irregular and increasing mass of collagen, resulting from excessive scar .e
tissue formation
Fissure: crack in tissue .f
Ulcer: cavity in tissue .g
Erosion: shallow moist cavity in epidermis .h
Comedome: mass of sebum, keratin & debris blocking the opening of a hair follicle .i
What is pruritus? Chemical irritation caused by insect bites, allergic responses, infestations by .5
.parasites
What can cause it? Release of histamine in hypersensitivity response .a
Why is it harmful to scratch a pruritic area? May break skin increasing risk for infection .b
Describe treatments for pruritus: topical agents (reduce sensation) antihistamines or .c
glucocorticoids. Avoidance of allergens. Antibiotics with infections. Surgery, laser
.(therapy, electrodessication, cryosurgery (Precancerous lesions
?What is the differences between contact dermatitis and allergic dermatitis .6
Contact: exposure to allergen (metals, cosmetics, soaps, chemicals, plants) Occurs on first
exposure. Pruritic rash develops at site few hours later. Direct chemical or mechanical
irritationdoes not involve immune response, is inflammatory b/c of direct exposure (remove
(irritant, reduce inflammation w/ glucocorticoids
.(Allergic: result of type 1 hypersensitivity (ingestion of substances: shellfish, drugs, fruits, nuts
.(Pruritic lesions & hives part of anaphylaxis (check for swelling around mouth & airway
.Administer EpiPen or other first aid
What is atopic dermatitis (Eczema)? Inherited tendency. Chronic inflammation from response .3
.(to allergens (eosinophilia & increased serum IgE levels
.What are clinical manifestations? Children: Rash is erythematous w/ serous exudate .a
Occurs on face, chest & shoulders. Adults: rash is dry, scaly, pruritic on flexor surfaces
How is it treated? Topical glucocorticoids & antihistamines .b
What is psoriasis? Chronic inflammatory skin disorder. Abnormal T cell activation-excessive .4
proliferation of keratinocytes. Increased cellular proliferation
What are the clinical manifestations? Lesions on face, scalp, elbows, knees. Itching or .a
, .(burning sensations (silvery scales
What cells are abnormally activated? T cell .b
What medication are severe cases treated with? Glucocorticoids, tar preparations, .c
antimetabolites
What is scleroderma? Skin disorder may be systemic & affect viscera. Increased collagen .5
deposition
What happens to produce hard, shiny, tight, immovable areas of skin? Inflammation & .a
fibrosis w/ decreased capillary networks
Can this happen elsewhere in the body? May cause renal failure, intestinal obstruction, .b
respiratory failure by distortion of tissues
.What is cellulitis? Bacterial skin infection of the dermis & subcutaneous tissue .6
What organism usually causes it? Staphylococcus aureus & sometimes Streptococcus .a
What are clinical manifestations? Red, swollen & painful areas. Red streaks develop .b
along lymph vessels proximal to infected area
What is a furuncle (boils)? Bacterial Infection .7
What are the clinical manifestations? Large amount of frequent drainage of purulent .a
exudate
Why do we not want to squeeze a boil? Can result in spread of infection to other areas .b
b/c you’re actually pushing the infection further down in the skin rather than pushing it
out
What are carbuncles? Collection of furuncles that form a large infected mass .c
.What is impetigo? Infection, with the appearance of lesions that are common on the face .8
Pruritus is common=scratching & further spread of infection
Is it contagious? VERY in neonates .a
How is it spread? Close physical contact or fomites i.
What is the causative organism? S. aureus .b
What is the treatment? Topical antibiotics (early stages). Systemic administration if .c
extensive
What is acute necrotizing fasciitis? “Fleshing eating” Mixture of aerobic & anaerobic bacteria at .9
site of infection
What is the causative agent? Gram-pos. group A beta-hemolytic Streptococcus .a
What event usually precipitates acute necrotizing fasciitis? Trauma or infection in the .b
skin & subcutaneous tissue of an extremity
Can it be deadly? YES. Bacteria secrete toxins that break down fascia & connective .c
