Flashcards in 11. Dermatology Deck (29)
-what if pen allergix
amox/1st gen cephalosporin
Acne tx approach
refractorry: isoreitinoin (get UPreg)
inflamed pustulses: benzyoyl peroxide
comedones: retinoids, topical.
what 2 fungal infxns need oral tx?
-what if don't tx?
-danger of orals?
Hair/Nails needs orals x several months:
-permanent hair loss if don't tx tinea capitis
long term oral can have hepatotox. Therefore, must confirm dx with KOH before starting oral tx
irritant and allergic
irritant: direct toxic chemical effect on skin (occupation related chemical)
allergic: nickel, poison ivy, latex, etc
what is stasis dermatitis
people with leg edema (venous insuff), get leg flaking, erythema, brown discoloration, scaling.
Don't bx, as non-healing ulcer may occur. Venous stasis ulcer may also be present.
pemphigus vs pemphigoid
+ nikolsky's, oral involvement
bx shows tombstones
steroids, MMF, Rituximab, life threatening
- nikolsky's, no oral
bx IF shows Ab to dermal-epidermal jxn
Bullous skin diseases (4 to know):
3. dermatitis herpetiformis
4. porphyria cutanea tarda
porhyria cutanea tarda
-when to suspect
-how to dx
-when you see bullae on skin-exposed surfaces only
-Dark urine. Flouresces 'coral red' under Wood's lamp. (urine uroporphyrins)
tx: avoid sun, Etoh , other triggers.
-what is it
'super-dandruff.' (not seborrheic keratosis)
-cradle cap included
1st step: UV light
topical steroids in flares
-what is this
-what can it be confused with
-herald patch, progressing to salmon-colored lesions.
-can look like rash of syphilis. (syphilis has hands/soles, pityriasis does not)
-steroids, self limiting 6 weeks
-how long after drug exposure
-4-14 days after exposure
Pt with target-shaped lesions on palms, soles.
Think what other than erythema multiforme?
Also, what are causes of erythema multiforme? (3)
1. drug (esp cephalosporins)
-what drugs can cause? (think 4 categories)
SJS vs TEN
-difference, how to know
2 things: body surface area, and Bx
SJS: <10% BSA, Bx shows basal cell degeneration
TEN: >30% BSA, full thickness necrosis
Bx also will find out SSSS
Pt with SJS/TEN: other than getting bx, do what (3)
-remove ALL meds, including steroids (can worsen!).
-Admit to burn unit
SJS/TEN: how many days after drug exposure?
no correlation, could be days or weeks
-what to do if suspect?
Wide excisional bx, punch bx if on face and suspicion low
Seborrheic keratosis vs melanoma
seborrheic keratosis (stuck on age spots, look like ugly moles)
-if present long time, unchanged, it is SK. however, if new or changing, do bx to r/o melanoma.
actinic keratosis: what is dz spectrum?
-do what for actinic keratosis
Bowen's dz (CIS)
pre-SCC, so do Bx. Do local ablation. If CIS/Bowen's resect. Can also do 5-FU, imiquimod
Pt says they had "SCC that went away on its own" on his hand, think what
Keratoacanthoma. looks like SCC but grow and regress spontaneously.
If you see it, do resection like SCC
Pt with patchy depigmentation on skin:
-what dx to think:
-how to dx
1. tinea versicolor.
-KOH prep--sphagethi meatballs
-dx with Woods lamp
-steroids and UV light
-skin findings (3)
1. shagreen patch (raised collagen)
2. sebaceous adenomas (funny looking acne)
3. ash-leaf macules (hypopigmented, use Woods lamp)
salmon colored rash, think what dx
-always check RPR
-tx with topical steroids, 6 weeks self limiting
Patchy alopecia: dx approach?
Make sure exisiting hair same length (otherwise trich). Think tinea capitis--do KOH prep.
If KOH-, think lupus, get ANA.
topical steroids (hydrocortisone)
benadryl is adjunct
-what is time frame after infection?
3-6 weeks after impetigo
1-2 weeks after strep pharyngitis
Hypersensitivity types 1-4?
1. immediate Allergic reaction
2. Ab target antigens on tissue surfaces. eg Graves, Myasthenia gravis, ABO incompat. no rashes.
3. Ag/Ab complexes, depositing on tissues. eg RA, SLE, reactive arthritis
4. delayed, T cells. eg contact dermatitis