Dermatology Flashcards
chondrodermatitis nodularis helicis
benign painful nodule on top of ear
more common in men
erythema nodosum
inflammation of subcut fat
tender erythematous nodules
normally on shins
resolve in 6 weeks
non scarring
causes-
infections
sarcoid
becets
IBD
PREGNANCY
dermatofibroma/histiocytoma
benign
often precipitated by injury
single firm papule/nodule
skin DIMPLES on pinching
can look similar to BCC
Melanoma major/minor diagnostic criteria
Change in-
size
shape
colour
diameter >6mm
inflammation
oozing
altered sensation
Margin thickness based on Breslow depth for melanoma
0-1mm = 1cm
1-2mm = 1-2cm
2-3mm = 2-3cm
>3mm = 3cm
acne in pregnancy
dont use tetracyclines
use erythromycin instead
also this in children <12
mild-mod acne
12 week course of-
topical adapalene with topical benzoyl peroxide
topical tretinoin with topical clindamycin
topical benzoyl peroxide with topical clindamycin
mod-severe acne
a 12-week course of -
topical adapalene with topical benzoyl peroxide
topical tretinoin with topical clindamycin
topical adapalene with topical benzoyl peroxide + lymecycline or doxycycline
a topical azelaic acid + either oral lymecycline or oral doxycycline
isotretinoin/roaccutain only specialist use
duration of PO ABX treatment acne
6 months max
complication of long term ABX use in acne
gram negative folliculitis
use high dose trimethoprim
acne alternatives to creams/ABX
COCP in women
combine with topical agents
dianette/co-cyprindiol can be used
BUT
increased risk of VTE so second line
only use max 3 months
shingles
give PO antivirals if <72 hrs since onset
- unless <50, no risk factors, mild
famciclovir/valacyclovir first line
aciclovir second line
antivirals reduce incidene post herpetic neuralgia
auspitz sign
picking off white scale in psoriasis exposes red membrane underneath that can bleed
rosacea
nose cheeks forehead
FLUSHING (often with alcohol)
telangiectasias
erythema with papules later
blepharitis
Rx-
flushing/erythema - brimonidine
papules - ivermectin
severe papules add doxy
leukoplakia
white patches in mouth
DIAGNOSIS OF EXCLUSION
must rule out lichen planus and SCC
up to 20% cases can transform to SCC
port wine stain
dark red
do not get better
associated with vascular abnormalities like sturge-weber sydrome
hereditary hemorrhagic telangiectasia
osler-weber-rendu syndrome
autosomal dom
multiple telangiesctasia all over
diagnostic criteria-
1. multiple telangiectasias
2. frequent recurent nosebleeds
3. visceral lesions - AVMs anywhere
4. family history
if has 2 - possible diagnosis
if has 3+ - definite diagnosis
Nikolskys sign
epidermis seperates with mild lateral pressure
seen in TEN
TEN - toxic epidermal necrolysis
scalded appearance
systemically unwell - fevers,tachy
Nikolskys sign positive
normally drug caused-
phenytoin
allopurinol
penicillins
carbamazapine
IVIG first line
pretibial myxodema
symmetrical erythematous lesions over shins
shiny orange peel skin
seen in thyrotoxicosis/graves