Basic Derm

Question 1

Macule vs Patch?

Answer 1

Macule = Circumscribed area of change in skin colour, not palpable, below 1cm.
Patch = Over 1cm

Question 2

Papule vs Plaque?

Answer 2

Papule = Circumscribed, elevation of skin ** below 1cm** in diameter
Plaque = Over 1cm

Question 3

Nodule?

Answer 3

Circumscribed visible or palpable lump over 1cm. Depth is important

Question 4

Wheal?

Answer 4

Rounded/flat-topped and pale/red elevated area of cutaneous edema.
Evanescent, due to edema in papillary dermis.

Question 5

Vesicle vs Bullae?

Answer 5

Vesicle = **Over 1cm ** circumscribed, elevated, superficial cavity containing fluid
Bullae = Over 1cm

Question 6

Pustule?

Answer 6

Circumscribed, superficial cavity that contains purulent exudate.
It is turbid

Question 7

Cyst?

Answer 7

Cavity containing liquid/semisolid. Lined by epithelium with fibrous capsule

Question 8

Petechiae vs Purpura?

Answer 8

Petechiae = Smaller bleeding that occurs in skin, non-blanchable.
Purpura = Larger

Question 9

What is erosion?

Answer 9

Defect only in epidermis, heals without scar

Question 10

What is ulcer?

Answer 10

Defect extends to dermis or deeper, heal with scar

Question 11

what is fissure?

Answer 11

Narrow, deep crack

Question 12

What is scale?

Answer 12

Flaking of stratum corneum

Question 13

What is crust?

Answer 13

Dried serous/purulent/blood exudates

Question 14

What is hyperkeratosis?

Answer 14

Thickening of stratum corneum, not flaking off

Question 15

What is Lichenification?

Answer 15

Thickening of skin secondary to chronic scratching, leathery, exaggeration of normal skin lines

Question 16

What is atrophy?

Answer 16

Thinning of skin - epidermis, dermis, both. Skin transparent, telangiectasia, loss of texture, cigarette paper-like wrinkinling, depression, bruising.

Question 17

What is induration?

Answer 17

Dermal thickening causing cutaneous surface to feel thick, firm, tight

Question 18

Only emergency we have to know for derm?

Answer 18

SJS-TEN syndrome. Epidermis died and falls off, revealing dermis layer.
Causes Sepsis, dehydration, overwhelming pain

Question 19

Erysipelas vs Cellulitis?

Answer 19

Cellulitis is very well defined. Erysipelas is a form of cellulitis with marked superficial inflammation, typically affecting the lower limbs and the face.

So Erysipelas less well defined and more superficial

Question 20

Will contact dermatitis get better with steroid cream?

Answer 20

No

Question 21

Triad of Henoch-Schonlein purpura?

Type of IgA vasculitis. Diagnose with skin biopsy

Answer 21

Purpuric rash over extensor surfaces
Abdo pain
Haematuria

Question 22

What is vitiligo?

Answer 22

Irregular, well-demarcated, depigmented macules or matches.
A/w autoimmune thyroid disease and repeated trauma.

Do tzanck test: skin scrap test for cytology

Question 23

Stasis eczema common location?

Answer 23

Usu on gaiter region, due to CVI.

Question 24

What feature suggests Basal Cell Carcinoma?

Answer 24

Pearly, rolled border lesion on nose.

Question 25

Do NSAIDs commonly cause SJS?

Answer 25

YES!

Question 26

Skin prick vs Skin patch test?

Answer 26

Prick is inoculate (intra-dermal)
Patches have wells.
Prick is deeper.

Food allergy = Prick
Contact dermatitis = patch

Question 27

IgG vs IgM vs IgE for food allergy blood test?

Answer 27

Generally all not common.
IgE most common though.
IgM can be done cuz it rises first
IgG cannot be done cuz it doesnt show anything.