Skin Conditions Flashcards
Autoimmune condition that destroys the melanocytes in the skin
Vitiligo
Possible future Treatment for vitiligo =
Works by _____
May potentially cause increased risk of _____
Melanotan
Short tripeptide of hormone that stimulates melanin production
Melanoma
MSH excess from pituitary =
Nelsons syndrome - hyperpigmentation
AI loss of pilosebaceous units as follicles are attacked
Alopecia areata
Inherited DEJ disease 2 types =
Epidermolysis bullosa simplex and dystrophic (EBS and EBD)
Acquired DEJ conditions due to auto-antibodies
Pemphigoid
Pemphigus
Dermatitis herpetiformis
inherited condition that causes breakdown of the skin barrier due to impaired cholesterol synthesis
Steroid sulfatase deficiency X-linked ichthyosis
Psoriatic plaque eruption caused by minor skin trauma =
Koebner’s phenomenon
atopic eczema lesions usually contain:
Th2, dendritic cells, keratinocytes, macrophages and mast cells
Pemphigus/pemphigoid are examples of type __ hypersensitivity reaction
type 2
purpura/rash are examples of type ___ hypersensitivity reaction
3
urticaria is a type __ hypersensitivity reaction
1
erythema/rash is a type ___ hypersensitivity reaction
4
symmetrical skin erupion of sudden appearance - suspect ___
drug induced
exanthematous drug reaction is a type __ reaction that is ___ mediated
causes a ____ rash
type 4
t cell
widespread symmetrical
drugs that cause exanthematous drug reaction =
penicillins sulfonamide antibiotics erythro/streptomycin allopurinol anti-epileptics (carbamazepine) NSAIDs phenytoin chloramphenicol
urticaria is usually a type __ hypersensitivity reaction mediated by ___ after rechallenge
examples of drugs that cause this =
1
IgE
beta lactam antibiotics, carbazepine
urticarial reaction on first exposure to the drug is caused by ___
examples of drugs that cause this =
mast cells releasing inflammatory mediators
vancomycin, NSAIDs, aspirin, opiates, muscle relaxants, quinolones
drugs that can cause acne as an adverse reaction
glucocorticoids, androgens, lithium, isoniazid, phenytoin
AGEP =
(very rare) drugs that cause this adverse reaction =
acute generalised exanthematous pustulosis
antibiotics, CCBs, antimalarials
drug induced bullous pemphigoid caused by
ACEI, penicillin, furosemide
drug induced linear IgA disease caused by
vancomycin
describe the appearance of fixed drug eruptions
well demarcated, round/ovoid plaques
red and painful
usually mild and a single lesion
can be eczematous, papules vesicles or urticaria
common locations of lesions of fixed drug eruptions
hands, genitalia, lips and occasionally oral mucosa
drugs that can cause fixed drug eruptions
vancomycin, doxycycline, paracetamol, NSAIDs, carbamezepine
DRESS stands for ___
it is a severe cutaneous adverse reaction, drugs that cause =
drug reaction with eosinophilia and systemic symptoms
sulfonamides, anticonvulsants, allopurinol, minocycline, dapsone, NSAIDs, abacavir, nevirapine, vancomycine
TEN and SJS are severe cutaneous adverse reactions
drugs that cause them =
Toxic epidermal necrolysis Stevens Johnson Syndrome
sulfonamide Abx, cefalosporins, carbamazepine, phenytoin, NSAIDs, nevirapine, lamotrigine, tramadol, pantoprazole
T/F phototoxic drug reactions can occur through windows?
True
Usually UVA or visible light
Phototoxic drug reactions are ___ mediated
mechanism behind them = appropriate wavelength hits ___ under surface releasing __+__
non-immunological
drug chromophore
free radicals and photoproducts
acute phototoxic drug reactions =
skin toxicity, systemic toxicity and photodegradation
chronic phototoxic drug reactions =
pigmentation, photoaging and photocarcinogenesis
typical manifestations of Type 1 hypersensitivity reaction
anaphylaxis eczema asthma hives hayfever urticaria angioedema
dermatological examples of type 4 hypersensitivity reactions
contact dermatitis
tubercular lesions
graft rejection
In type 1 HS reactions: Th2 produces ++_ that stimulate B cells to produce ___ which then ___
IL4, 5 and 13
IgE
becomes Fce receptor on mast cell
In type 1 HS urticaria appears within __ and lasts for __
1hr
2-6/24 hrs
Investigations for suspected type 1 HS reaction
RAST - blood test for specific IgE
skin prick and if it is negative = challenge test
serum mast cell tryptase level (during anaphylaxis)
doses of adrenaline in epipens for anaphylactic shock
adults = 300microg kids = 150microg
Drugs that can be used day to day if have a type 1 allergy
mast cell stabilisers - sodium cromoglicate
In type 4 HS skin reactions: ___ T cells cause apoptosis of __ and produce ___+___ causing ____
CD8+
keratinocytes
chemokines and cytokines
leukocyte recruitment
Gold standard test for suspected allergic contact dermatitis
patch test
treatment for allergic dermatitis
minimise exposure to allergen emollients topical steroids UV phototherapy immunosuppressants
mode of inheritance of tuberous sclerosis
auto-dom or de novo
earliest cutaneous sign of tuberous sclerosis
ash-leaf macule - depigmented
pathognomic of tuberous sclerosis
periungal fibromata
s+s of tuberous sclerosis
infantile seizures longitudinal nail ridging periungal fibromata facial angiofibroma cortical tubers +//- calcification of falx cerebri may => seizures angiomyolipomas bone cysts Shagreen patch enamel pitting
3 types of epidermolyis bullosa
simplex
junctional
dystrophic
characteristic of simplex epidermolysis bullosa
epidermal
light grazes and blisters
doesn’t cause scarring
characteristics of junctional epidermolysis bullosa
blistering and ulcers
may scar
characteristics of dystrophic epidermolysis bullosa
dermal and causes scarring
digits shorten causing mitten hands if not bandaged separately
EB aquisita is rare and caused by ___
AI against collagen 17
cafe au lait spots, axillary freckling, optic glioma, Lisch nodules are characteristic of
NF1
filaggrin loss of function mutations can cause:
leratosis pilaris
hyperlinear palms
ichthyosis vulgaris ( auto dom - fish scaling due to loss of granules in granula layer)
filaggrin mutations increase your risk of : (3)
eczema x4
asthma and hayfever x3
peanut allergy x5
ratio of melanocytes:basal cells at DEJ
1:10
2 components of skin basement membrane
laminin and collagen 4
an example of a spongiotic inflammatory skin reaction
eczema
elongation of the rete ridges = ___ inflammatory skin reaction
psoriasiform
auspitz sign in psoriasis =
pick off plaque and bleeds as vessels are close to surface
pemphigus vulgaris is a loss of the integrity of ___
epidermal cell adhesion
pemphigus vulgaris basis of AI =
IgG auto-Ig against desmoglein 3 (maintains desmosomal attachments) =>immune complexes> complement and protease > desmosomes disrupted > acanthosis
Characteristic of lesions caused by pemphigus vulgaris
fluid filled blisters which rupture to cause shallow erosions
bullous pemphigoid causes a ___ blister with no sign of ___
subepidermal
acanthosis
AI basis of bullous pemphigoid =
IgG attack hemidesmosomes that anchor basal cells to basement membrane
immunofluorescence in bullous pemphigoid shows:
linear IgG and complement around basement membrane
lots of eosinophils
histology of bullous pemphigoid shows:
fluid and inflam cells between basal cells and dermal papilla projectinto bulla
dermatitis herpetiformis is associated with ___ disease and ___ gene
coeliacs
HLA-DQ2
AI bullous disease that causes v itchy symmetrical lesions on elbow knees and buttocks
dermatitis herpetiformis
hallmark of dermatitis herpetiformis
papillary dermal microabscesses - deposits of IgA
Lichenoid inflammatory skin reactions are characterised by
damage to basal epidermis
examples of lichenoid inflammatory skin reactions
lichen planus
discoid lupus
drug rashes
characteristics of lichen planus =
ithcy flat topped violaceous papules irregular sawtooth acanthosis hypergranulosis, orthohyperkeratosis melanocytes drop out upper dermal infiltrate of lymphocytes cytoid bodies
comedones =
build up of keratin and sebum in pilosebaceous units
aggravators of rosacea
sunlight
alcohol
spicy foods
stress
characteristics of rosacea
recurrent facial flushing
visible blood vessels
pustules
rhinophyma
follicular ___ are often present in rosacea
dermodex mites
histology of rosacea =
vascular ectasia
patchy inflam with plasma cells
perifollicular granulomas
sites on the body of psoriatic plaques
extensor surfaces
scalp sacrum, hands, feet, trunk, nails
auspitz sign is in ___ (condition)
caused by
psoriasis
dilated capillaries in elongated dermal papillae
4 subtypes of psoriasis
vulgaris (chronic plaque)
guttate
palmoplantar pustular
erythrodermic/widespread pustular (rare)
guttate psoriasis is commonly set off by
strep infection
nail signs of psoriasis
pitting
dystrophy
onycholysis
subungal hyperkeratosis
systemic factors associated with psoriasis
increased systemic inflam markers psoriatic arthritis metabolic syndrome Crohn's cancer depression uveitis
topical treatments for psoriasis
vit D analogues (calcipotriol/calcitrol) coal tar dithranol steroids emollients
treatments for psoriasis (non-topical)
Phototherapy (UVB narrowband and pUVA)
IS - methotrexate
biological agents
features of mild acne -
scattered papules and pustules - mild atrophic scarring
features of moderate acne -
numerous papules and pustules and mild atrophic scarring
features of severe acne -
cysts nodules significant scarring
topical treatments for acne
benzoyl peroxide
retinoids
tetracyclines
properties of benzoyl peroxide that make it good for acne treatment
keratolytic
antibacterial
systemic drugs for acne
antibiotics
isotretinoin
type of drug that isotretinoin is and its effect in the Rx of acne
oral retinoid
affects sebaceous gland activity - initially aggravates acne - lots of side effects
eye problems that can be ass with rosacea
conjunctivitis
gritty eyes
topical treatments for rosacea
metronidazole
ivermectin
mech of action of ivermectin in rosacea Rx
decreased dermodex mite population
in rosacea there are no ___ on the skin as isnt a disease of pilosebaceous unit
comedones
oral Rx for rosacea
tetracycline
isotretinoin low dose if severe
Rx for 1 telangiectasia and 2 rhinophyma in rosacea
1 vascular laser
2 laser shaving/sx
Wickham’s striae appearance
An example of a ___
white reticular network on
lichenoid eruption
shiny flat-topped pink/purple papules and plaques = an example of a __
lichenoid eruption
sites that lichen planus typically affects
volar wrist and forearm
shin
ankles
lichen planus usually lasts ___
12-18mnths - burns itself out
treatment of severe itch in lichen planus
topical potent steroid, oral if extensive
which is deeper and which is more superficial out of bullous pemphigoid and pemphigus vulgaris
Deeper = pemphigoiD Superficial = pemphiguS
bullous pemphigoid causes a split in the __ pemphigus vulgaris in the ___
BP = DEJ PV = intra-epidermal
nikolsky sign =
differentiates between __+__
when rubbed lightly on top the skin slips away
+ve = pemphigus vulgaris
-ve = pemphigoid bullosa
large tense bullae on normal skin with erythematous base = ___ (condition)
pemphigoid bullosa
mucosal lesions are unlikely in pemphigoid bullosa/pemphigus vulgaris
pemphigoid bullosa
it’s very common in PV
flaccid vesicles/bullae that rupture to leave raw area with increased infection risk = ___ (condition)
pemphigus vulgaris
PV and BP are ___ and last ___, remission on Rx in ___
self-limiting in months-yrs
3-6mnths
mortality rates for BP and PV
PV = high mortality if untreated BP = lower risk
Ix for BP and PV
biopsy with direct immunofluorescence
indirect immunofluoroscence
treatments for BP and PV
systemic steroids
IS agents
topicals: emollients, steroids, antiseptics
tetracycline (BP)
treatment for boil with surrounding cellulitis
flucloxacillin PO 1g qds
pyoderma gangrenosum is ass with __+__ and usually affects the ++_
UC and Crohn’s
legs, trunk and stoma
patient returns from abroad with a rash that after 1-2 days leads to painful sores =
hand, foot and mouth
describe lesions of dermatitis and eczema
itchy, ill-defined, scaly and erythematous
acute phase of dermatitis and eczema lesions=
papulovesicular, red, spongiosis, ooze/scale/crust
chronic phase of dermatitis and eczema lesions =
lichenification, elevated plaques, increased scaling
histology and pathogenesis of contact allergic dermatitis
type 4 hypersensitivity
spongiotic dermatitis
histology and pathogenesis of contact irritant dermatitis
spongiotic dermatitis
trauma eg. soap and water
histology and pathogenesis of atopic eczema
genes and envnt => inflam
spongiotic dermatitis
histology and pathogenesis of drug induced dermatitis
type 1+4 HS reaction
spongiotic dermatitis with eosinophils
histology and pathogenesis of photo-induced dermatitis
reaction to UV
spongiotic dermatitis
histology and pathogenesis of lichen simplex dermatitis
physical skin trauma eg. scratching
spongiotic dermatitis and external trauma
histology and pathogenesis of stasis dermatitis
physical skin trauma - hydrostatic pressure
spongiotic dermatitis and extravasation of RBCs
atopic eczema distribution in babies
often wide spread
cheeks and extensors
appearance of herpeticum =
caused by __ infected with ___
monomeric punched-out lesions
eczema infected by herpes simplex
diagnostic criteria for eczema -
itching +>= 3 of: visible+/Hx of flexural rash generally dry skin Hx atopy onset <2yo
treatments for eczema
emollients topical steroids treat infection UVB mainly phototherapy systemic IS
appearance of discoid eczema
itchy, red, swollen and cracked in circular/oval patches
chronic actinic dermatitis causes a photosensitive reaction in ____ = type __ HS
24-72hrs
type 4
drug induced photosensitive eczema causes reaction in ___ type of reaction = ___
mins-hrs
exaggerated sunburn
stasis eczema is 2ndry to ____
site = ___ and may lead to ___/___
hydrostatic pressure, oedema, RBC extravasation
lower legs
ulceration and hyperpigmentation
cradle cap in infants or dandruff =
seborrhoeic eczema
appearance of pompholyx eczema
spongiotic vesicles on hands/feet
