Dermatology

Question 1

Cardinal features of skin examination

Answer 1

Distribution of lesions, arrangement/patterns of lesions, morphology of the lesion (shape, size, color, texture, primary vs. secondary)

Question 2

Distribution of lesion includes

Answer 2

Extent- localized, regionalized, generalized, universal
Pattern- symmetry, photodistributed, follicular,
Location- flexural, extensor, palm/soles, scalp, joints, mucous membranes

Question 3

Dermatomal pattern

Answer 3

Distribution of the sensory innervation

Herpes Zoster

Question 4

Grouped arrangement

Answer 4

Clustered within a focal area

Herpes simplex

Question 5

Linear arrangement

Answer 5

Often due to external phenomena

Poison ivy- contact dermatitis

Question 6

Morphology shape- ring like with central clearing

Answer 6

Annular

Ringworm

Question 7

Morphology shape- central depression or dell

Answer 7

Umbilical

Molluscum

Question 8

Oval morphology example

Answer 8

Pityriasis rosea

Question 9

Round or nummular morphology example

Answer 9

Discoid lupus or nummular eczema

Question 10

What determines color of skin morphology?

Answer 10

Endogenous factors- melanin, hemoglobin
Exogenous factors- chemicals (carotene from food and Lycopenic acid from tomatoes) and deposition of material like iron, drugs

Question 11

White morphology

Answer 11

Loss of melanin or hemoglobin
Increase in collagen/scar

Vitiligo

Question 12

Brown morphology

Answer 12

Melanin in epidermis or papillary dermis, iron or increased thickness of skin

Melanocytic nevus

Question 13

blue morphology

Answer 13

Dark substance or cells in dermis or subcutaneous- melanocytes, iron, medicine

Minocycline pigmentation

Question 14

Red morphology

Answer 14

Capillaries- pyogenic granuloma (eroded capillary hemangioma
blood

Question 15

Yellow morphology

Answer 15

Lipid- localized, Xanthelasma

Bilirubin and beta-carotene- generalized

Question 16

Black morphology

Answer 16

Excessive Melanin- dysplastic nevus and melanoma

blood

Question 17

Translucent- clear/shiny morphology

Answer 17

Clear cells in skin- basal cell carcinoma

Fluid collection- eccrine cyst

Question 18

Brown, black and blue morphology (collectively)

Answer 18

Melanin deeper than epidermis- often a sign of malignant melanocytes
Melanoma

Question 19

Black and red morphology

Answer 19

Blood in superficial dermis- purpura

Question 20

Texture morphology- dry, white, adherent

Answer 20

Scaling- cutaneous lupus

Question 21

Examples of primary lesions

Answer 21

Macule/patch
Papule/plaque
Nodule
Vesicle/bulla
Pustule

Question 22

Secondary lesions and differences

Answer 22

Erosion- loss of some epidermis, superficial
Ulcer- loss of complete epidermis, deep loss of skin involving dermis or subcutaneous fat
Fissure- linear split in skin
Eschar- scar/crust on top of lesion
Scratch
Excoriation- erosion or ucler caused by scratching

Question 23

Flat lesions- not palpable, no loss of substance, differs from surrounding skin because of color, smooth or scaling

Answer 23

Macule- small

Patch- greater than 1 cm

Question 24

Raised lesions- palpable due to space occupying substance of cells in skin

Answer 24

Papule: 1-5mm
Plaque: greater than 5mm, SA>height
Nodule: deeper, >5mm, height>SA
Tumor: larger nodule used to describe neoplasm

Question 25

Fluid filled spaces

Answer 25

Vesicles- clear fluid or blood filled, <5mm diameter Bulla- fluid filled, larger than 5mm Pustules- whitish yellow in color, filled with pus (neutrophils or eosinophils) *not automatically infection, caused by hypersensitivity, physical trauma, autoimmune, genetic, etc*

Question 26

Secondary lesion atrophy types

Answer 26

Thinning or wasting of one or all layers of skin Epidermal- topical or injectable steroids Dermal- age Subcutaneous- HIV, injection

Question 27

Clinical description of exam

Answer 27

Distribution, pattern, then morphology Ex) involving the face, torso, extremities Scattered, multiple, discrete and confluent 1-20cm well defined red thick scaling plaques

Question 28

Scraping lab tests

Answer 28

KOH prep for yeast/fungi Cytologic prep (Tzanck smear) in vesicular eruptions to check for infection with virus Mineral oil prep for scabies mite, eggs, feces

Question 29

Other lab tests

Answer 29

Bacterial, viral, fungal cultures Skin biopsy for histology, immunoflourescence or culture Patch test for contact dermatitis