dermatology Flashcards
yellow, greasy non pruritic scales on the scalp, classically with no underlying erythema, seen in babies
likely diagnosis?
Infantile Seborrhoeic Dermatitis, more commonly known as Cradle Cap
Tx for cradle cap
emollient (moisturiser) to help loosen the scales
then gently brush baby’s scalp with a soft brush and then wash it with baby shampoo
RF for atopic dermatitis
allergic rhinitis (hayfever),
age <5 years,
family history of eczema,
PMH/FH of atopy (food allergies, asthma)
contact dermatitis vs atopic dermatitis
contact dermatitis
- results from external factors
- type 4 hypersensitivity
- tested for vis skin patch test
atomic dermatitis
- internal skin condition
- type 1 hypersensitivity (IgE)
- tested for via skin prick tets
sites of involvement of atopic dermatitis in infants
cheek
forehead
extensor surfaces
sites of involvement of atopic dermatitis in children
flexures - particularly the wrists, ankles, and antecubital and popliteal fossa
2 signs of chronic atopic dermatitis
lichenification (thick leathery skin due to constant scratching)
hyperpigmentation
what medical emergency can present in children with atopic dermatitis
eczema herpeticum - presenst as rapidly growing painful rash
describe the presentation of eczema herpeticum
rapidly growing painful rash
punched out lesions
commonly seen in children with atopic dermatitis
cause of eczema herpeticum
HSV 1 or 2
Tx for eczema herpeticum
IV acyclovir - urgent as can be life threatening
levels of what are elevated in atopic dermatitis
IgE
Ix for atopic dermatitis
IgE levels
skin prick testing
Ix for contact dermatitis
skin patch testing
Tx for atopic dermatitis, normal and in severe cases
Emollients → improve skin barrier function by rehydrating the skin
Topical Corticosteroids → hydrocortisone
Severe Cases ⇒ systemic immunosuppressive agents (Oral Ciclosporin)
common causes of viral exanthema
chickenpox (varicella),
measles,
rubella
what is viral exanthema and where on body is it usually found
Widespread skin rash accompanying a viral illness
more likely to occur on trunk
Ix for viral exanthema
viral swab
blood tests
Tx for viral exanthema
Antipyretics → paracetamol
Moisturising emollients to reduce itch
where do pressure sores usually happen
over a bony prominence eg sacrum or heel
RF for pressure sores
immobility,
recent surgery
intensive care stay,
diabetes,
malnutrition
what score is used to screen for pts who are risk of developing pressure sores and what does it take into account
Waterlow score
Takes into account
BMI,
nutritional status,
skin type,
mobility
continence
stages 1-4 of pressure ulcers/sores
Stage 1 ⇒ nonblanchable erythema of intact skin.
Stage 2 ⇒ loss of dermis +/- epidermis. Superficial ulcer.
Stage 3 ⇒ loss of all skin layers (full thickness).
Stage 4 ⇒ extensive destruction, tissue necrosis, or damage to muscle, bone or supporting structures
describe the erythema in pressure sores/ulcers
non blanchable
what are the clinical features of a pressure sore/ucler
over bony prominence eg scream/heel
non blanch able erythema
described skin perfusion (^CRT)
painful - (different from neuropathic ulcers which are painless)
signs of wind infection eg purulent drainage, foul smell
Ix for pressure sores
Evaluate for predisposing factors → blood glucose, HbA1C, serum albumin (assess malnutrition)
Check for infection → leukocytosis and increased CRP
management of pressure sores/uclers
Pressure relief over affected area
Frequent position changes (every 2 hrs) for immobile patients
Moist wound environment (encourages ulcer healing)
Analgesia (paracetamol, ibruprofen)
Ensure good Nutrition
Wound Management → cleaning & dressings
management of stage 3/4 pressure sores/uclers in pt who are and aren’t suitable for surgery
Debridement of necrotic tissue (if not suitable for surgery)
Surgical debridement and reconstruction with flap formation (if suitable for surgery)
which layers of the skin are infected in cellulitis
deep dermis and subcutaneous tissue
most common causative bacteria of cellulitis
Streptococcus pyogenes (catalase -ve)
Staphylococcus aureus (catalse +ve)
RF for cellulitis
obesity
diabetes,
venous insufficiency,
eczema,
oedema
describe the skin, lesions and systemic symtopoms of cellulitis
red painful hot swelling
poorly defined lesions
fever, chills, nausea, headaches
what is erysipelas in cellulitis and what is it cause by
causes well defined lesion
More superficial, limited version of cellulitis
Caused by streptococcus pyogenes.
where does cellulitis most commonly occur
legs (shins)
Ix for cellulitis
Clinical Diagnosis → only request further tests if signs of systemic illness or septicaemia
High WCC and CRP
Skin Swab MCS → can identify pathogen and antibiotics susceptibility
If patient admitted and septicaemia suspected → blood cultures and sensitivities
which classification is used to guid management of cellulitis
ERON classification
class I, II, III of cellulitis and how to manage each
Class I (no systemic systems or co-morbidities) → managed in primary care with oral antibiotics
Class II (systemically unwell or systemically well with co-morbidity) → short term hospitalization
Class III (significant systemic upset)
or IV (sepsis or nec fasc) → urgent hospital admission
first line Tx for mild/moderate cellulitis, and what is the replacement if have penicillin allergy
Flucloxacillin → 1st line treatment for mild/moderate cellulitis
If Penicillin Allergic → clarithromycin, erythromycin (in pregnancy), or doxycycline
Tx for cellulitis if severe systemic symptoms (eg. septic signs, tachycardic + hypotensive) or significant comorbidites
hospital admission + IV co-amoxiclav, cefuroxime, clindamycin or ceftriaxone
what can psoriatic skin manifestations be made up of
plaques
papules
describe the papules in psoriasis
erythematous
circumscribed / well demarcated
scaly
purple / silver
what pathophysiology causes the papules and plaques in psoriasis
abnormal T cell activity –> stimulates keratinocyte proliferation
describe the clinical course of psoriasis
relapsing course, with symptoms free intervals
describe the 3 types of psoriatic skin problems
plaque psoriasis
- raised inflamed plaque lesions with a superficial silvery-white scaly eruption
flexure psoriasis
- skin is smooth.
Occurs on skin creases or flexures (ie. groin, armpits).
guttate psoriasis
- widespread, erythematous, fine, scaly papules (water drop appearance) on trunk, arms, and legs.
The lesions often erupt after an upper respiratory infection (frequently triggered by a streptococcal infection- fever and sore throat)
what exacerbates and relieves plaque psoriasis
exacerbates: BBs, NSAIDs, ACEi, lithium
receives: sun exposure
what triggers guttate psoriasis
URTI esp strep infection
Tx of guttate psoriasis
phototherapy
in psoriasis in which order do arthritis and skin manifestations happen
1st arthritis, then skin lesions develop
describe psoriatic arthritis pattern and what the 2 main features are
asymmetrical arthritis pattern
2 main features
1. DIP swelling - “pencil in cup deformity”
2. dactylitis (sausage fingers)
which gene is psoriatic arthritis linked to
HLA-B27
Tx of psoriatic arthritis
NSAIDs and DMARDs (methotrexate)
which medication should be avoided in psoriatic arthritis to avoid skin lesion flare ups
oral steroids
describe nail manifestations of psoriasis
pitting
onycholysis (seperation of the nail from the nail bed)
what is Koebner phenomenon
skin lesions caused by trauma (physical stimuli or skin injury)
what is Auspitz sign
small pinpoint bleeding when scales are scraped off
1st and 2nd line treatment
1st line
topical corticosteroid (hydrocortisone) + topical vitamin D analogue (calcipotriol)
Corticosteroids reduce inflammation, Vitamin D reduced keratinocyte proliferation
2nd line
Phototherapy (secondary care) → narrowband ultraviolet B light
what is 1st line systemic Tx for psoriasis
oral methotrexate
why should steroids for psoratic skin conditions not be used for more than 8 weeks
can cause
- skin atrophy
- rebound symptoms
- striae
what’s another name for urticaria
hives
describe the lesions of urticaria
“wheals”
BLANCHING
smooth
raised skin
oedematous
pruritic
painless
erythematous
rapidly developing (minutes)
short lived (<24hrs)
leaves no skin markings once resolved
is urticaria blanching or non blanching
BLANCHING
contrast causes of acute or chronic urticaria
acute: allergy
chronic: exposure to heat/cold, pressure, sunlight, vibration, Ach release, water
which drugs can cause urticaria
aspirin
penecillin
NSAIDs
opiates
what are urticaria marks called
wheals
what other swelling is urticaria associated with
angioedema (swelling of face, tongue, lips)
what is urticarial vasculitis
chronic / recurrent urticaria due to affected small blood vessels in the skin
what Ix do you do if you suspect urticarial vasculitis
CRP and ESR
1st line Tx for urticaria
Trigger identification & avoidance
antihistamine (loratadine or cetirizine)
Tx for severe / recurrent episodes of urticaria
prednisolone
which part of the skin does necrotising fasciitis affect
subcutaneous soft tissue
contrast type 1 and 2 necrotising fasciitis
type 1 (more common)
- polymicrobial
- aerobes and anaerobes
- common in diabetics following surgery
type 2
- monomicrobial
- strep pyogenes
RF for necrotising fasciitis
immunosuppressed / diabetes
SGLT2 inhibitors
IVDU
surgery
cutaneous trauma
varicella zoster infection
most common site for necrotising fasciitis
perineum - fourniere’s gangrene
describe presentation of necrotising fasciitis
acute onset
erythema and oedema
systemic features of infection:
- hypotension
- tachycardia
- palpitations
-N&V
- fever
- tachypnoea
- lightheadedness
2 signs of advanced necrotising fasciitis
delirium
crepitus
Ix for necrotising fasciitis in order
1) surgical exploration
2) bloods and tissue culture
Tx for necrotising fasciitis
urgent surgical debridement
Abx (give empirical first, then specify when cultures come back)
which pts have higher mortality with necrotising fasciitis
patients who develop shock and end-organ damage
what virus causes chicken pox
Varicella zoster virus (VXV)
what does HSV1 primarily cause
oral and genital herpes
what does HSV2 primarily cause
genital herpes
what is the name for severe inflammation of most of the body’s skin surface - redness, scaling
erythroderma
what is sezary syndrome
erythroderma + lymohadenopathy + heaptosplenomegaly
itchy red rash of pustules in an area around hair follicles, most common on neck / armpit / groin
diagnosis?
folliculitis
very itchy red rash made of small red lesions in the groin area
likely diagnosis
scabies
what colour are genital warts
flesh coloured
prognosis of varicella zoster in children vs adults
children: self limiting
adults: associated with complications, such as secondary bacterial infection, encephalitis, and pneumoni
pushed out lesion with well emaciated edges
painful
arterial insufficiency
prolonged CRT
poor pulses
ischaemic changes eg hair loss, smooth shiny skin
diagnosis
arterial ulcer?
ulcer after physical insult to area, hemosiderin deposition
diagnosis?
traumatic ulcer
this is secondary to vascular insufficiency and the hemosiderin deposits here suggests underlying venous insufficiency.
painful ulcers
usually affects legs
cribriform healing pattern
undermined edges
violaceous borders
associated with IBD
can be caused by minor injury to area: starts off as small red lesion then rapidly widens and deepens
diagnosis?
pyoderma gangrenosum
causes of erythroderma
Dermatitis: Atopic dermatitis, seborrhoeic dermatitis, contact dermatitis
Psoriasis
Pityriasis rubra pilaris
Drug allergies
Idiopathic triggers
Sezary syndrome, a type of cutaneous T-cell lymphoma, which leads to erythroderma, lymphadenopathy, and hepatosplenomegaly. It is defined by the presence of Sezary cells, which are atypical T cells, in the peripheral blood circulation.
purpuric rash
abdo pain
arthralgia
diagnosis?
henoch-Schonlein purpura
what is telangiectasia
spider veins
(small, red and purple clusters)
what does CREST syndrome entail
Calcinosis: Calcium skin deposits
Raynaud’s phenomenon
Esophageal dysfunction:
Sclerodactyly: Skin damage on fingers - tight shiny skin on fingers, causes them to curl at tip
Telangiectasia: Spider veins
another name for CRESt sydrome
limited cutaneous systemic sclerosis
which antibodies are associated with CREST syndrome / imited cutaneous systemic sclerosis
anti centromere antibodies
what is erythema nodosum
tender, red bumps, usually found symmetrically on the shins
prodromal illness followed by the sudden appearance of a widespread, painful, erythematous rash.
A least two mucosal sites are involved
diagnosis?
Stevens-Johnson Syndrome (SJS)
causes of Stevens-Johnson Syndrome (SJS)
usually adverse drug reaction
Sulphonamides (such as Co-trimoxazole),
Beta-lactams (such as Penicillin)
anti-convulsants (such as Phenytoin).
pt has UTI for which she starts taking medication, the develops painful sudden inset rash and ulcers on lips and genitals
what is the diagnosis and the cause if it
stevens-johnson syndrome
caused by cotrimoxazole (med for UTI)
pt has bacterial tonsillitis and sore throat followed by rash on her shins. what is the cause of her erythema nodosum
strep pyogenes
describe the rash seen in meningitis
non blanching
palpable
purpuric
what is erythema multiform
dye to allergic reaction to medication of infection - esp HSV
eruption of target lesions spreading from the distal limbs to the trunk
only affects ONE mucosal site
if pt with psoriasis on education develops swollen gums, which med likely caused this
ciclosporin
cyclosporin side effects
the 5 H’s:
hypertrophy of the gums,
hypertrichosis (excessive hair growth)
hypertension,
hyperkalaemia
hyperglycaemia (diabetes)
what abdominal issue can occur with Henoch-Schonlein purpura
intussusception
describe the rash in Henoch-Schonlein purpura
Henoch-Schonlein purpura
presents with bio pain, arthirtritis, renal issues, intussusception
which medication worsens psoriasis
beta blockers, ACEi, NSAIDs, lithium
what is herpes zoster (shingles) caused by
reactivation of varicella zoster virus
how does herpes zoster present
unilateral blistering lesions with sensory derangement - common in immunocompromised
Tx for herpes zoster
mild = analgesia and calamine lotion
seere = acyclovir
history of stress and scratching,
one single play on back of neck or perineum
diagnosis?
lichen simplex chronicus
what is tuberous slcerosis
rare genetic condition that causes mainly non-cancerous (benign) tumours to develop in different parts of the body
tuberous sclerosis skin manifestation
angiofibromas - firm pales in a butterfly distribution across face
shagreen patch - Leathery patch on sacrum, that is dimpled like orange peel
fleshy tumour that grow from nail folds
ovals of hypo pigmented skin that fluoresce under wood’s light
what are dermatophytoses
fungal infection of skin and nails
triggers for psoriasis
Skin trauma (Koebner phenomenon)
Infection: Streptococcus, HIV
Drugs: B-blockers, Anti-malarials, Lithium, Indomethacin/NSAIDs (BALI)
Withdrawal of steroids
Stress
Alcohol + smoking
Cold/dry weather
characteristic feature of impetigo
gold crusting
what should you remember about the distribution of intermittent claudication
it is BILATERAL
which medication us used in the treatment of pruritus due to biliary obstruction
cholestyramine
respiratory symptoms
erythema nodosum
no recent travel history or contacts
likely diagnosis?
sarcoidosis
(lack of travel history makes TB less likely)
acute hypersensitivity reaction with limited or no mucosal involvement
target lesions
occurs after infection - esp HSV (presents w cold sores on lips)
erythema multiform
what presents with target lesions
erythema multiform
what presents with annular lesions
Tinea infections, caused by a dermatophyte fungus commonly known as ringworm
what presents with discoid lesions
discoid eczema
discoid lupus erythematosus
what is the name for painful open pustular ulcers that have a blue overhanging edge, and which condition are they commonly seen in
pyoderma gangrenosum
IBD
dermatological manifestation of TB
scrofuloderma,
a cold, painless abscess in then which can ulcerate
erythema nodosum - raised red ender rash on shins
what is given to a pt with urticaria who hasn’t responded to antihistamines
oral prednisolone
which condition has a flu like prodrome followed by the development of an erythematous macular rash with ulceration of the pharynx and buccal mucosa
Stevens–Johnson syndrome (SJS)
what is erythroderma and how does it present
serve inflammation of most of body’s skin surface
redness and scaling
starts in patches and then spreads all over body
life threatening
“Generalised erythema, pruritus and scaling”
causes of erythroderma
psoriasis
reaction to medication
what is Seborrheic dermatitis
common skin condition that mainly affects your scalp. It causes scaly patches, inflamed skin and stubborn dandruff.
affects oily ares of skin which produce sebum
describe the appearance of a wheal
raised lesion - skin coloured swelling
surrounded by erythema
what is Toxic epidermal necrolysis
life-threatening skin disorder characterized by a blistering and peeling of the skin. This disorder can be caused by a drug reaction—often antibiotics or anticonvulsives.
raised red tender rash seen symmetrically on shins
and pt is having trouble breathing
diaganosis?
erythema nodosum
caused by TB or sarcoidosis
bullseye rash occurs after tick bite
- associated with Lyme disease
diagnosis?
erythema migrans
what is compartment syndrome and when/where is pain felt
commonly occurs after fracture of leg
swelling/tightness -> raised pressure reduces blood supply, causing tissue necrosis
pain is in the front leg and is worse on pass ankle dorsiflexion
(no blisters/blackened appearance of skin)
pt injured themselves and now has a rash on same area. what is the term given to this presentation?
Koebner’s phenomenon
(occurs in psoriasis)
what condition does Hyperproliferation of cells causing a decreased skin turnover time cause
psoriasis
what does a genetic defect in the skin barrier
atopic dermatitis
what medication should be used and what should be avoided for the pain associated with chicken pox
use paracetamol
avoid NSAIDs eg ibuprofen as can cause necrotising fasciitis
when can a child with chicken pox return to school
when all the lesions have crusted over
which condition is mucous membrane involvement characteristic of
Steven-Johnson’s syndrome
which bacteria cause impetigo - rash with honey coloured crusts
staph aureus
strep pyogenes
erythema nodosum vs dermatitis herpetiformis
erythema nodosum
- painful patches on legs
- caused by IBD
dermatitis herpetiformis
- itchy, blistering
- caused by coeliac disease
describe a venous ulcer, and what 2 other features are likely to be seen on the legs as well
painless
granulated pink-red base
medial aspect of lower leg
associated with oedema and varicose veins
purple - flat topped plaques appearing on skin
very itchy
pt recently started new med
diagnosis?
lichenoid eruption
girl has had rashes before but has suddenly presented with a new different looking one (multiple red, monomorphic blisters and erosions across her face and neck)
she has a fever and feels unwell
diagnosis and Tx?
eczema herpeticum as a complication of atopic eczema
IV acyclovir
first and second line Tx for impetigo
1st: topic abx (fusidic acid or mupirocin)
2nd: oral abx (flucloxacillin)
usual cause of itchy rash which is limited to just the hands
contact dermatitis
which condition causes target lesions and was is the most common cause of this condition
erythema multiforme
HSV
where do psoriasis plaques most commonly appear
extensor surfaces of elbows and knees, scalp
pt develops scaly rash after finishing his GCA (giant cell arteritis) Tx
diagnosis?
psoriasis
(withdrawal from steroids can cause psoriasis)
what is Henoch-Schönlein purpura or HSP also known as
IgA vasculitis
which condition has a triad of purpura (red blots due to bleeding under skin), arthritis and abdo pain (can also have haemoptysIs)
IgA vasculitis aka HSP
when should topical corticosteroids be prescribed or atopic eczema
when the pruritic is severe enough to cause excoriations
which medication would you prescribe to a pt with primary biliary cirrhosis to relieve their pruritis
cholestyramine
features of scarlet fever
strawberry togue
white patches on swollen tonsils
red throat
swollen lymph nodes
fever
headache
rash
common causes of rash on extensor surface
psoriasis
dermatitis herpetiformis
erythema multiform
some types of eczema (atopic eczema in infants, children is on flexures)
when should methotrexate not be used for psoriasis
pregnancy
what must be avoided whilst taking methotrexate for psoriasis
alchohol
side effects of methotrexate
myelosuppression, pulmonary fibrosis and liver fibrosis
when is phototherapy used for psoriasis
when the disease is extensive and non-responsive to topical therapies
what does haemosiderin deposition look like and what is it suggestive of
patch of darker skin eg brown
suggests venous insufficiency
which type of white blood cell is associated with contact dermatitis
T lymphocytes
which antibody is most likely to be found in SLE, and which antibody is used to diagnose LSE
Anti-nuclear antibody (ANA) = most common
Anti-dsDNA antibody = most specific –> sue for diagnosis
which condition has Anti-cyclic citrullinated peptide (anti-CCP) antibody
rheumatoid arthirits
which condition has Anti-cardiolipin antibody
antiphospholipid syndrome
how does erythema multiform rash spread across the body
starts on the palms/soles and then spreads out
what type of medication is methotrexate
an anti-folate medication, hence inhibiting the synthesis of DNA and inducing immunosuppression
pyoderma gangrenosum vs SJS
both cause blistering lesions
pyoderma is typically located to one region eg legs
SJS affects widespread area and mucosal membranes eg mouth/lips
“erythema of the cheeks that spares the nasolabial folds”
likely diagnosis?
SLE
Ix for SLE
serum autoantibodies - anti dsDNA
Nikolsky’s sign and which condition it is seen in
a rash that peels when pressure is applied
SJS
main features of SJS
blistering rash
a rash that peels when pressure is applied (Nikolsky’s sign)
mucosal ulceration
prodromal flu like illness
features of SLE
malar rash
discoid lupus erythematosus
photosensitivity
alopecia
Subacute Cutaneous Lupus Erythematosus - lesions triggered by UV exposure
ulcers/vasculitis
myalgia
arthralgia
Tx for pyoderma gangrensosum
1st line: prednisolone (oral or topical)
and line: immunosuppressants
which STI can cause erythema nodosum
chalmydia
first line Tx for pts with venous insufficiency
compression bandaging
how does sunlight affect SLE vs psoriasis
worsens SLE - Discoid lupus erythematosus is the development of red scaling plaques in sun exposed areas of skin
improves plaque psoriasis
what is used to confirm diagnosis of SJS
skin biopsy
which auto antibodies could be present in a pt with dermatitis herpetiformis
Anti-tissue transglutaminase (anti-TTG) antibodies –> underlying diagnosis of coeliac disease
what is another word for athletes foot
tinea pedis
management of dermatitis herpetiformis
dapsone (antibiotic)
as well as maintaining glute free diet to manage the cause - coeliac disease
On examination there is a large, erythematous, scaly patch across 3 toes and part of the dorsum of his left foot. There is an area of central clearing and the outer edge appears most inflamed.
diagnosis?
tinea pedis / athletes foot
