random factoids Flashcards
bullous pemphogoid has a problem with…
hemidesmosomes
pemphigus vulgaris has a problem with …
desmoglein-3
drop like lesions
guttate psoriasis
derm feature of endocarditis
finger clubbing
asteatotic eczema patient presentation
elderly patietns in the winter months with dry legs
removal of melanoma rules
first removed with 2mm excisional biopsy then breslows value is added
onion skin appearanc
ewings sarcoma
sunburst pattern
osteosarcoma
does erythema blanche?
no
what is petechia?
> 2mm of flat purpura
is a nodule bigger than a papule?
yes
does roseace have comedones?
no
at what size does a skin lesion become concering?
> 6mm
what are the symptoms of ramsay hunt?
shingles in ear
pemphigus nikolsky sign
positive
pemphigoid nikolsky sign
negative
what is koebner phenomenon?
psoriasis / vitiligo on trauma areas
what sort of deramtitis is gloves?
allergic
what sort of dermatitis is soap
irritant
what cells are found in the granular layer and what do they contain?
large keratohyaline granules
which contain filagrin adn involcurin proteins
- odland bodies
which layer are the nuclei lost?
granular layer
which cells are found in the prickle layer?
langerhan cells
which layer is mainly composed of fibroblasts?
dermis
what do panician nerves sense?
pressure
what do meissener nerves sense?
vibration
aprocine sweat glands
armpits
oily + odourous fluid
eccrine sweat glands
palm and soles
what are the 2 dendritic cells in the dermis?
dermal DC - involved in Ag presenting and secreting cytokines
plasma DC - produce INFa (found in psoriasis)
pathway of vitamin D
what converts it?
stored at hydrocholecalciferol in the liver and changes to 1,25dihydroxycholecalciferol in the kindey
converted by 290nm UV light
T2 hypersensitivity examples
haemolytic disease of the newborn
blood transfusion recipients
T3 hypersensitivity examples
skin resting in arthurs reaction
T5 hypersensitivity examples
tuberculin reaction
contact allergy
delayed (1-2 days after contact)
deficiency in PCT
uroporphyrinogen decorbxylase –> increased uroporphyrinogen 3
symptoms of PCT
blistering in sun exposed areas milla hyperpigmentation hypertrichosis solari urticaria morphoea
peak for PCT
617mm
urine colour for PCT
red
deficiency for EP
ferrochelatase –> increase in protopyrin IX
symptoms of EP
erythema swelling itching burning pain
peak for EP
634mm
treatment for EP
antioxidants
deficiency for ATP
porphobillinogen deaminase –> increased PBG
symptoms of ATP
abdominal pain
urinary symptoms
psychiatric symptoms
proximal muscle weakness
treatment for ATP
hermatin + haema arginate (in acute attack)
which drug / base combo is the best for skin?
lipophilic drug + hydrophilic base / vehicle
3 modes of action of topical corticosteroids?
vasoconstrictive
antiinflammatory
antiproliferative
20-30g of topical corticosteroids =
1 fingertip = 2 hand areas
side effects of topical corticosteroid use
skin thinning
purpura
stretch marks
sudden removal - risk of rebound pustular psoriasis
what do calcineural inhibitors do
suppress lymphocyte activatoin
- used in atopic eczema
hyperkeratosis
increased thickness of keratin layer
parakeratosis
persitence of nuclei in the keratin laer
acanthosiss
increased thickness of epithelium
papillomatosis
irregular epithelial thickening
spongiosis
oedema fluid between squames appears to increase prominence of intercellular prickles
pathophysiology behind lichenoid disorders?
damage to basal epidermis eg lichen planus
pathophysiology behind pemphigus?
IgG antibodies made against desmoglein3
pathophysiology behind pemphigoid?
IgG reacts with hemidesmosomes which anchor basal cells to basement membrane
halotype of dermatitis herpetiform
HLA DQ2
how to treat a small area of ring worm?
comitrazole cream
how to treat a large area of ring worm?
terfinabine orally
how to treat candida
clotimazole
what is shingle for >4 weeks called
post hepatic neuralgia
when shingles is latent where does it sti
dorsal sensory root
where do adults get shingles
thoacic and lumbar nerves
where do cihldren get shingles
cervical and sacral nerves
what is ramsay hunt syndrome
VSV in 7th + 8th CN
vesicles + pain in auditory canal + throat
faical palsy
deafness, vertigo, irritation
what is the mechanism of acyclovir?
guanoside analogue
symptoms of erythema multiform
target lesions
molluscum contagiosum
fleshy firm unbilicated nodiles (1-2m in diameter)
children / sexually transmitted
treatment - liquid nitrogen
HPV types for genital warts
6+11
HPV types for cervical cancer
16+18
cause of herpangina
coxsackie / echo virus
cause of hand foot and mouth
coxsackie
cause of slapped cheek / erytheam infectiniosum
parovirus 19
primary infection of syphilus
chancre (painless ulcer at site of entry)
secondary infection of syphillus
red rash over body
prominent on soles of feet and palms
mucous membrane ‘snail track’ ucler
cause of syphillus
sexually transmitted bacterium troponaema pallidum
pruriceptive itch
somethign in skin triggers itch eg insect bite / lichen plnus
neuropathic itch
damage to nerves causing itch
neurogenic itch
no damage to CNS but itch caused by opiate effects on CNS receptors
psychogenic
psychologic cause with no CNS damage eg delusion of infestation
which secondary infection is common in atopic eczema?
staph aureus
crusting is characteristc
pomphylax eczema?
spongiotic vesicles
drug related eczema
eosinophils involved
lichen simplex eczema
due to scratching
stasis dermatitis
RBCs infiltration into extracellular compartment
symptoms of tuberous sclerosis
periungual fibroma longitudinal ridging infantile serizures (corical tuberous and/or calcification of falk cerebri) ash leaf macule (earliest sign) harmatomas shagreen patches enamel pitting
genetics of tuberous scelorsis
autosomal domiant
TSC1 (tuberin) + TSC2 (hamaratin) = tumour suppressor genes
types of epidermolysis bullosa
- simples - epidermis
- junctional - junction
- dystrophic (dermis)
features of neurofibromatosis 1
cafe au lait macules (>5 = abnormal)
neurofibromats
axillary freckling
optic glioma
what does a fillagrin mutation cause
itchythosis vulgaris
what is a malignant melanoma
found in basal layer
migrate into skin from neurla crest
what is a melanoma in situ called?
letingo maligna
what are the 2 types of malignant melanoma?
superficial - horizontal then vertical
nodular - vertical first (faster at progressing)
which genes mutate in malignant melanoma?
CDK2NA
CDK4
BRAF mutation
treatment for malignant melanoma
vemurafenib (targets RAF/RAS pathway)
transemitibin (targets MEK pathway)
what are some features of BCC
75% of all skin cancers painless slow growing pearly/ translucent visible blood vessels >40
which mutation is involved in BCC?
PTHC1 (drosphila gene pathced) - key component in the hedgehog pathway
what are some features of squamous cell carcinoma?
20% of all skin cancers warty/ crusted sun damaged skin can travel in nerves (merkel) poor prognosis + can met
what are SCC precursor lesions?
actinic keratosis (elongated rete ridges) bowens disease (scaly, erythematous plaques, irregular bored)
what are the high risk sites for SCC
ear
scalp
lip
what is UVA
- 320-400mm
- indirect oxidant damage
- penetrates further into skin than UBV
- penetrates through glass
in UVA, what are the pyramid dimers inbetween bases caused by?
oxidation of DNA bases eg deoxyguanosine
what os UVB
290-320nm
causes direct DNA damage
more damaging than UVA
what are acitninc lentinges?
age/liver spots
epidermis elongated riges
increased melanin and basal melanocytes
what are the 4 types of malenocytic naevi?
congenital
acquired
dysplastic naevus
rare naevi
describe congenital melanocytic naevi?
small <2cm
large >20 - risk of melanoma
describe aquired melanocytic naevi?
common during infancy
melanocyte : keratinocyte ratio breaks down
describe dyspalsic naevi?
> 6cm in dimaeter
asymmetric
sporadic or familial
what are the 3 types of rare naevi?
halo - depigmented peripheral halo, overrun by lymphocytes
blue - dermal, pigement rich dendritic spindle cells
spitz - <20 years, large
what are the 4 types of malignant melanoma?
superficial
acral / mucosal - heels fingers toes nails
lentino maligna
nodular
what are seborrheic keratosis?
benign (version of BCC)
face and trunk
stuck on apperance (greasy)
what is a malignant sign of seborrheic keratitis?
lesser treat
what are the results of ABPI?
1 = normal 0.8-1.3 = compression <0.8 = vascular disease >1.5 = calcification
decribe an arterial ulcer?
pressure areas eg feet toes
deep, punched out, not weepy, necrotic base
swings legs off bed
describe a venous ulcer?
medial and lateral malleolus most common
knee to foot
pain
which cells carry out vitamin D metabolism?
keratinocytes
type 2 hypersensitivity
direct cell killling
type 3 hypersensitivity
immune complex mediated
which inheritance pattern is tuberous scelrosis
autosomal dominnat
which numbers of HIV are for warts / verucas
1-4
which symptom is present months before bullous pemphigoid?
itch
what is the treatment for roseaca?
metronidazole gel
2. oral tetracycline
what is the definition of breslows thickness
the depth from the granular layer of the epidermis to the deepest melanoma cells
which surgery technique gives the best outcome?
an elliptical excision with the scalpal cutting at 90 degrees to the surface of the skin
