Intro to Derm Flashcards
Terminology
What are primary lesions?
associated with specific causes on previously unaltered skin, occur as initial reactions to the internal or external environment.
Terminology
9 most common primary lesions
- macule
- patch
- papule
- nodule
- plaque
- pustule
- vesicle
- bulla
- wheal
Primary Lesions
define macule
- flat, non-palpable lesion
- less than 1 cm in size
Primary Lesions
define patch
- flat, non-palpable lesion
- greater than 1 cm in size
macule, but bigger!
Primary Lesions
define papule
- raise, palpable, solid lesion
- proliferation of cells in the epidermis and/or dermis
- less than 1 cm in size
Primary Lesions
define nodule
- raised, palpable, solid lesion
- located mid-deep dermis
papule, but deeper!
Primary Lesions
define pustule
- raised lesion
- contains purulent fluid
- less than 1 cm in size
Primary Lesions
define vesicle
- raised, circumscribed lesion
- contains clear to yellow tinged serous fluid
- less than 1 cm in size
Primary Lesions
define bulla
- raised, circumscribed lesion
- contains clear to yellow-tinged serous fluid
- greater than 1 cm in size
vesicle but bigger!
Primary Lesions
define plaque
- raised, palpable flat-topped lesion
- can be formed by confluent papules
- greater than 1 cm in size
Primary Lesions
define wheal
- localized edema
- variety of sizes, typically elevated (papules and plaques)
- transient, < 24 hrs
Secondary Lesions
what are secondary lesions?
lesions that are characteristically brought about by modification of the primary lesion either by the individual with the lesion or through the natural evolution of the lesion in the environment.
Secondary Lesions
7 most common secondary lesions?
- ulceration
- erosion
- excoriation
- fissure
- scales
- crusts
- lichenification
Secondary Lesions
define ulceration
- full-thickness loss of epidermal and dermal skin
Secondary Lesions
define erosion
- loss of superficial epidermis
essentially an unhooded bulla
Secondary Lesions
define excoriation
- superficial abrasion of the skin
- results from scratching, rubbing, digging, and/or squeezing of skin
Secondary Lesions
define fissure
- vertical loss of epidermis extending through epidermal and dermal skin
think deep cracks in skin
Secondary Lesions
define scales
- flakes/plates of compacted, desquamated layers of stratum corneum
peely skin?
Secondary Lesions
define crusts
- collection of cellular debris, dried serum, dried blood on skin’s surface
Secondary Lesions
define lichenification
- thickened, rough skin
- typically due to chronic inflammation or irritation
callus?
Lesions
which lesions are flat?
5 (not all covered earlier)
- macule
- patch
- telangiectasis
- petechia
- purpura
Lesions
which lesions are raised?
6
- papule
- plaque
- nodule
- vesicle/crust/scale
- bulla
- wheal
Lesions
which lesions are deep?
4
- ulcer/erosion
- fissure
- burn injury
- excoriation
Dermatologic Therapies
Most common OTC products?
8 things
- emollients
- anti-seborrheic agents
- anti-fungals
- anti-bacterials
- anti-inflammatories
- anti-itch
- acne/anti-aging
- anti-histamines
Dermatologic Therapies
common prescription products
9
- antibiotics
- corticosteroids
- anti-fungals
- topical calcineurin inhibitors
- retinoids
- oral contraceptives
- spironolactone
- isotretinoin
- biologics
Dermatologic Procedures
Describe woods lamp evaluation
- use of black light to aid in the sx of skin lesions
- most commonly used for evaluation of vitiligo and tinea infections
- hold lamp 10 to 12 cm from skin to dx
rarely used in practice
Dermatologic Procedures
Describe a microscopic evaluation
what preps used when
- potassium hydroxide (KOH): useful for fungal infections
- mineral oil prep: useful for mites (scabies)
Dermatologic Procedures
when to consider for culture?
bacterial vs viral
- bacterial: consider for open wounds, pustules, cystic lesions, rashes
- viral: consider if vesicles are present
Dermatologic Procedures
what is most common injection given?
intralesional corticosteroids
Dermatologic Procedures
which instruments result in the destruction of superficial skin lesions?
2 instruments
- electrodessication
- curettage
Dermatologic Procedures
process for electrodessication & curettage
3 steps
- curette over lesion in all 4 directions
- cauterize skin w/ safety margin
- repeat process for 3 passes
Dermatologic Procedures
what are shave biopsies used for?
superficial skin lesions to confirm diagnosis
Dermatologic Procedures
describe healing process for shave biopsies
- no stitches required
- wound forms a scab that heals in 1-3 wks
Dermatologic Procedures
what does a punch biopsy do that a shave biopsy doesn’t?
give full thickness sample of the skin
Dermatologic Procedures
how is a punch biopsy done?
- disposable, round stainless steel blade is rotated through the skin
- typically 3, 3.5, 4 mm punches are used
Dermatologic Procedures
describe healing process for punch biopsy
- suture may be used to control bleeding but it’s not necessary
- increased likelihood of suture as biopsy diameter increases
Dermatologic Procedures
who performs excisional biopsies?
dermatologists or dermatologic surgeons
Dermatologic Procedures
describe an excisional biopsy
the complete removal of a skin lesion w/ a margin of surrounding tissue taken to minimze recurrence
Dermatologic Procedures
what does MOHS offer?
complete histologic analysis of the tumor margins while permitting maximal conservation of tissue
Dermatologic Procedures
what are the indications for MOHS?
4 things
- location
- aggressive malignancy subtypes
- large tumors/tumors w/ defined borders
- recurrent tumors
Dermatologic Procedures
which locations would be indicative of need for MOHS?
4
- face (nose, eyes, ears, lips)
- scalp
- hands
- groin
Dermatologic Procedures
which malignancy subtypes would be indicative of needing an MOHS?
4
- infiltrative
- sclerosing
- mopheaform
- micronodular
Dermatologic Procedures
When do you use patch testing?
to determine if a pt has a contact sensitivity to a given allergen (testing for type IV hypersensitivity reactions)
Dermatologic Procedures
describe the process of patch testing
what’s applied, what is looked for, when to read?
- small patches of common suspected antigens applied to clean skin
- 48 hrs later, skin is read for evidence of erythema, induration, or blistering
- the test can be re-read over the next 2-5 days as some rxns are delayed
Dermatologic Procedures
describe cryotherapy
the application of liquid nitroden directly to the skin for short durations of time
Dermatologic Procedures
what does cryotherapy result in?
destruction of the superficial layers of the skin
Dermatologic Procedures
what is the result of cryo-destruction from cryo therapy?
blister-like lesion that transforms into an eschar
Dermatologic Procedures
how long until an eschar sheds off the skin?
2-4 wks
Dermatologic Procedures
care before/after treatment?
- no local anesthetic required, generally well tolerated procedure
- minimal wound care
you should never do a superficial shave biopsy if you are considering what as a differential?
melanoma
