derm Flashcards
what is les trelat sign
sudden multiple sebborheic keratosis
indicative of cancer
sebborheoic keratosis rx
cyrotherapy and curettage
dermatofibroma rx
only excise if sx
dermatofibroma description
firm elevated nodules like buttons. peripheral ring of pigmentation
often in those with hx insect bites or trauma
describe epidermal cysts
cysts with central punctum
contains caseous keratin
dermal inflammation
where do you get pyogenic granulomas and what do they look like
red often on finger
what are keratocanthomas
epidermal tumours with central necrosis and ulcers
what are acitinic keratosis
red and silver papules or patches scaly, with conical base and red base
rx acitinic keratosis
cryo, 5FU (5% diclofenac or imiquimod) or none if nor bothering
bowens disease is in which part of the skin
epidermis
what can keratocanthomas develop to
scc
what diameter of melanocytic naevi is suspicious for ca
7mm
where are superficial spreading melanomas commonly found. what is there cause
- LL
- intermittent high intensity UV exposure
cause of nodular melanoma
- intermittent high intensity UV exposure. most common trunk
cause of lentigo maligna melanoma
- cumulative UV exposure in elderly
kaposis sarcoma rx
radiotherapy and resection
drugs that cause IgE reactions
ET is a nuisance because he pees a lot and has cell phone, a pen and a strong muscle;
- NSAID
- Sulphonamides
- Penicillin
- Muscle relaxants
- Diuretics
what kind of rash do you get with toxic erythema and how long does it take to manifest after drugs taken
- maculopapular
- within 2 weeks
drugs that cause urticaria
- nsaids
- ace-i
- pen and ceph
- codeine and morphine
which drugs give you widespread eythroderma
cages give you erythroderma;
- carbamezapine
- Allopurinol
- Gold
- Sulphonamides
what is a fixed drug eruption
- skin reaction of blistery style rash at same site on skin everytime a specific drug is taken
- leaves purply hyperpigmentation and re erupts at same site on re exposure to drug
- arrive over few hrs from exposure
drugs that commonly cause fixed drug eruptions
- PTSA
- Paracetemol
- Tetracycline
- Sulphonamides
- Aspirin
commonest cause of erythem multiforme
HSV
prodrome to erythema multiforme sx
fever, coryza
ix for drug reactions particualrly SJS and TENS
- biopsy - epidermal detachment
- FBC, U and E, ABG, LFT; can cause resp compromise if mucosal involvement in U/L airways
- blood cultures to rule out TSS and SSS; staph/ strep cultures
How to treaet TEN
- derm/ burns unit
- IV supportive care for haemodynamic stability
- STM dexamethasona pusle therapy, IVIG
define SJS
- Mucucutaneous necrosis with at least 2 mucosal sites involved
presentation of SJS
- Resp sx 2-3 / 52 after starting drug. approx 2 days before a rash that effects <10% body
- painful erythematous macules –> target lesions
cause of SJS
- Drugs
common cause of TENs
- drugs
sx of TEN
- extensive skin and mucosal necrosis and systemic toxicity
what is nikolskys sign
sloughing off epidermal layer when pressure applied to erythema or blisters
SJS drugs causes
PABENS-TG cause SJS -
- Penicillins
- Anti - epileptics
- Antimalarials
- BB
- NSAIDs
- Suphonamides
- thiazides
- GOLD
Drugs that cause TEN
CAANMPS -BTG - Cephalosporins - Anti-epileptics Anti-malarials - Allopurinol - NSAIDs - Penicillins - Sulphonamides - BB -thiazides - Gold
difference between SJS and erythema multiforme
erythema multiforme is the precursor and in SJS there is extensive necrosis
difference between SJS and TEN
TEN has sytemic toxicity and is full thickness necrosis.
cause of death in TENS and SJS
- Sepsis
- Electrolyte abnormalty
- organ failure
3 phases of follicle cycle for growth
- anagen ; long growing phase
- catage - short regressing
- telogen - resting/shedding phase
3 types of hair
- lenugo; coarse long in fetus
- vellus; fine and short, whole body
- termina; eyebrows, scalp, lashes, pubic
impetigo causes
- GAS
- Staph
impetigo rx
- GAS = pen v
- Staph = fluclox
- usually fusidic acid 2% is enough, then mupirocin. if extensive then above abx given
what are the stay at home rules for kids with impetigo
- stay home till lesions crust
difference between staphylococcal scalded syndrome and bullous impetigo
- SSS is systemic.
- BI = local
both caused by staph; toxin A = local. Toxin B = systemic
what age group is SSS seen in most
- infancy and early childhood
SX of SSS
Few hrs to days - worse over the face, neck. axillae and groin
how long does it take to recover from SSS
- 5-7/7
rx SSS
- Fusidic acid, erythromycin
RF for erysipelas and cellulitis
- immunsupression
- ulcers
- wounds
- toeweb iretrigo
- minor tinea pedis
- lymphoedema
what causes erysipelas in DM
Staph
what causes erysipelas normally
- GAS
what causes folliculitis
strep
what is a furuncle and what is the rx
- boil
- infected hair follicle
- oral fluclox and I and D
What is nec fascitis
- rapidly progressive necrosis of subcutis and fascia = rapidly spreading
- check for gas ins subcut fascia in XR
rX NEC FASC
- Fluids
- high dose abx - meropenem and clindamycin
- surgical debridement
what is special about ptyrisis versicolor in terms of sx
- scaly pale brown patches on upper trunk that fail to tan on sun exposure
what makes pityriasis versicolour worse
- steroids
treatment of pitryriasis versicolour
- ketoconazole shampoo or topical antifungalm pigmentation
what causes pityriasis versiclour
- fungus; mallasezia furfur
- Scabies rx
- permethrin - apply at night from neck down and wash in morning
what is the commonest bed bug
- cimex lectularius
what to do bed bug bites look like
- pruritic, erythematous, oedematous papules - central punctum
rx bed bug bites
nothing as self limiting after 7/7
or mild steroid cream/ .antihistamine if itchy
where do you find sebborhoeic dermaittis
- scalp
- eyebrows
- nasolabial folds
- cheeks
- flexures
cause of seborrheoic dermaittis
- skin yeasts overgrowths e.g. malassaezia.
- more severe in HIV patients
rx sebborhoeic dermatitis
- mild topical steroids/ antifungals = daktocort/ ketoconazole shampoo
which t cells induces ige response in eczema
th2
eczema diagnostic criteria
- <2yrs of age
- flexural involvement in the past
- personal hx or fhx if <4yrs of age
- visible flexor dermatitis
to dx need ithcy skin +3/>3
side effects of aciclovir
- GI upset
- LFT abnormalitiyes
- neurological abnormalities
- haem
h1R antagonist names
- cetirizine
- loratadine
- chlorphenamine
name the two retinoid that can be given for acne, psoriasis and disorders of keratinisation
- isotretinoin
- acitretin
SE retinoids
- LFTs disorders
- depression
- dryy skin. lips. eyes
- high cholesterol and TG
- myalgia
- arthralgia
- teratogen
what should you do about contraception if on retinoids
be on contraception 1 month before, during and 1 month after if iso.
be on it for 2 yrs after if acite
why are retinoids used in skin disorders
- encourages prompt surface skin cells turnover and binds to receptors to modify follicular keratinisation; tretinoin
what does molluscum contagiosum look like
- pearly white papules with central umbillication
- rx - aciclovir
define erythroderma
- widespread erythema and dermatitis affecting >90% body surface
- scaly and oedema
- sytemically unwell with LNA and malaise
erythroderma rx
- derm refer
- emollients
- wet wraps
- topical steroids
how to treat eczema herpeticum
IV aciclovir
atopic ecczema rx ladder
- emollients and lifestyle
- topical
- steroids
- tacrolimus (steroid sparing but causes burns, pruritus and acne)
- antihistamines to prevent itching - phototherapy
- systemic agents; steroids, ciclo, azithro, metho
- biological agents; dupilumab
SE ciclosporin
- hepatotoxic
- nephrotoxic
- fluid retention
- gingivitis
- IGT
SE azathipprime
- myelosupression
- N and V
- pancreatitis
- non melanoma sc
psoriasis - triggering drugs
- Stop the heart; BB and ACE-i
- stop the pain - NSAids
- stops me going insane - Lithium
- stop the inflame - steroids, interforons, TNF
- stop the bac with a tic tac - tetracyclines
- stop the bites from the mites = antimalarials
treatment ladder psoriasis
- emollients + steroids + vit D analogue. max 4/52 streoids
- vit D analogues BD
- Potent steroids 4 weeks OR coal tar
- short acting dithranol +/- refer
- in secondary care - phototherpay
- methotrextate, ciclosporin, retinoids esp if joints involved
why does vit d analogue help in psoriasis
- inhibit hyperproliferation of epidermis and differentiation of kertatinocutes
vit d analogue SE
- Itchy
- erythema
- burning
- paraesthesia
- dermatitis
phototherapy MOA in psoriasis
- apoptosis
- reduced cytokines
- promote suppression
SE retinoids
- teratogen
- dry skin
- mucosa
- increase dlipids
- lower glucose
- increase LFT
what happens to foetus exposed to retinoids
foetal retinoids syndrome
- growth delay before and after birth IUGR
- Craniofacial abnormalities
- hydrocephalus
- TOF
what are the 4 types of psoriasis and which are an emergency
- guttate - kids, post strep
- plaque - silvery
- erythrodermic - emergency
- pustular - not infectious but emergency +/- systemic upset
what cells cause autoimmune issues of psoriasis
TH17
guttate psoriasis most commonly appears on which part of the body
trunk and limbs
what are the koebner and auspitz phenomenon
- koebner = areas of trauma get plaques
- auspitz - attacked areas bleed if scratched
what type of nose do you have in systemic sclerosis
beak shaped
what are the two types of porphyria
- acute
- cutanea tarda
symptoms of acute porphyria
- hepatic porphyrias
- CNS - muscles weakm seizure, mental disturbance
- abdo pain; vomit
- cardiac arrythmia
- acute neuropathy
symptoms of cutanea tarda
- dermatitis; photosensitive
- blisters
- skin necrosis and gums
- itchy and swelling and increased hair growth on forehead
IBD common skin manifestation
- erythrema nodosum
- pyoderma gangrenosum
chromosome affected in Neurofibromatosis T1
17
CHR affected in neurofibramotosis T2
- 22
sx NF1
- lisch hamartomas; eye nodules
- phaeochromocytomas
- cafe au lait spots
- peripheral neurofibromas
- freckles in axilla and groin
- scolioiss
sx NF2
- Schwannomas esp IC and bilateral vestibular
- acoustic neruomas
cause of neurofibromatosis
- uncoontrolled proliferation of neural crest cells
sx tuberous sclerosis
- ash leaf spots
- retinal hamartomas
- seizures
- Intellectual disability
- developmental delay
- shagreen patches/ peau de orange
commonest cause of erythema multiforme
HSV
types of pyoderma gangrenosum
- classical in immunosupressed. legs and trunk. can be explosive onset and rapid spread with pain and illness. or indolent and slow spread from one area to another
- peristomal; around stoma
- vegetative - single well healing in healthy patients. good response to topicals . head an neck common
- bullous; in haem disease.
- pustular - IBD
- genital
define papule
palpable noduel <0.5cm
define nodule
papule >0.5cm
what causes bullous pemphigoid
- autoantobodies between dermis and epidermis - IGG
Rx for bullous pemphigoid
- steroids topical
- then oral
sx bullous pemphogoid
- blistering skin. tense; fluid filled on an erythematous base
- itchy
- trunk and limbs, not often mucosal
sx pemphigus
- burning and pain
- mouth often involved
- flaccid and easy rupture unlike pemphigoid
- face, torso, flexors
what does nikolskyys sign indicate
- pemphigus; applying pressure with finger to bulla causes displacement
how to diagnose pemphigus
skin biopsy - loss of interccellular connections between cells and epidermis
- IgG on immunoflurosecence - autoabs
how to diagnose pemphogoid
skin microscopy = itnact subepidermal blisters
rx pemphigus
- emergenct
- immunosupress - prednisolone and azathioprine. give pred till reduced blisters
- oral lesions - steroid mouthwash
dermatitis herpetiformis rx
- dapsone. but check g6pd
polymorphous light eruption typically effects whom
- young women in sprign after light exposure
rx polymorphous light eruption
- steroids
- severe - UVB phototherapy
triggers of porphyria cuntanea tarda
- high oestrogen
- high iron
- low ascorbic acid
- hep c
- alcohol
- HIV
signs of cutanea tarda
- vesicles/bullae in sun exposed sites, hyperpigmentation
ix results in cuanea tarda
- high LFT
- High ferritis
- high plasma
- high faecal and urinary prophyrins
rx cutaenea tarda
- sun avoid
- avoid precipitants
- regular venesection till ferritin normal;
- chloroquine
- ascobic acid
rx venous ulcer
- compression bandaging if no arterial insufficiency
why should you XR a neuropathic ulcer
- to check for osteomyelitis
rx SCC on skin
<20mm diameter = surgical excision with 4mm margins
> 20mm = 6mm margins
high risk = mohs
