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Flashcards in Skin Deck (31)
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What are the main layers of the skin?

epidermis = keratinocytes and melanocytes

dermis = connective tissue (BV, nerves hair follicles)

subcutis = fat tissue


Give clinical examples of a macule, patch, papule, vesicle, pustule, plaque, ulcer, and nodule.

macule = freckle

patch = measles

papule = eczema

vesicle = herpes

pustule = impetigo

plaque = psoriasis?

ulcer = chancre

nodule = ?


What is icthyosis?

A congenital thickening of the skin, forming numerous large scales (squames)


What is albinism?

Generalized hypopigmentation caused by inborn error of metabolism. Individual lacks enzyme essential for the synthesis of melanin (from aa tyrosine and phenylalanine).


What is epidermolysis bullosa?

Term used for several congenital skin disorders, all characterized by the formation of blisters on rubbing of the skin or minor trauma (usually on palms and soles)


Explain the effects of mechanical trauma on the skin and subQ tissues. 

Blunt trauma: usually causes contusion, bleeding into skin and soft tissues.

Laceration: disruption of skin and underlying soft tissue.


What are the differences between first-degree, second-degree, and third degree burns?

1st: erythema and swelling, spotty, single cell necrosis and edema.

2nd: epidermal blisters (spares follicles)

3rd: massive necrosis of entire epidermis and dermis


Compare immersion foot and frostbite.

Immersion foot = exposure to nonfreezing cold and moist environment. small blood vesses, stunned by cold become permanently dilated and unable to regulate local blood flow. venous stagnation >> necrosis >> blisters and ulcers


frostbite = exposure to subfreezing temperature. blotchy, red and swollen with reheating >> gangrene


Describe an "electric mark" on the skin.

Passage of electricity generates hear, which burns the tissues >> linear marks


Compare the effects of acute and chronic sun exposure.

acute = hyperemia, 1st or 2nd degree thermal injury

chronic = skin becomes more birttle, less elastic, develops wrinkles, resist injury less efficiently, skin cancer


Describe and explain the pathogenesis of impetigo, folliculitis, furuncle, and carbuncle.

Impetigo: highly contagious, heals without scars, strep or staph aureusI, honey colored scab, superficial

Folliculitis: limited to hair follicles

Furuncle: bacteria invades hair shaft and extends into perifollicular tissue

Carbuncle: enlarges to include several hair follicles


Compare superficial dermatophytosis with deep fungal infections.

Superficial dermatophytosis >> live in surface area, causing no inflammation of underlying skin

Deep fungal infections >> cause large destructive lesions and tumor like lesions


List viruses that infect skin.

measles, chickenpos, herpes zoster, herpes labialis, HPV


Describe insect bites.

itchy, maculopapular skin lesion with a red dot in the center. 


What is scabies?

Caused by a mite. Creates burrows in the superfiical layers of the epidermis. Maculopapular eruptions evolve in reponse ot the bite, feces, or ova


Describe the pathology of acne and explain its pathogenesis.

May have hereditary, hormonal, and bacterial factors.

Hormones: promote hyperkeratosis, blocking discharge of sebum, also sitmulate sebaceous glands

Retained sebum is colonized by bacteria. 


What is eczema?

Chronic dermatitis, edema, hyperkeratosis

exogenous = environmental irritants, contact dermatitis

endogenous = autoimmune disorders


What is seborrheic dermatitis?

Chronic disease with reddening, scaling, itching

Especially nasolabial folds, eyebrows, upper chest


Describe the pathologic and clinical features of psoriasis.

Generalized papulosquamous disease

presents with slighly elevated papules and patches >> silvery scales

often on extensor surface of extremities, scalp and nails



Classify skin neoplasms.

Tumors of 

- epithelial cells

- pigmentary cells

- dermal connective tissue

- bloodborne immigrant cells


What is seborrheic keratosis?

most common benign epidermal tumor

brownish, solitary/multiple, mulberry shaped, wartlike, exophytic, flat-topped lesion with corrugated furrowed surface

papillae lined with basaloid cells

not premalignant


Compare basal cell and squamous cell carcinoma.

Basal cell: most common malignant epithelial tumor, sun-exposed skin, islands and strands of invasive neoplastic cells resembling those in the basal layer

slightly elevated nodule with a central depression

Squamous cell: malignant, sun-exposed skin, typically locally invasive

plaque, small persistent ulcer


What is actinic keratosis?

1/2 squamous cell carcinoma

similar to cancer, but no invasion of underlying tissue typically >> carcinoma in situ


What are the most important telltale signs of skin cancer?

- persistent, nonhealing ulcer, containing friable, bleeding tissue

- ulcer or nodule of irregular shape and indistince margins

- ulcer surrounded by atrophic and keratotic skin typical of sunlight injury


Compare freckle with lentigo and nevus.

freckle = patch of hyper-reactive melanocytes

lentigo = sharply demarcted macule with increased melanocytes

nevus = accumulation of melanocytes


Classify malignant melanomas.

lentigo maligna flat, macular lesion, originates in a preexisting freckle

superficial spreading of melanoma 70%, irregularly pigmented macules with irregular edges, pruritic, legs (w) back (m)

nodular melanoma vertical growth, infiltrating variant

acral-lentiginous melanoma palms, plantar surfaces, asians/blacks


List the ABCD of diagnosis of malignant melanoma.

A = assymmetry of lesion

B = irregular borders

C = marked variation of color 

D = > 6mm usually 


What is Kaposi's sarcoma, and how is it related to the AIDS epidemic?

Composed of BV and perivascular connective tissue

AIDs facilitates the prolferation of blood vessls, herpes virus 8?


Compare mycosis fungoides and urticaria pigmentosa.

MF: T cell lymphoma

skin macules/papules > nodules > ulcerating masses

UP: dermal infiltrates of mast cells

brownish-red macules, elevated papules > flare with trouching or stroking


Describe the main features of nail infections. 

koilonychia = spoon-shaped nails

clubbing = chronic pulmonary disease

paronychia = bacterial infection of cuticle

onchomycoses = fungal infection