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Flashcards in Dermatology Deck (45):
1

Layers of epidermis

From surface to base:
-stratum corneum (keratin-containing)
-stratum lucidum
-stratum granulosum
-stratum spinosum (desmosome containing)
-stratum basale (stem cell site)

2

Zonula occludens

Tight junctions of skin. Prevent paracellular movement of solutes. Made of claudins and occludens. Most superficial connection of skin cells.

3

Zonula adherens

Adherens junctions of skin. Cadherins connect actin cytoskeletons of adjacent cells. Deep to tight junction; superficial to desmosomes.

4

Macula adherens

Desmosomes. Provide support by keratin interactions. Autoantibodies develop against them in pemphigus vulgaris.

5

Gap junctions

Deepest cell-cell junction in skin. Connexons allow for electric and chemical communication between cells.

6

Hemidesmosome

Connects keratin in basal cells to underyling basement membrane. Autoantibodies against them in bullous pemphigoid.

7

Spongiosis

epidermal accumulation of edematous fluid in intercellular spaces

8

Acantholysis

Separation of epidermal cells

9

Acanthosis

Epidermal hyperplasia

10

Albinism

Normal melanocyte number; decreased melanin production due to decreased tyrosinase activity or defective tyrosine transport. Also can be caused by failed nueral crest migration during development

11

Melasma

Hyperpigmentation associated iwth pregnancy or OCP use

12

Vitiligo

Irregular areas of depigmentation due to autoimmune destruction of melanocytes

13

Atopic dermatitis

Same thing as eczema. Prurutic eruption on skin flexures. Starts on face in infancy; appears in antecubital fossae later

14

Allergic contact dermatitis

Type IV hypersensitivity

15

Melanocytic nevus

Regular mole. Intradermal are papular; junctional are flat

16

Psoriasis

Papules and plaques with silvery scale. Acanthosis (epidermal hyperplasia) wither parakeratotic scaling (nuclei still in stratum corneum). Increased stratum spinosum; decreased stratum granulosum.

17

Auspitz sign

Pinpoint bleeding spots from exposure of dermal papillae when scales scraped off seen in psoriasis.

18

Rosacea

Inflammatory skin disorder with erythematous papules and pustules.

19

Seborrheic keratosis

Flat, greasy, pigmented squamous epithelial proliferation. Look stuck on. Occur on head, trunk, extremities.

20

Leser-Trelat sign

sudden apperance of multiple seborrheic keratoses; suggests underlying malignancy

21

Impetigo

Superficial skin infection caused by S aureus or S pyogenes. Honey colored crusting. S aureus can cause bullae as well.

22

Cellulitis

Infection of dermis and SC tissue. Usually S pyogenes or S aureus.

23

Erysipelas

Inferction of upper dermis and superficial lymphatics. Usually strep pyogenes. Well-defined demarcation between infected and normal skin

24

Abscess

Pus walled off within skin. Almost alwyas S aureus

25

Necrotizing fasciitis

Deep tissue injury from anaerobes or S pyogenes. Causes crepitus. Bullae and purplish color to skin

26

Staph scalded skin syndrome

Exotoxin destroys keratinocyte attachments in stratum granulosum. Fever, rash, skin sloughing

27

Molloscum contagiosum

Papules caused by poxvirus (dsDNA, replicates in cytoplasm)

28

Hairy leukoplakia

Irregular, white, painless plaques on tongue that can't be scraped off. Caused by EBV in immunocompromised patients.

29

Pemphigus vulgaris

Potentially fatal. IgG against desmoglein in desmosomes. Flaccid intraepidermal bullae. Oral mucosa involved. Separation of epidermis on manual stroking of skin. Net-like apattern on IF.

30

Bullous pemphigoid

IgG against hemidesmosomes. Tense blisters containing eosinophils on skin. Oral mucosa spared. Linear pattern on IF.

31

Dermatitis herpetiformis

Pruritic papules, vesicles, bullae due to IgA deposits at tips of dermal papillae. Associatd with celica

32

Erythema multiforme

Associated with infections, drugs, cancer, and autoimmune disease. Multiple types of lesions

33

Stevens Johnson syndrome

Fever, bullae and necrosis, skin sloughing. High mortality rate. Adverse drug reaction

34

Acanthosis nigricans

Epidermal hyperplasia causing hyperpigmented thickening of skin in axilla or neck. Associated with high insulin and visceral malignancies

35

Actinic keratosis

Premalignant lesions caused by sun exposure. Small, rough, red or brown papules or plaques.

36

Erythema nodosum

Painful inflammatory lesions of subcutaneous fat on anterior shins

37

Lichen planus

Associated with hep C. Pruritic purple polygonal palmar papules and plaques. Wickham strae if mucosal involvement- reticular white lines.

38

Pityriasis rosea

Patch followed by other scaly erythematous plaques in christmas ree distriution. Self-resolves in 6-8 weeks

39

Basal cell carcinoma

Pink pearly nodules. Often with telangiectasias, rolled borders, central crusting or ulceration. Palisading nuclei

40

Squamous cell carcinoma

Associated with immunosuppression. Face, lower lip, ears, and hands are most common spot. Ulcerative red lesions with frequent scale. Keratin pearls on histology. Actinic keratosis is precursor lesion.

41

Melanoma

S-100 tumor marker. Depth of tumor correlates with risk of metastasis.

Types: superficial spreading, nodular, lentigo maligna, acral lentiginous

BRAF mutations common

42

Types of bruises

Petechiae: pinpoint to pinhead (less than 5mm) bruises

Purpora: 5mm to 1 cm

Ecchymoses: over 1cm

43

TGF beta

Stimulates connective tissue synthesis and remodeling of ECM. Persistently elevated in formation of keloid scars

44

Ehlers-Danlos syndrome

Can be caused by procollagen peptidase deficiency, reuslting in impaired cleavage of terminal propeptides in ECM.

45

Response to foreign body in a wound

Granulation tissue