Lecture 1: Intro Flashcards Preview

Gen Med: Dermatology > Lecture 1: Intro > Flashcards

Flashcards in Lecture 1: Intro Deck (77):
1

What are the layers of the skin?

1. Epidermis
2. Basement membrane
3. Dermis
4. Subcutaneous layer

2

What are the functions of the skin?

1. Protection from UV through melanin
2. Resist mechanical shock
3. Thermoregulation
4. Mediates sensation
5. Protects from environment
6. Affects social/sexual communication
7. immune barrier to pathogenic org.
8. assists in Vitamin D synthesis
9. Assists in toxin excretion
10. Regulates body fluid loss

3

How much vitamin D synthesis is performed in the skin?

10-15%

4

What are the categories/terms used to describe skin lesions?

1. Size
2. Color and descriptive terms
3. Primary skin lesions
4. Secondary skin lesions
5. Special skin lesion
6. Arrangement
7. Distribution

5

What are primary skin lesions?

nitial lesions, not altered by trauma, manipulation or natural regression over time

6

What are secondary skin lesions?

How the lesions looks over time or after manipulation (ie. scratching, picking, leaking, bursting)

7

Define depigmented skin

1. Absent of melanocytes, no melanin therefore no color

8

How is skin typed?

1. Albino
2. Caucasian
3. Mediterranean
4. Hispanic
5.
6. Darkly pigmented: african american

9

What disease causes depigmentation of the skin?

Vitilago

10

Define hypopigmentation

1. Normal number of melanocytes, but Decreased production of Melanin
2. Lighter than skin color

11

Define Hyperpigmented skin

1. Normal # of Melanocytes but
Increased production of Melanin
2. Darker than skin color

12

What causes hypopigmented skin?

Psoriasis?

13

Define erythematous skin

redness of skin

14

Define atrophic skin, in the epidermal and dermal layers

1. thinning of skin
2. Epidermal - “cigarette paper”wrinkling
3. Dermal/Subcutis – Depression in skin

15

Define lichenified skin lesions

1. Focal area of thick skin
2. Produced by chronic manipulation
3. Accentuated skin lines – “washboard”

16

Define verrucous skin lesions

Hyperkeratotic or Wart Like

17

Define Umbilicated skin lesions

Central “belly button” like depression

18

What terms are used to describe primary skin lesions?

MACULE - PATCH
PAPULE - PLAQUE
NODULE
PUSTULE - CYST
VESICLE - BULLAE
WHEAL

19

Define macule skin lesions

1. Small
2. Flat circumscribed skin discolorations
3. Lacking surface elevation or depression

20

Define patch skin lesions

1. Large
2. Flat circumscribed skin discolorations
3. Lacking surface elevation or depression
4. A very large macule

21

Define papule skin lesions

1. Elevated solid lesion
2. <5mm

22

Define plaque skin lesions

1. Elevated solid confluence of papules
2. >5mm
3. Lacking a deep component

23

Define nodule skin lesions

1. Elevated solid lesion
2. >5mm
3. A larger and deeper paple

24

Define pustule skin lesions

1. Papule that contains
Purulent material
2. <5mm
3. Not necessarily infected

25

Define cystic skin lesions

Nodule that contains
fluid or semisolid material

26

Define vesicular skin lesions

1. Papule that contains clear fluid
2. <5mm
3. called hemorrhagic vesicle if filled with blood

27

Define bullae skin lesions

1. Localized fluid collection
2. A large vesicle
3. >5mm
4. called hemorrhagic bullae if filled with blood

28

Define wheal skin lesions

1. Firm edematous plaque
That is evanescent (coming and going) and pruritic
2. Hives

29

What terms are used to describe secondary skin lesions

SCALE - CRUST
EROSION - ULCER
FISSURE - EXCORIATION
SCAR

30

Define scale skin lesions

Thickened Stratum Corneum
secondary to keratinocyte hyperproliferation

31

Define crust skin lesions

Collection of cellular debris
Dried serum, blood = Scab

32

Define erosion skin lesions

Superficial focal loss of epidermis
Heals without scarring

33

Define ulcer skin lesions

Full thickness focal loss of epidermis and dermis
Heals with scarring

34

Define fissure skin lesions

Verticle loss of epidermis and dermis Sharply defined walls
“Cracking” skin

35

Define excoriation skin lesions

Linear erosion induced by scratching

36

Define scarring

A collection of new connective tissue
Implies dermoepidermal damage
May be hypertrophic (too much collagen-raised scar) or atrophic (too little collagen-depressed scar)

37

What terms are used to describe special lesions?

TELANGIECTASIAS
PETECHIAE - PURPURA
COMEDONES
TARGET LESIONS
STRIAE
BURROW

38

Define TELANGIECTASIAS
skin lesions

Small dilated superficial blood vessels
Blanchable

39

Define petechiae
skin lesions

Extravasation of RBC’s into Dermis
Non-Blanchable
<5mm

40

Define purpura
skin lesions

Extravasation of RBC’s into Dermis
Non-Blanchable
>5mm
Can turn into ecchymosis

41

Define comedomes
skin lesions, open vs. closed

Folliculocentric collection of sebum and keratin
Closed Comedone = “whitehead”
Open Comedone = blackhead, due to oxidation bc exposed to air

42

Define target
skin lesions

Consist of three zones
Center bulls eye
Second pale zone
Third rim of erythema

43

Define striae
skin lesions

Irreversible atrophic violaceous linear damage to skin "stretch marks"
Secondary to Topical Steroids overuse
Cushings Syndrome or Excessive rapid growth

44

Define burrows
skin lesions

Elevated channel in the superficial epidermis
Produced by parasites (Scabies, Hookworm)

45

What terms are used to describe the characteristic arrangements of skin lesions? When are they used?

ANNULAR
GYRATE
DERMATOMAL
LINEAR
GROUPED
KOEBNERIZATION
Remember to use them in the “description template” just after the type of skin lesions

46

Define annular
skin lesions

Ring shaped

47

Define gyrate
skin lesions

From Latin – “to turn in a circle”

48

Define dermatomal
skin lesions

Follows neurocutaneous dermatomes

49

Define linear
skin lesions

Skin lesions in a linear configuration

50

Define grouped
skin lesions

Skin lesions in a grouped configuration

51

Define koebnerization
skin lesions

Traumatized skin produces lesions
Koebner Phenomenon occurs with only certain skin diseases (LP, LN, PSOR)

52

What terms are used to describe specific patterns of distribution?

Bilateral - Unilateral
Flexural - Extensor
Malar

53

What diagnostic techniques in dermatology?

Skin Scrapings
Woods Lamp
Cultures
Patch Test
Skin Biopsies

54

What are the types of skin scrapings?

KOH, Tzanck Smears, and Scabies Smears

55

What are the different solvents used in skin scrapings?

1. KOH Stain = Potassium Hydroxide
2. Tzanck Smear = Giemsa, Wrights, or Sedi stains
3. Scabies Smear = Mineral Oil, KOH, Saline

56

What is the most sensitive in office skin scraping technique?

KOH

57

What is KOH skin scraping used for?

Can aid in identifying
Tinea/Candida infections

58

HOW IS A KOH SKIN SCRAPING DONE CORRECTLY WHEN LOOKING FOR TINEA?

Sample correct area
Tops of vesicles
Leading edge of Annular Lesions
Deep Scrapings of Nails for subungual debris

59

What is the Tzanck smear used for? What are the limitations?

1. Standard microscopic test for rapid Dx of Herpes infection
2. cannot distinguish between the types of herpes (HSV ½ or VZV)

60

What is the desired target of Tzanck smear?

Looking for Atypical Keratinocytes with Lg Nuclei
Multinucleated Giant Cells

61

HOW IS A TZANCK SMEAR DONE?

1. Sample correct area
A. Scrape base of “vesicle/bulla”
B. Sample only a “Fresh” lesion
2. Follow these steps
A. Use #15 blade to correct area and transfer to slide
B. Stain with either Giemsa, Wrights, or Sedi stain
C. Coverslip
D. Look for “Multinucleated Giant Cells”

62

What is the etiology of scabies?

Caused by a mite Sarcoptes Scabiei var. hominis

63

How is scabies diagnosed?

Diagnosis is made by identifying the female mite, her eggs, or fecal material under the microscope

64

HOW IS A SCABIES SMEAR DONE?

1. Sample correct area
A. Scrape “Burrows”, vesicles, or papules
B. Have patient point with index finger to itchy area
C. Important to sample - finger webs, flexural wrists, genitalia
2. Follow these steps
A. Apply Mineral oil to sample area
B. Use #15 blade and vigorously scrape area
(ok to scrape til small amount of bleeding)
C. Coverslip
D. Look for Female Mite, Eggs, or Fecal Material
E. Mites also seen using KOH or Saline wet mount Preps

65

What is the Wood's lamp exam?

Fluorescing affected areas with invisible
“Black Light” (long wave UV radiation)

66

What does the Wood's lamp exam aid in identification of? What are the diagnostic colors of certain pathogens?

1. Tinea Capitis infections (non T. Tonsurans) = yellow-green
2. Tinea Versicolor – dull yellow
3. Erythrasma – coral red
4. Pseudomonal – green
5. Vitiligo – accentuates epidermal pigment if present

67

What are the best methods for bacterial culture swab?

1. Best yield when superficial infection
2. Swab vigorously area of most inflammation
3. Results in about 1 wk

68

What are the best methods for viral culture swab?

Keep Refrigerated
Best to sample base of fresh vesicle or bullae
Results in about 1 wk

69

What are the best methods for fungal culture swab?

1. DTM – Turns Red if Dermatophyte is present (no ID)Results over several wks
2. Sabouraud’s Dextrose Agar – Used to ID type of Dermatophyte Results over a month

70

What is the test of choice to differentiate between contact allergic vs. irritant dermatitis?

Patch test

71

Define allergic contact dermatitis

1. Immunologically mediated
2. An acquired sensitivity affecting certain individuals

72

Define irritant contact dermatitis

1. Is not immunologically mediated
2. Due more to chemical damage to skin

73

When are skin biopsies the best diagnostic technique?

For cutaneous neoplasms that cannont be Dx clinically

74

When are skin biopsies a helpful diagnostic technique?

In inflammatory skin disorders of uncertain etiology

75

What are skin biopsy samples used for?

H&E histology examination
Specialized studies such as Immunofluorescence, electron microscopy, cultures, special stains, PCR studies, etc.

76

What are the different types of skin biopsies? What are the most common types?

CURETTE BIOPSY
SCISSOR BIOPSY
SHAVE BIOPSY
PUNCH BIOPSY
INCISIONAL BIOPSY
EXCISIONAL BIOPSY
2. Shave and punch

77

What are the in office treatment procedures for derm?

Lasers, Light Therapy, Phototherapy, and PDT
Resurfacing Procedures
Injectables