dermatology Flashcards
pyoderma gangrenosum
what is it?
inflammatory disorder (non-infectious) causing v painful skin ulceration
it is rare
pyoderma gangrenosum causes:
idiopathic (50%)
IBD (10-15%)
rheumatological
haematological
granulomatosis with polyangiitis
PBC
pyoderma gangrenosum features: (4)
typically LL
sudden onset
small pustule/ red bump/ blood blister –> painful ulcer
systemic features: fever + myalgia
Necrobiosis lipoidica diabeticorum
what is it?
associated skin sign?
shiny, painless areas of yellow/red skin typically on the shin of diabetics
associated with telangiectasia
erythema nodosum features (4)
inflammation of subcutaneous fat
–> tender, erythematous, nodular lesions
usually occurs over shins,
resolves within 6 weeks
lesions heal without scarring
erythema nodosum causes
infection
streptococci
tuberculosis
brucellosis
systemic disease
sarcoidosis
inflammatory bowel disease
Behcet’s
malignancy/lymphoma
drugs
penicillins
sulphonamides
combined oral contraceptive pill
pregnancy
pretibial myxoedema
how does it look?
associated condition?
shiny, orange peel skin
Grave’s disease
sedating anti-histamines
i. example:
ii. other SE
i. chlorphenamine
ii. anti-muscarinic - dry mouth, urinary retention, blurred vision, constipation
non-sedating anti-histamines examples:
loratadine
cetirizine (but this is more sedating than other non-sedating ones xo)
erythema multiforme
what is it?
hypersensitivity reaction most commonly triggered by infections
erythema multiforme features
target lesions
initially on the back of the hands / feet then torso
UL>LL
sometimes mild itch
mucosal involvement in severe form
erythema multiforme causes
viruses: HSV (most common cause
idiopathic
bacteria: Mycoplasma, Streptococcus
drugs
connective tissue disease e.g. Systemic lupus erythematosus
sarcoidosis
malignancy
drug causes of erythema multiforme
penicillin
sulphonamides, carbamazepine
allopurinol
NSAIDs
COCP
nevirapine
lichen planus features:
4Ps
papules
Purple
Pruritic
Polygonal
on flexor surface
Wickham’s striae (white lines pattern)
often + oral involvement (white-lace pattern on buccal mucosa)
nails:
thinning of nail plate
longitudinal ridging
lichenoid drug eruption causes:
gold
quinine
thiazides
lichen planus mgt
potent topical steroids
benzydamine mouthwash or spray if oral lichen planus
oral steroids or immunosuppression if extensive
hyperhydrosis mgt
- topical aluminium chloride
- iontophoresis
- botox (licensed for axillary sx only at present)
- surgery
keloid scar mgt:
intra-lesional steroids e.g. triamcinolone
surgical excision if large
where do keloid scars most commonly occur
sternum > shoulder > neck > face > extensor surfaces of limbs > trunk
exacerbating factors for psoriasis
trauma
alcohol
drugs:
- BBs
- lithium
- antimalarials
- NSAIDS
- ACEi
- infliximab
streptococcal infections (trigger GUTTATE psoriasis)
shingles rx within how long of onset of rash
72hrs
pityriasis vesicolor
what is it ?
superficial cutaneous fungal condition associated with malassezia furfur
pityriasis vesicolor
predisposing factors
occurs in healthy individuals
immunosuppression
malnutrition
Cushing’s
pityriasis vesicolor
mgt
ketoconazole
if does ntp resolve send skin scrapings and consider itraconazole
shingles most commonly affected dermatomes
T1-L2
guttate psoriasis features:
recent hx strep throat
“tear drop” scaly papules on trunk & limbs
resolved in 2-3 months, mgt like psoriasis
SJS causes: (8)
penicillin
sulphonamides
lamotrigine, carbamazepine, phenytoin
allopurinol
NSAIDs
oral contraceptive pill
SJS features (5)
maculopapular rash with target lesions –>
may develop into vesicles or bullae
Nikolsky sign +ve - (blisters and erosions appear when the skin is rubbed gently)
mucosal involvement
systemic symptoms: fever, arthralgia
toxic epidernal necrolysis features:
systemically unwell e.g. pyrexia, tachycardic
positive Nikolsky’s sign: the epidermis separates with mild lateral pressure
drug precipitants of TEN (toxic epidermal necrolysis (6)
phenytoin
sulphonamides
allopurinol
penicillins
carbamazepine
NSAID
TEN mgt
stop precipitant
supportive care
ivIg
sometimes:
immunosuppressive agents (ciclosporin and cyclophosphamide), plasmapheresis
impetigo mgt:
hydrogen peroxide 1% cream if well
topical abx
- fusidic acid
- topical muciporin if fusidic acid resistance suspected
extensive disease:
- PO fluclox
- PO erythromycin if penicillin allergy
school exclusion in impetigo:
until:
- lesions crusted over
OR
- 48hrs from onset of rx
vitiligo associated conditions: (5)
type 1 diabetes mellitus
Addison’s disease
autoimmune thyroid disorders
pernicious anaemia
alopecia areata
chronic plaque psoriasis mgt
emollients
- potent topical steroids + vitD analogue OD
(apply separately, for 4 weeks)
if no improvements in 8 weeks
- vitamin D analogue BD
if no improvement in 8-12 weeks
- potent topical steroid BD
OR
coal tar OD
can also use short acting dithranol
chronic plaque psoriasis mgt in secondary care:
phototherapy
systemic therapy:
- methotrexate
- ciclosporin
- systemic retinoids
- biological agents: infliximab, etanercept and adalimumab
ustekinumab (IL-12 and IL-23 blocker) is showing promise in early trials
scalp psoriasis mgt:
OD potent topical steroids for 4 weeks
if no improvement try different formulation
face/ flexural/ genital psoriasis mgt
mild/ moderate potency steroids OD/ BD
FOR MAX 2 WEEKS
vitamin D analogues examples:
calcipotriol (Dovonex)
calcitriol
tacalcitol
(can be used LT)
seborrhoeic dermatitis
what is it?
inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur
seborrhoeic dermatitis features:
eczematous lesions in sedum rich areas -(nasolabial folds, periorbital, auricular)
otitis externa
blepharitis
seborrhoeic dermatitis mgt:
ketokonazole (topical anti-fungal)
short term: topical: steroids
pompholyx eczema
affects hands + feet
- blisters
- itch ++
pompholyx eczema
mgt
cooling
emollients
topical steroids
scabies mgt
- permethrin 5% is first-line
- malathion 0.5% is second-line
pruritus persists for up to 4-6 weeks post eradication
crusted (Norwegian) scabies
ivermectin
fungal nail infection mgt
- amorolfine nail lacquer
- PO terbinafine
PO itraconozole if due to candida
eczema herpeticum
i. causative organism
ii. mgt
i. HSV 1
(rarely coxsackie A16)
ii. iv aciclovir
(steroids make it worse)
acne rosacea mgt:
SPF/ concealer
if predominant erythema/ flushing:
- brimodine gel / PO propanolol
papules/ pustules
1. topical ivermectin
2. topical azelic acid
3. topical metronidazole
4. topical ivermectin + PO doxycycline
^^ PO retinoids if this fails
mild- mod acne mgt
combination of any 2 of the following:
topical benzoyl peroxide
topical abx (clindaymycin)
topical retinoids (tretinoin/ adapalene)
acne rosacea
refer to secondary care if:
sx not improved with optimal primary care mgt
rhinophyma
