MedEd derm Flashcards
when describing lesions what are the 3 types?
flat
fluid filled
raised
what are the types of flat skin lesions and how do they differ?
macule= small patch= large
what are the types of fluid filled skin lesions and how do they differ?
vesicle= small ie <0.5cm diameter bulla= large ie >0.5cm diameter pustule= pus filled
what are the types of raised skin lesions and how do they differ?
papule= small ie <0.5cm in diameter nodule= large ie >0.5cm diameter
what type of skin lesions are macules and patches? how do they differ?
flat skin lesions
macules are small
patches are large
what type of skin lesions are pustules, vesicles and bullae? how do they differ?
raised
pustule= pus filled
vesicles= <0.5cm
bullae= >0.5 cm
what type of skin lesions are papules and nodules? how do they differ?
raised
papules are small
nodules are large
what is squamous cell carcinoma?
cancer of keratinocytes in the epidermis
what is the most common and second most common skin cancer?
most common= basal cell carcinoma
second most common= squamous cell carcinoma
what is the nature of invasion in squamous cell cacinoma?
local invasion into the dermis
can metastasise, common sights are lung, bone, brain and liver
what is basal cell carcinoma?
cancer of keratinocytes in the epidermis in the stratum basale
what are rf for squamous cell carcinoma?
UV light
fhx
lighter skin
actinic keratosis
what are rf for basal cell carcinoma?
UV light
fhx
lighter skin
what condition might increase risk of someone developing squamous cell carcinoma?
actinic keratosis
what is the nature of invasion in basal cell cacinoma?
slow growing local invasion into the dermis and doesnt metastasise
what does basal cell carcinoma look like?
nodule
pearly edges
central ulcer called a rodent ulcer
central fine telangiectasia
what is found at the center of a basal cell carcinoma nodule?
rodent ulcer
out of basal and squamous cell carcinoma which metastasises?
squamous cell
what are the types of basal cell carcinoma and how might they differ?
nodular= most common, pearly edges with rodent ulcer and central fine telangiectasia superficial= flat morpheic= yellow waxy plaque, scar like pigmented= dense and specks of colour
what acronym is used to remember how you describe a lesion and what does it stand for?
ABCDE: asymmetry border colour diameter evolution
what is the most deadly skin cancer?
malignant melanoma
what is malignant melanoma?
cancer of the melanocytes in the epidermis
what are rf for malignant melanoma?
UV light
fhx
lighter skin
what is the nature of invasion of malignant melanoma?
local invasion into the dermis
can metastasise, common sites include lung, bone, brain and liver
what does a malignant melanoma look like (go via ABDE)
Asymmetrical Border is irregular Colour is pigmented (dark) Diameter is over 6mm Evolution- might bleed, itch, crust over, ulcerate
how quick does referral need to be done for malignant melanoma v squamous v basal cell carcinoma?
malignant melanoma= urgent within 2 weeks
squamous= urgent within 2 weeks
basal= routine within 6 weeks
what ix are done for skin cancer? why are they done
bedside= dermatoscope bloods= ALP to check for bone mets, LFTs to check for liver mets imaging= CT/MRI/PET for staging biopsy= measure breslow thickness so see melanoma invasion extent, good for prognosis
what is breslow thickness?
it is a measure of melanoma invasion which can help judge prognosis and is done when a biopsy is taken
what is measured when a biopsy is taken is skin cancer and why?
breslow thickness
it shows the extent of melanoma invasion and can help judge prognosis
how is squamous cell carcinoma managed?
if in situ= cryotherapy
if invasive= surgical excision and radiotherapy
how is basal cell carcinoma managed?
non cosmetically challenging= surgical excision
cosmetically challenging= moh’s surgery
how is malignant melanoma managed?
early stage= surgical excision and lymph node biopsy
advanced but resectable= surgery and systemic therapy with nivolumab
advanced= systemic therapy (nivolumab) and treat mets
what systemic therapy is used in skin cancer for advanced malignant melanoma?
nivolumab
what type of skin condition is eczema?
inflammatory (NOT autoimmune)
what are rf of eczema?
pmhx/fhx of atopy eg food allergy, hay fever, asthma
filaggrin gene mutation
what does eczema look like?
distributed in flexures
dry, itchy, erythematous skin
lichenification if its chronic
what feature might you see in chronic eczema?
lichenification
where is eczema distributed?
in the flexures
describe atopic dermatitis. what skin condition does it fall under?
eczema
type I/IV hypersensitivity
IgE mediated
in the flexures
describe contact dermatitis. what skin condition does it fall under?
type IV hypersensitivity, delayed
often nickel/latex
two types are irritant and allergic
what subtype of eczema is associated with nickel/latex?
contact dermatitis
describe discoid dermatitis. what skin condition does it fall under?
it is a subtype of eczema
associated with coin shaped plaques
more common in middle aged/elderly
what type of eczema is a medical emergency?
eczema herpeticum
what is eczema herpeticum superimposed by?
HSV 1
what type of condition is psoriasis?
autoimmune
what is psoriasis?
an autoimmune condition where there is hyperproliferation of keratinocytes
what cells proliferate in psoriasis?
keratinocytes
what are rf for psoriasis?
stress
smoking
alcohol
what are features of psoriasis?
nail signs: onycholysis, subungal hyperkeratosis, pitting
psoriatic arthritis: symmetrical polyarthritis
dry, scaly, itchy, erythematous plaques which are purple/silvery in colour on the extensor/scalp surfaces
what are some conditions where you might see onycholysis?
psoriasis
thyrotoxicosis
trauma
fungal infections
what is onycholysis?
painless separation of the nail from the nail bed
what do psoriasis lesions look like?
dry, scaly, erythematous, itchy plaques which are purple/silvery in colour
where re psoriasis plaques distributed?
on the extensor surfaces and scalp
what is the most common type of psoriasis?
plaque psoriasis
what test may be done to diagnose contact dermatitis?
skin patch testing
what test may be done to diagnose atopic dermatitis?
IgE-RAST
what test may be done to diagnose food allergies?
skin prick testing
how are guttate, pustular and plaque psoriasis managed?
guttate: 1st line phototherapy, 2nd line ciclosporin, 3rd line methrotrexate
pustular: 1st line acitretin, 2nd line ciclosporin
plaque: topical hydrocortisone
how is acute v chronic eczema treated?
acute= emollient with topical corticosteroid chronic= emollient with low potency corticosteroid
what is urticaria?
skin lesions that develop rapidly often from hypersensitivity reactions
often associated with angioedema
what is urticaria often associated with?
agioedema- swelling underneath the skin
what is angioedema?
swelling underneath the skin
what are triggers for urticaria?
allergen
viral infections- common in children
what does urticaria look like?
erythematous, not painful and non blanching
how long does it take urticaria to resolve?
usually within 24 hrs
acute <6 weeks
chronic >6 weeks
what ix are done for urticaria? why?
FBC- to establish baseline eosinophil count
CRP
ESR
how is urticaria managed?
identify the trigger
antihistamines (up to 6 weeks)
oral corticosteroids
what will be in an eczema sba?
lichenification
pmhx or fhx or atopy eg food allergy, hayfever
itchy, dry skin
distribution in flexures
what will be in a psoriasis sba?
purple/silver erythematous plaques that are itchy
distribution on extensor surfaces
onycholysis, subungal keratosis
what are cellulitis and erysipelas?
bacterial infections of the skin
what organisms is likely to be the cause of cellulitis and erysipelas?
strep pyrogenes most commonly
staph aureus
what similarities do cellulitis and erysipelas have in common?
acute onset
red, painful, hot, swollen lesions
what are rf for cellulitis and erysipelas?
wounds bites ulcers IV cannula immunosupression
how can you differentiate cellulitis and erysipelas?
erysipelas= lesion is epidermal, lesion is more well demarcated, more likely to have fever and rigors but sepsis is uncommon cellulitis= lesion is dermal, it is less demarcated/more patchy, systemic symptoms like fever/rigors are less likely but sepsis is more likely
out of cellulitis and erysipelas which is more likely to progress to sepsis?
cellulitis
what is the difference in location of infection between cellulitis and erysipelas?
cellulitis= dermis erysipelas= epidermis
what are complications of sepsis and which are surgical or medical emergencies?
abscess
sepsis- medical emergency
periorbital or orbital cellulitis- medical emergency
necrotising fasciitis- surgical emergency
how is periorbital or orbital cellulitis managed?
IV abx
what ix are done for cellulitis and erysipelas and what will you see?
usually diagnosis is clinical
skin swab MCS/ blood culture- strep pyrogenes positive
bloods- raised WCC, CRP
CT/MRI- if orbital cellulitis
how is cellulitis/erysipelas managed?
conservative= mark around the lesion, painkillers, monitor it
medical= oral abx, IV abx if near eyes
admit if they are septic or confused!!
when are IV abx used over oral in cellulitis/erysipelas?
if cellulitis is near the eyes
what is necrotising fasciitis?
a life threatening infection of subcutaneous soft tissue
what are signs and symptoms of necrotising fasciitis?
severe pain or anaesthesia over the sight
systemic signs= fever, tachypnoea, tachycardia, palpitations
warm, erythematous lesion with oedema which may turn violet
what does necrotising fasciitis look like?
warm, erythematous lesions with oedema that may turn violet
where is infection located in necrotising fasciitis?
subcutaneous soft tissue
how is necrotising fasciitis managed?
immediate surgical exploration- surgical debridement
do blood and tissue cultures after but do not delay surgery for results
IV abx and supportive care
what is erythema multiforme?
inflammation of the skin and mucous membranes
what type of reaction is erythema multiforme?
type IV
what organisms cause erythema multiforme?
herpes most commonly
mycoplasma
HIV
can be due to drug reactions- sulphonamides
what organism is likely to cause erythema multiforme?
herpes
what does erythema multiforme look like?
target lesio with a central vesicle/crust
ring of pallor or erythema around it
often starts in the hands and spreads up
what are signs and symptoms of erythema multiforme?
prodrome of fever, aches
tender/itchy/painful target lesions with a central vesicle/crust, they have a ring of pallor or erythema
how is erythema multiforme managed?
if minor (only involves skin)- topical emollient and oral corticosteroids if major (involves skin and mucosa)- topical emollient and oral/IV corticosteroids
what is molluscum contagiosum?
a skin infection due to the molluscum contagiosum virus
what does molluscum contagiosum look like?
smooth papule that is umbilicated
may be itchy
painless
how is molluscum contagiosum transmissed?
close contact eg sexual, swimming pools
how is molluscum contagiosum managed?
observation
topical potassium hydroxide
cryotherapy 2nd line
what are pressure sores?
localised damage to skin/soft tissue over bony prominences due to prolonged pressure
what are rf for pressure sores?
immobility
sensory impairment
older age
describe lesions in pressure sores
in tact skin or open wound (superifcial or deep)
what ix are done for pressure sores?
consider doing a wound swab
ESR, CRP
how are pressure sores managed?
1st line= reposition, reduce pressure
clean and dress them, analgesia, diet
