Basic Derm Flashcards
Macule vs Patch?
Macule = Circumscribed area of change in skin colour, not palpable, below 1cm.
Patch = Over 1cm
Papule vs Plaque?
Papule = Circumscribed, elevation of skin ** below 1cm** in diameter
Plaque = Over 1cm
Nodule?
Circumscribed visible or palpable lump over 1cm. Depth is important
Wheal?
Rounded/flat-topped and pale/red elevated area of cutaneous edema.
Evanescent, due to edema in papillary dermis.
Vesicle vs Bullae?
Vesicle = **Over 1cm ** circumscribed, elevated, superficial cavity containing fluid
Bullae = Over 1cm
Pustule?
Circumscribed, superficial cavity that contains purulent exudate.
It is turbid
Cyst?
Cavity containing liquid/semisolid. Lined by epithelium with fibrous capsule
Petechiae vs Purpura?
Petechiae = Smaller bleeding that occurs in skin, non-blanchable.
Purpura = Larger
What is erosion?
Defect only in epidermis, heals without scar
What is ulcer?
Defect extends to dermis or deeper, heal with scar
what is fissure?
Narrow, deep crack
What is scale?
Flaking of stratum corneum
What is crust?
Dried serous/purulent/blood exudates
What is hyperkeratosis?
Thickening of stratum corneum, not flaking off
What is Lichenification?
Thickening of skin secondary to chronic scratching, leathery, exaggeration of normal skin lines
What is atrophy?
Thinning of skin - epidermis, dermis, both. Skin transparent, telangiectasia, loss of texture, cigarette paper-like wrinkinling, depression, bruising.
What is induration?
Dermal thickening causing cutaneous surface to feel thick, firm, tight
Only emergency we have to know for derm?
SJS-TEN syndrome. Epidermis died and falls off, revealing dermis layer.
Causes Sepsis, dehydration, overwhelming pain
Erysipelas vs Cellulitis?
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
Will contact dermatitis get better with steroid cream?
No
Triad of Henoch-Schonlein purpura?
Type of IgA vasculitis. Diagnose with skin biopsy
Purpuric rash over extensor surfaces
Abdo pain
Haematuria
What is vitiligo?
Irregular, well-demarcated, depigmented macules or matches.
A/w autoimmune thyroid disease and repeated trauma.
Do tzanck test: skin scrap test for cytology
Stasis eczema common location?
Usu on gaiter region, due to CVI.
What feature suggests Basal Cell Carcinoma?
Pearly, rolled border lesion on nose.
Do NSAIDs commonly cause SJS?
YES!
Skin prick vs Skin patch test?
Prick is inoculate (intra-dermal)
Patches have wells.
Prick is deeper.
Food allergy = Prick
Contact dermatitis = patch
IgG vs IgM vs IgE for food allergy blood test?
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.
