Rash

Question 1

rash definition

Answer 1

inflammatory skin eruption

Question 2

steps for constructing a ddx for rash in young adult

Answer 2

1. identify primary lesion
2. determine global reaction pattern
3. distribution of lesions

Question 3

primary lesion definition

Answer 3

initial lesion that has not been altered by trauma or manipulation, and has not regressed

Question 4

secondary lesion definition

Answer 4

develops as the disease evolves or as the patient damages the lesion

Question 5

please take this time to review the types of primary lesions and what defines them

Answer 5

yay! you did it!

Question 6

atrophy

Answer 6

a depression in the skin resulting from thinning of the epidermis, dermis, and/or subcutaneous fat

Question 7

crust

Answer 7

a collection of dried blood, serum, and/or cellular debris

Question 8

erosion

Answer 8

a focal loss of epidermis that does not penetrate below the dermal-epidermal junction and therefore can heal without scarring

Question 9

lichenification

Answer 9

thickening of the epidermis resulting from repeated rubbing, appearing as accentuation of the skin marking

Question 10

scale defintiion

Answer 10

excess dead epidermal cells
may be find, silvery, greasy, dequamative or adherent

Question 11

scar

Answer 11

abnormal formation of connective tissue, implying dermal damage

Question 12

ulcer

Answer 12

focal loss of full-thickness epidermis and partial to full-thickness dermis, which often heals with scarring

Question 13

what are the types of global reaction patterns

Answer 13

papulosquamous eruptions
folliculopapular eruptions
dermal reaction patterns
purpura and petechiae
nonpalpable purpura
blistering disorders

Question 14

papulosquamous eruptions definition

Answer 14

papules and plaques with scale
a type of global reaction pattern

Question 15

folliculopapular eruptions definition

Answer 15

papules forming around the area of skin that has hair distribution
a type of global reaction pattern

Question 16

dermal reaction patterns definition

Answer 16

a type of global reaction pattern
papules, plaques, nodules that have epidermal changes such as scales
smooth primary lesions that can have secondary changes to them

Question 17

purpura and petechiae reaction pattern definition
are these lesions elevated?

Answer 17

discolourations due to blood leaking out of vessels
can be raised when you palpate the skin surface

Question 18

nonpalpable purpura reaction pattern definition
are these lesions elevated?

Answer 18

bruising due to bleeding that is not raised

Question 19

blistering disorders definition

Answer 19

a type of global reaction pattern
fluid filled lesions
includes pus-filled lesions

Question 20

during the dermatological physical exam, what features should you note?

Answer 20

general shape
size
colour
margination
palpation - consistency, deviation of temperature, mobility, tenderness, depth of lesion
number
arrangement - grouped or disseminated
confluence
distribution - isolated, localized vs regional vs generalized, pattern

Question 21

confluence definition

Answer 21

if the multiple lesions flow into each other
if they do not, they are discrete lesions

Question 22

localized vs regional vs generalized definitions

Answer 22

all ways of describing distribution
localized - one spot on the body
regional - one region
generalized - head to toe, all over the body

Question 23

what do ABCDE stand for in evaluating for melanoma and dysplastic nevi

Answer 23

Asymmetry
Irregular Borders - ill defined borders higher risk for melanoma
Variegated Colour - more shades of colour is more concerning
Diameter - >6mm higher risk for malignancy
Evolution/enlargement - quickly changing over time higher risk

Question 24

what types of clinical and laboratory aids are used in dermatological diagnosis

Answer 24

magnification with hand lens
oblique lighting
subdued lighting
wood lamp/UV long wave light/black light
diascopy
dermascopy/epiluminescence microscopy

Question 25

what clinical tests are used in dermatology

Answer 25

patch testing prick testing skin scraping biopsy - punch biopsy and excisional biopsy

Question 26

how is magnification with hand lens used in dermatology

Answer 26

a hand lens or binocular microscope is used to view lesions

Question 27

how is oblique lighting used in dermatology

Answer 27

used to view degrees of elevation or depression in a lesion done in a darkened room

Question 28

how is subdued lighting used in dermatology

Answer 28

used to enhance the contrast between circumscribed hypo- or hyper-pigmented lesions and normal skin involves slightly dimming the lighting

Question 29

how is a wood lamp/UV long wave light/black light used in dermatology what specific conditions can it help identify

Answer 29

can pick up fluorescent pigments and subtle colour differences of melanin pigmentation vitiligo presents as amelanotic tinea capitits and tinea verisolour can sometimes be visualized tinea corporis can NOT be visualized with the wood lamp porphyrias, erythrasama, and pseudomonas bacterial infections can be visualized

Question 30

how is diascopy used in dermatology

Answer 30

by firmly pressing a microscopic slide or glass spatula over a skin lesion, the examiner determines whether the red colour of a macule or papule is due to dilation (erythema) or due to the extravasation of blood (purpura) that does not blanch when you press firmly on the lesion with the glass slide, the skin should blanch if redness is due to capillary dilation because you press all the blood away from the lesion

Question 31

how is dermascopy used in dermatology

Answer 31

a hand lens with a built in lighting and magnification of 10x to 30x is used and allowed for inspection of deeper layers of the epidermis and beyond helps to distinguish between a benign and malignant lesion

Question 32

how is patch testing used in dermatology

Answer 32

confirms a diagnosis of allergic contact sensitization and identify the agent that caused the allergic reaction substances to be tested are placed in shallow cups called Finn chambers and taped onto the skin then left for 24-48 hours contact hypersensitivity will show as a papular vesicular reaction that will develop within 48-72 hours when the test is read

Question 33

how is prick testing used in dermatology

Answer 33

used to determine type 1 allergies a drop of solution containing the allergen is placed on the skin and pierced through with the needle a positive result would be a wheal appearing within 20 minutes caution: the patient must be under constant supervision due to possibility of anaphylaxis

Question 34

how is skin scraping used in dermatology what are the types and what are they used for

Answer 34

- 2 types: dermatophyte/KOH collection and microbiology culture and sensitivity specimen handling biopsy - dermatophyte/KOH collection used for microscopic examination for mycelia of the vesicles or scales or in the hair, so we can view the hyphae and spores - culture and sensitivity - place the antibiotic tablets on the cultured dish and we can see which types of antibiotic would be most effective for eradicating the bacteria

Question 35

what types of biopsy are used in dermatology

Answer 35

punch biopsy excisional biopsy

Question 36

how is punch biopsy used in dermatology

Answer 36

useful in workup of cutaneous neoplasms, pigmented lesions, inflammatory lesions, and chronic skin disorders a 3-4mm punch (small tubular knife) cuts through the dermis, epidermis, and subcutaneous tissue to remove a skin sample

Question 37

how is excisional biopsy used in dermatology

Answer 37

surgical removal of a tumour and some normal tissue around it so you can compare the normal tissue to the lesion to see if the tumor is malignant - this is the "biopsy of choice" because it serves as a treatment for possible malignancy as part of the diagnostic process